taylorpaul56

I recently acquired a 1985 Cherokee Pioneer from a family member. It has the 2.5 liter engine with automatic transmission and 4 wheel drive. It has been 2 or 3 years since it has run. It seems to have some electrical problems. The starter had a dead short and the ignition module seems to have gotten hot (the tar in the back is mostly melted away and it tested bad at Auto Zone). I do not have the new starter or the ignition module installed at this time because I feel like there is a further electrical problem. If I put a volt meter on the battery I get about 12 volts, if I turn the ignition key to the ON position or to the Accessory position the volt meter drops to about 3 volts. I feel like there is a short somewhere. Any help would be truly appreciated. Sorry to be so wordy.

Bustedback

Your battery is junk. Dropping to 3 volts with a minimal load should be the first clue. How old is the battery?

taylorpaul56

Sorry for the typo. The voltage drops to 10.3 volts. The battery is about 2 months old and was operating fine in another car. Since I posted earlier I noticed that the rear wiper was turned on. The rear wiper doesn't seem to try to run. With the switch off, I don't get the voltage drop. The radio has a clock screen and it goes off if I turn on the rear wiper. Is the wiper motor most likely the problem or the wiring where it passes from the body to the liftgate? Thanks for your help.

BlueRidgeMark

Probably a frozen motor, but you won't know until you test it. If you can disconnect the motor (I don't know how it's connected on that year), try it that way. If it's fine while disconnected, the problem is the motor. If it's still a problem, you have some wiring to trace.

Hapdad

Hmm I would check your grounds. loose or high resistance grounds cause all kinds of issues. A drop of 3 volts when going to the on position with the key is a clue to this. (cranking might be another story) Get out your volt meter and check voltage at the battery from negative to positive with key off. turn key on and check voltage. See how much drop you have. then place one test lead on the negative post of the battery and the other at various points on the body and engine that should have good ground. any reading on your meter will indicate resistance to ground. A tenth of a volt maybe not so big a deal. You are looking for a where your 3 volts drop is going. A new battery should hold up even a huge draw for a short time if fully charged. So a dead short of that size should be really heating up a wire. This is why I would suspect a ground. If you find your voltage drop then check the grounds between where you found it and the battery.
hapdad