I've went through two alternators and my jeep still won't charge the battery.

First the alternator died a few months ago, replaced it and no issues since until last week. Alternator died again, took it in and got a new one because of the warranty and it was bad. I'm
About to take in my third one that I though was working to have it tested but wanted some opinions first.

Sometimes I'll be driving and my battery will be reading at around 14v but most of the time the gauge is bottomed out at 9v and the battery isn't being charged. While the gauge was reading 9v I got out and hooked up my multimeter to the battery and it read 11.8v.

TL: DR;

Charging system works intermittently.

Anything that could cause this besides just bad alternators, I'm tired of swapping it out.

 

Check your battery connectors and make sure your charge wire from the alt is hooked to the batt. I left it off my firebird one time while doing an engine swap and I couldnt figure out the problem. Either that or the alternators you are buying are just no good. Some times those parts they sell at autozone and advance arent any good. I went through 3 fuel pumps before going back to OEM once. So dont be surprised if the alts are just bad.

 

All the contacts are clean, just had alternator tested and it's good. I bought some contact cleaner and dielectric grease and am planning to get everything with some grease.

What's next to check? I had ordered an ECU because that's where the voltage regulator is located but then was told that the voltage regulator will not go bad since it is part of the ECU... Is this true or do I need to go pick one up?

 

http://cgi.ebay.com/ebaymotors/Jeep-...-/130537743501

Any idea on a part number or actual name of this harness? I found my charging issue, one of the contacts was nearly busted off and when I bolted it back onto the alt. with a healthy dose of dielectric it broke off. Now I'm hunting down this harness lol

 

Found the answer, that little black block is nothing more than an idiot proofing so you don't mix up wires on the alt. Now that mine is broke, any idea which wire goes to which tab? I need to bypass and would prefer not to guess and check with my electrical system lol

 

new battery? if not perhaps your battery is shorting out. ive had it happen and when its running it was fine but turn it off and try to turn it back on and it wont budge. of course it could happen to a new battery, just less likely probably

 

Gotta love electrical problems. New ends, healthy doses of dielectric grease and countless hours later my alternator is charging again

 

THIS is my issue.

I wrecking yard replaced that stupid little black box three months ago and the problem is back.

When alt don't charge on startup, I get under hood and press finger on it, then it stays working until next time it decides to screw up.


I too need to know which wire goes to which terminal so I can bypass the stupid block of bullschart.

Anyone know?

 

It would be nice if you filled in your Jeep info.


Is this a '98 Grand Cherokee or a Cherokee XJ you're talking about?

 

Good point.....


98 grand Cherokee 4.0

 

I don't have access to GC wiring diagrams or the FSM.


Pacific Coast Manuals.com has the 98 GC FSM. Suggest you download it.


http://www.pacificcoastmanuals.com/j...e_manuals.html

 

Thank you kind sir

 

We also have a Grand Cherokee section in the Forum. You may want to post there.


https://www.cherokeeforum.com/f5/