84 gmc battery issues

[zlssefi]

i have an issue with my 84 gmc k2500. The battery seems to randomly go dead. I have checked the whole system for draws and when i couldnt find any draws i put a battery cutoff switch on the ground side. Even after i did this the battery still goes dead randomly. Any ideas what may be the cause here? im stumped.

thanks in advance!

[Tileman]

First off welcome aboard. My guess is there is a bad cell in the battery and it not holding a charge or second the alt is on the way out. Have the battery load tested.

[Hoofty]

I have to agree with Tileman, sounds like a dead cell in that battery. Take it to one of those parts places that will load test it for free.

[wyldman]

Dead cell will not usually cause a dead battery. A shorted cell or plate will. Either way, if you have disconnected the battery and it still dies, it's a battery :D

Check the case to make sure it's not filthy. Battery acid and dirt on the outside of the battery will create a path to ground and cause a dead battery over time.

[Tileman]

Chris when I said dead cell was meaning shorted out (plates have fallen apart and now cell shorted out and will not retain charge.)

As you said either way the battery sounds like toast. :D

[Hoofty]

My fault.....I just used the term "dead" meaning a bad cell.

[2COR517]

Dead cell will not usually cause a dead battery. A shorted cell or plate will. Either way, if you have disconnected the battery and it still dies, it's a battery :D

Check the case to make sure it's not filthy. Battery acid and dirt on the outside of the battery will create a path to ground and cause a dead battery over time.

That's exactly what I was going to say;)

[zlssefi]

The original battery had a bad cell in it and it has been replaced. The truck has the same issues even with a brand new battery in it, when load tested the new battery checks out a.o.k.

[2COR517]

If the battery has been completely isolated from the rest of the electrical system and still goes dead in a matter of days, the battery is bad. Is the battery clean as Chris suggested?

I presume the alternator is charging correctly, correct?

[snowjoker]

When you disconnect and reconnect the battery, do you get a spark like there is a drain on it somewhere ? Your truck is extremely easy to diagnose and work on. If the Battery is good and the alternator is charging you should not have any problems....Put a volt meter on the battery while the engine is running and report the voltage back here..

[zlssefi]

There is no spark when i disconnect and reconnect the battery. I even put a test light in the positive circuit to show when there would be a draw and there was nothing. The battery is brand new, no leaks no dirt no corrosion. The alternator charges 13.6 at idle and 14.6 at high idle.

[stargazer]

There is no spark when i disconnect and reconnect the battery. I even put a test light in the positive circuit to show when there would be a draw and there was nothing. The battery is brand new, no leaks no dirt no corrosion. The alternator charges 13.6 at idle and 14.6 at high idle.

Don't forget wyldman's advice to isolate the battery. I had the same thing with a new truck. I finally took out both batteries and put them on milk crates. Just disconnecting them should be enough, I was going overboard.) In a day or so one still had a good charge and one didn't. The bad one was killing the good one.

[snowjoker]

Try another battery............

[wyldman]

You should not get much of a spark when connecting the battery on that truck, as there is little to no parasitic drain. That truck has no computers or fancy electronics to draw off the battery.

If you have an aftermarket stereo, or alarm, they could be draining the battery. They won't always show up when checking.

If the battery goes dead with the battery disconnected, then it's the battery. Current cannot flow thru the truck if it's not connected.

When this happens, is the truck totally dead ? or just low enough it wont crank over ? If it's totally dead, something must be staying on and draining it down. If it's just a low battery, then you may have a weak alternator, or some other issue. Check the alternator plug, and replace it if suspect, as they are notorious for bad connecions. This will cause intermittant charging.

[Random Services]

Please do not take this the wrong way but is your disconnect switch installed correctly?
Wyldman is right if the battery is clean and disconnected it has no path of continuity. I have however seen people bolt those big red switches to the radiator support using the termial bolts to mount them. This basicly ties both sides of the switch togther through the support frame.
Make sure the switch is installed correctly and completely disconect battery to seperate it from the vehicle. if it still goes bad its a defective battery. If not the check alternator. if you still have problems then you have the pleasure of chasing down an intermittent parisitic load. every tech dream job. :D

[chuckret]

I had this problem in a car once. Corrosion got to the fuse block and sometimes wires would touch (short) to ground when the car was parked.
I had to replace the fuse block. I also had another car shorted out at the firewall connection! Your truck ain't new - it's seen a lot of years sittin' 'round.
Good Luck