View Full Version : Boss Smarthitch 2 problems
Recently purchased a used boss plow. Has the smarthitch 2. Plug everything together and hitch raises just fine. Problem is it won't go back down. Nor will the plow raise. When trying to put hitch back down the hydraulic cylinder wants to push down, same when trying to raise the plow. Upon advice of 2 different dealers I replaced both the smarthitch valve and the raise/lower valve. I also tried to replace the DPDT switch to no avail. Anyone with any ideas?
dsup
Did you actually change the valve cartridges or just the coils? Have you checked circuit for power with a test light when you activate the SH2 switch to dismount it? Are both valves operating electrically when you do it?
Do you have any idea what year the plow is?
Yes, I changed both valves, not the coils, as they tested good. When the switch or controller is activated I have 12 volts at the coils and I can hear a click when activated. I was told the plow was 4 years old when I bought it. It had been stored in an open shed for most of that time. Like I said the cylinder operates but instead of retracting to raise the plow it extends and pushes down. Same with the smarthitch, it activates with downward pressure either way the switch is thrown. Just more power when the switch is activated for raising the tower. (cylinder pushing down) I have tested the truck side plug with my tester and all circuits test good for which button is activated on the controller. When I bought it, I transported it home on the face of the blade in the back of my truck, would that have messed up anything internally? The blade angles just fine.
dsup
Transporting it face down on the blade shouldn't cause any issues whatsoever. Did you recieve the manual for the plow? If not go to http://service.bossplow.com/DocumentList.aspx?CategoryID=6&Type=1 and get the manual you need. if it asks for a serial number group use the serial number tag on the push quadrant tag, not the one on the blade to make sure you have the proper manual.
Did you see the plow function before you bought it? Did it operate properly at that time? Has anyone touched the drop speed valve on the back of the light tower? If it has been slowed too much that can cause this type of symptom.
If you look around page 11 of the manual you will see the smarthitch 2 wiring diagram. Is it wired EXACTLY like that? There are 2 symbols that are diode symbols with one where the ground (brown wire) fastens to the tower and one where the smarthitch 2 switch (white) wire is connected to the switch. A diode is like a check valve that only allows electricity to flow one way thereby not allowingg other components to be activated when the smarthitch feature is activated. This is likely the issue from what i can say from here without seeing it. You can pick up a new diode at any radio shack or simular store and solder it in and re shrink tube over it to protect it. I am not trying to be too simplistic but I do not know what your level of experience with some of this is so I am trying to make it clear.. By removing the jumper with the diode in it you can apply voltage to one side and check the other side with a test light and then apply voltage from the other side and check it again. testing from one direction your testlight should light and testing the other direction it shouldn't.
Let me know what you find.
I do have the manual, this person I bought it from is a retired sheriff from a neighboring county and he had had it removed by a local boss dealer. Watching it function beforehand was not an option. I have not done anything to the drop speed valve. I will go and recheck all the wiring. One of the first things the tech asked me to test for was that diode on the white wire at the switch. He had me test it for continuity, but from what I understand you are saying is that voltage should be tested for one way power is that correct? Also, I was not aware of the diode on the ground wire. I will look for that one and test it also.
I do have the manual, this person I bought it from is a retired sheriff from a neighboring county and he had had it removed by a local boss dealer. Watching it function beforehand was not an option. I have not done anything to the drop speed valve. I will go and recheck all the wiring. One of the first things the tech asked me to test for was that diode on the white wire at the switch. He had me test it for continuity, but from what I understand you are saying is that voltage should be tested for one way power is that correct? Also, I was not aware of the diode on the ground wire. I will look for that one and test it also.
Yes... checking it for continuity is ok if you check it in both directions. If it has continuity in both directions it is not good but since some testers use so low of a voltage i prefer to test them at operating voltage
O-K, I hoped that I was getting somewhere. The diode tests continuity both ways as well as voltage both sides. Now this is where it gets confusing. According to the website Fig 34 Standard Duty Manifold Wiring Diagram, this is not what is shown on the label on the pump. Looking at the back of the switch the orange wires are the same top left to bottom left to middle right. Bottom right has a black wire with the white diode wire converging. The diode wire goes to top right converging with another white wire. The black/white wire form the harness goes to middle left. Which wiring diagram should I go with?
