Charging issue

justjeepin86

justjeepin86

Well-Known Member
Joined
Jul 9, 2005
Location
Winston-Salem, NC
93 Yj, 4.0
The engine on this jeep starts up and runs fantastic. After it runs a couple minutes it starts idling down and then will shut off.

When I check the voltage, it is 14.5 when it's first started. Then it slowly goes down to 12.5 or so and shuts off. It will fire right back up and show 14.5v again. Anther thing to note is the battery gage never shows over 12. That may mean nothing.

I changed the alternator out because the first time I checked it the voltage was low. I didn't check it right after starting with the old alternator.

Any thoughts here? This is strange.
 
mbalbritton said:
You’ve checked the condition of the battery and all grounds and wiring in the charging system?

:popcorn:

I’ll be watching as I have a charging question on my YJ that’s a bit different, but I want to see your answer first.
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Funny you ask. I thought that was the problem when I checked out the cables. I put new ends on them and had no change. Ground is good at the body and block. I have not gone thru the wiring leaving the alt. But, I've also checked voltage at the alt with the same results.
 
I'm no electronics/electrical expert as I've said many times before, so seek confirmation from others. But My thinking is, that if you've checked the battery, ground cables, Changed Alternator and all checks out, then in my head from what I know, that leaves any other wiring or the Computer. I don't think a wiring issue would show up with these symptoms. That seems more go/no go to me. The description of how it starts out fine and dies off, just sounds like computer to my wee little electrical knowledge.


Surprised no one else has chimed in yet.
 
mbalbritton said:
I'm no electronics/electrical expert as I've said many times before, so seek confirmation from others. But My thinking is, that if you've checked the battery, ground cables, Changed Alternator and all checks out, then in my head from what I know, that leaves any other wiring or the Computer. I don't think a wiring issue would show up with these symptoms. That seems more go/no go to me. The description of how it starts out fine and dies off, just sounds like computer to my wee little electrical knowledge.


Surprised no one else has chimed in yet.
Click to expand...
Right, we definitely need some smarter people to chime in. Lol
 
Here is the wiring diagram. Check the ground at both ends and make sure you have 12 volts at the BLK-GRY. Here are some test procedures.
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