Forgot to mention that I did not find a brown wire with a diode in it.
OK... Check and see what the serial number is as I told you before. Not the blade but the one on the pusframe quadrant. let me know what it is. also, do your coils ground through the valve cartradge stem nut that holds the coil onto the stem?
The serial number is E 7779. The coils have their own spade for the ground wire. There is no ground wire on the stem/nut itself.
OK... so all the spades are looped together for the grounds correct? and you said they are all landed but there is no diode, correct? and that serial number came off a white tag on the pushframe quadrant?
in the lower right hand corner of your manual there is a number STB03278-XX
what are the numbers where i have XX
Go here.. http://service.bossplow.com/Documents/stb03278.pdf Look at page 11 figure 19.. Make your plow look like this diagram... it should work then. by the sounds of it you Blk/White and White is in the wrong place. it should be top right, not bottom right.. Bottom right should be a black jumper
All grounds are looped correct and no diode. The serial # came off of the white tag on the push frame. The number is 7. Complete # STB03278-7
If that plow is only 4 or 5 years old then i do not believe that is the correct manual. Look at the link i sent you and see if that one looks right for what you have. if it does then make your look like that and it should work... tou may want to consider adding the diode to the ground if it does
I wired per instructions. When I pulled up on the switch all all get is a click. When I push down the tower raises slowly. I put the pins in and went to raise the plow and it still wants to push down on the cylinder. Although I don't believe the hoses are incorrect, (Certain lengths only reach certain spots) could they be backwards? Although I am still confused by the lack of reaction when switching up on the smarthitch. Could I have put the diode backwards when rewiring?
Would the lack of diode on the ground be the culprit also? I plan on going in to town in a bit. Which diode should I ask for? Reaching back on some of my schooling the triangle indicates which way the power is flowing and the line is the "backcheck" correct?
Yes, you could have... a diode is a check valve and if it is in backwards it won't let it work correctly
OK. I switched the diode around and that cured the up switch working, but I am back to downward pressure on the cylinder when trying to raise the plow or lower the tower.
Did you look at the manual i sent you the link for? Is that your plow?
The manual online you sent a link for says RT3 Straight Blade Installation Manual. The one that came with the plow says RT3 Straight Blade Installation & Owners Manual. Information off of the pump says that the plow is an RT3, and it has the smarthitch option. The only difference I can see between the two manuals is the wiring diagram for the switch. The plow itself is a straight blade 7'6" poly plow, although I don't believe that helps anything. I am sorry other than that I cannot tell the difference between the manuals and the plow. Is there something I am missing that can tell me the difference?
The manual online you sent a link for says RT3 Straight Blade Installation Manual. The one that came with the plow says RT3 Straight Blade Installation & Owners Manual. Information off of the pump says that the plow is an RT3, and it has the smarthitch option. The only difference I can see between the two manuals is the wiring diagram for the switch. The plow itself is a straight blade 7'6" poly plow, although I don't believe that helps anything. I am sorry other than that I cannot tell the difference between the manuals and the plow. Is there something I am missing that can tell me the difference?
Nope.. So long as it is an RT3 with the smarthitch 2 option this diagram would be correct. you have verified the all of the wiring is correct and we proved the diode was bad and corrected that. I have one last thing to try and that would be to remove the raise and lower coil and switch it with one of the 2 angle (the stacked ones). Try the functions again with those 2 coils switched and let me know
I have not been able to replace the diode other than reversing it. I will try and switch coils and let you know.
OK.. I misunderstood you. I thought you had changed the diode since it blocked the operation from working when it was reversed. it seems as though it is working. as far as the ground diode goes I have not seen a system without it so I would think it can't hurt to put one in.
Let me know how you make out after the coil flop
The angle coils would not fit the raise/lower valves (coil to big dia.) Tried smarthitch coil but did not make a difference.
I cannot get a diode today for the ground wire, will try that tomorrow.
the coils for raise and lower are the same coils and nuts as the angle coils. look at the parts list that was in the manual i sent you. the one for the smart hitch 2 is a different coil
One more thing to check. Again, look at the manual i sent you.. Page 24. it is a breakdown of the hydraulic manifold. # 30 F is a check valve. It would have been facing down while you hailed the plow on its face. It might be a stretch but take the check valve out and make sure its clean and not stuck towarnd the hex end. you may have bounced it hard enough to do that but i doubt it but it is worh checking too.
I will take out the check valve tomorrow after work. The angle coils on the side are bigger in diameter and did not have room to fit. I tried putting the raise/lower coils on the angle valve but that valve head is a bigger diameter and the coils would not slide on. Thank you very much for helping me trouble shoot this problem.
dsup
Did you have any luck after work yesterday? I am still leaning toward a weak coil in the raise/lower coil. Do you have a good digital multi meter? you can read the coil resistance and let me know what that is. Did you add the diode to the ground?
Just came in from working on the plow. I installed new diode and added a diode at the ground. Took out check valve, nothing I could detect wrong. I also took the lift valve that I had replaced Sat. and replaced the valve below the smarthitch valve. I was really confident this was it but to no avail. I did notice that there was some corrosion on this valve where the coil was on, could this be an indicator of something. I tried to remove the power to the upper left valve and noticed a small spark. But when removing power to the bottom coil no spark. I just read your last entry. I do not have a digital meter, but when using the multi tester I have it shows good continuity.
Well if this isn't an odd problem I do not know what is. If it was in float it would be likely that you wouls see a spark because it is keeping tha valve open so there would be voltage there and that would cause a spark when you opened the circuit. When you say there is corrosion on the cartridge stem, how much are we talking? I have seen badly neglected plows with no corrosion beneath the coil. Id there enough that you feel it could reduce the magnetic field enough not to open the valve?
Yes I do believe that, it was whitish in color. But I replaced that valve. I replaced it with the one I took out above. I did not replace the coil. Would you lean towards replacing that coil also? What would be the cost of a new coil or two? I am starting to lean towards getting the neighbor to load it into the back of the truck and taking it in.
Could I use steel wool on this valve and clean it up? Or inside the coil?
Yes.. you can clean the stem with no problem and an old toothbrush should clean the coil. Then if you can roll up a piece of sand paper you can clean the coil too. Can you swap that coil and your lift coil? they should be the same one. The one with the white wire (the corroded one) is the lift and the orange is the lower valve.
I plan on trying the clean up methods tomorrow after work. I will also flip the coils and try that. Thanks again for putting up with me.
I plan on trying the clean up methods tomorrow after work. I will also flip the coils and try that. Thanks again for putting up with me.
Give it a shot and let me know. I don't mind helping at all. It really is a simple product and is very reliable. Like I said before I have never seen corrosion on the stem like that and in the coil but if cleaning it does not work then flop the coils. If the problem follows the coil (it won't raise but will lower) when you flop them then you know it is the coil and if it doesn't then we will need to look further.
Give it a shot and let me know. I don't mind helping at all. It really is a simple product and is very reliable. Like I said before I have never seen corrosion on the stem like that and in the coil but if cleaning it does not work then flop the coils. If the problem follows the coil (it won't raise but will lower) when you flop them then you know it is the coil and if it doesn't then we will need to look further. Since when you "raise" the head gear you are actually lowering the plow and that is working fine we need to concentrate on the coil and valve that is actually the "lift" coil which has the white wire on it and is the one that has the corrosion. If the flop does nothing for it then we need to look at hydraulic pressures. When you say it angles fine I assume you are talking about flat on the floor since you cannot lift the plow and we can check a few things with that.
I know its a pain in the butt doing all of this but you are going to know this plow inside and out when its fixed and should be able to handle everything it throws at you. Coils run somewhere around 40 bucks from what I can remember and I always recommend keeping one on hand for middle of the night repairs although I cannot say I have ever needed one and a decent digital multi meter or even an anolog one is better than a test light because 9 volts will light a test light but may not pull a valve open. Low voltage is pretty common with any type of poor connection or damged cabling so they are handy to have around.
Well, I cleaned the coil and tried again. No luck. Switched all three coils in and out. No luck. What has got me really confused is that when raising it pushes down instead of retracting the cylinder. That in itself would have me believe that something was backwards, except when I try the smarthitch it wants to push down either way I throw the switch. Seems I have ruled everything out in the controls on the plow side. Would this leave it to the controller?
Well, I cleaned the coil and tried again. No luck. Switched all three coils in and out. No luck. What has got me really confused is that when raising it pushes down instead of retracting the cylinder. That in itself would have me believe that something was backwards, except when I try the smarthitch it wants to push down either way I throw the switch. Seems I have ruled everything out in the controls on the plow side. Would this leave it to the controller?
You said you checked all of the plow functions at the truckside connector and everything read OK.. For that reason i didn't suspect it. Yes, it could be but assuming you checked it as stated i doubt it. The check valve that you said appears OK could cause it as well. You are telling me that with all the coils connected but on different valves it reacted the same as it did so that rules out the coils.
You have made sure all the wiring in the maifold and smart hitch are the same as the manual. try disconnecting the orange wire from the coil which id the "lower" coil and then try and raise the plow. if the plow raises then the coil is picking up volrage when it shouldn't be. let me know if that does anything. If it lifts then we need to chase where it is coming from. If it doesn't then we need to look at the valves themselves. You said you chanbed one of the valves. Did you chanbe the one below the smarthitch 2 valve or the one to the left of it?
Since you didn't know that the lift valve had corrosion on it until yesterday I assume you changed the "lower" valve which is to the left of the smarthitch 2 valve. Try taking the valve you removed previously that i believe came from the left side of the SH2 valve and replace the "lift" valve (the one below the SH2 valve) with it.
People get confused when they see the manual and see lift?lower and assume it is the same valve but it is not. It is called out that way only because the lift and lower valve uses the same valve as far as part numbers go. Same thing goes for the coils. Try it out and let me know. If this don't work i only know one other thing to try.
What I have done regarding valves is that the smarthitch valve is new. The upper valve to the left is new. That valve went to the valve below the smarthitch.
What I have done regarding valves is that the smarthitch valve is new. The upper valve to the left is new. That valve went to the valve below the smarthitch.
OK... what i would do now is disconnect the orange wire from the coil amd the black wire from the smart hitch 2 coil and see if the plow raises.
I took off the orange and ground leads. Same results. Took off the white leads and ground. Same results. Took off the smarthitch. Same results. Took off the leads the smarthitch switch. Same results. Took off all leads to all coils. Same results, It tries to extend (push down) the cylinder, albeit not as strong as when using the smarthitch to raise the tower.
I took off the orange and ground leads. Same results. Took off the white leads and ground. Same results. Took off the smarthitch. Same results. Took off the leads the smarthitch switch. Same results. Took off all leads to all coils. Same results, It tries to extend (push down) the cylinder, albeit not as strong as when using the smarthitch to raise the tower.
Do you have access to a pressure guage that will read 4000 PSI?
OK... I am leaning toward the check valve but i don't want to have you buy parts without knowing for sure. It is either that or a pressure relief valve i am thinking. I know it will sound stupid but you did check the fluid, didn't you? and tou checked it as outlined in the manaul because they tend to loose fluid when stood on the blade face.
Yes, I have checked the fluid, and did add 1/2 quart a while back.
I know it seemed stupid but i had to ask... One more thing you can try to prove it out is to reverse the lift cylinder hoses and see what happens. that might rule out an issue with the lift cylinder leaking by.
Without reconfiguring the els, the hoses won't reach. Is there any other ideas besides the check valve or pressure relief valve.
I was just reading the reply where you took off the leads... you said you took off the white leads which i didn;t want you to do because that is the "lift valve. Did you take off the orange and the black leads at the same time like i wanted you to do and then try lifting?
Sorry I did not reply sooner, I must have lost my internet connection. I must not have read that close enough. I did remove the orange leads and ground leads. I did not remove just the orange and black leads, sorry. I will try that tomorrow. Thanks again.
DSUP
I have been racking my brain on this and i just want to make sure we touched all the bases. Just take a look at this and make sure it is working this way.
1. Take off the orange and the black leads at the same time like i wanted you to do and then try lifting the plow with the controler
2. You need to have power on both the raise and lower (white and orange) when you try to power it down off the truck. When detaching you should NOT have power on the SH2 valve. Make sure that is working like that.
3. Have you pulled down on the headgear without powering it down to remove it from the truck? If you have in rare instances it can make an air pocket in the hydraulic cylinder that coauld cause the same issue. you would need to bleed the system by cracking a fitting loose and running the pump until fluid came out. you would have to do it on both lines where they enter the lift cylinder.
4. Make absolutley sure you did not put the SH2 valve in the wrong place when you did your install originally. Like i said earlier, The raise and lower are the same but the SH2 valve although it looks quite a bit like it is different in function.
5. The drop speed control valve on the back of the plow tower can cause some issues and thats why i asked earlier about that. although you said you didn't touch it try this. Turn the adjustment all the way in and then back it out 1 & 1/2 turns. Thats where it is set from the factory. If that doesn't work, back it out one more turn and try it. If no difference then return it to the 1 & 1/2 setting.
If these things check out electrically and the adjustment to the valve does not do it then we will need too look at the controler.
Hopefully we will find the answer in the above but if not then we can bypass the controler and power the circuit manually without the controller using jumper wires and see if we can make it work before you lay out money for a controler.
#1, still wants to push out on the cylinder.
#2, NO power on black/brown leads to SH2
#3, Yes I had pulled down on the headgear, I was aware of consequences. I am pretty sure I have bled out the air.
#4, Absolutely sure I did not mix up valves.
#5, Tried and set back to factory setting.
OK... So number 2 you did not have any power on the Black which is good. I assume you did have power on the Orange and the White when you try to power it off the truck... Correct?
Regarding #2, power to white when activating SH2. Power at orange all the time even when not activating SH2, is this correct? It actually drops voltage when activating SH2.
Orange is the "lower" valve and is to the left side of the SH2 valve. If it is in float it will have power to it. When you say it has power all the time do you mean it is in float? If it is not in float then it should not have power... check it and let me know
Yes, when it is in float. No power when not.
Yes, when it is in float. No power when not.
Can you have someone hold it in the up position with the controler and test and see what coils have power?
With the hand held controller in the up position, only the white wire has power.
i hate to say it but you need to either get a pressure guage that will go to 4000 PSI or take it to a dealer and have him check it for you.
You have installed a new raise valve and moved all the coils to eliminate a bad coil unless by some freak of nature you have 3 bad coils all at once.
You have opened the drop speed valve by 1 turn past the factory preset of 1.5 turns from closed.
You have verified that the controler is functioning properly by not feeding other coils when trying to raise the plow.
You have verified it is full of oil.
You have said that the headgear pushes upword without any issues using the SH2 switch and the plow angleing works fine. These thinds do not take a lot of pressure like lifting the plow so you may either have a malfunctioning Pressure relief valve or a weak pump (although that does not explain fully the reason why it won't power the headgear down). You could try turning the pressure relief valve in one or 2 turns and see if it lifts or at least starts to lift. If it does do not dead head the pump (dead head the pump means do not lift it all the way up the piston stroke). If it works then you will need to have the pressure relief valve set to 3800 PSI with a pressure guage. If it does not work then you are probably looking at a pump replacement or a disassembly to check and make sure a screen isn't plugged or something. Try the pressure relief valve and let me know. Make sure you turn it in and if it doesn't work then return it to the original position. Let me know if this does anything.
I looked up relief valve on the website and it shows a hex nut cap. I don't believe that right. Is it the allen screw above this?
it should be just below the angling valve on the right side of the manifold
This will not turn "in". I tried turning it out, not difference. Under the cap on the front of the pump/motor was a set screw. I turned it in 1-2 turns, no difference.
It gas reached the point that it needs to go to a shop where they can look at the pump pressure. I can only diagnose so much from here and without a guage on the system there is not much more i can help you with. We have verified everything we can externally. Sorry that we couldn't get it for you but now it needs to be looked at on the internal functions. Let me know how you make out.
I was to that point also. Thank you very much for what you have done. I hope to get it in sometime next week. Will let you know how it turns out. Just hoping that the bill plus what I have already laid out doesn't equal a new blade outright.
I don't know what you have invested but a pump is going to run you about 400 so good luck. I have had people come in and want me to install a new mount and a wiring harness and they are shocked to find out that the 2500 dollar plow just cost them within 500 of a new one. Keep me posted.
What did you ever find out about this problem? I was hoping you were going to let me know but since i have heard nothing I just thought I would ask
It turned out to be 2 hoses switched around at the pump.
Damn.. I had not suspected that because there was no mention that anyone had tampered with the hoses. I made a bad assumption on my part. I am very sorry about that. I am glad you got it all straightened out.
vBulletin® v3.7.2, Copyright ©2000-2012, Jelsoft Enterprises Ltd.