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got an electrical grimlen

DesertRatRon

DesertRatRon

NAXJA Forum User
Location
Apple Valley California
I have an electrical grimlan so where in my 1988 xj im stumped i cant find whats causing my battery not able to charge from the alternator I've gone through 3 of them cause my smitty built bumper kept eating the side of them but when ever i put it in gear running the battery gage dumps to zero i found so rogue wires but that wasnt ir i was told it was short some place but i cant seem to find it any help is appreciated
 
Are your motor mounts tired? I ruined one alternator by using a non-stock bolt on the tow hook/bumper bracket. The motor mounts let the alternator hit that bolt on a regular basis... and the rest is history.
 
You have to make sure you have power (12V/battery voltage) yellow wire to the I/F connection (marked I/F or just I or just F) on your alternator. And you have to make sure the *fusible link* on the red wire isn't bad. There are Delco alternators with different hookup configurations, they are marked on the back, hard to see. The volt gauge wire is tan and hooks up to the L connection.

Other than that your block ground from the battery has to be good.

Have you checked at the battery plus and seen what kind of voltage you are charging, if any?

Only other thing I can think of is you have a bad (way low resistance) solenoid in your auto transmission that is sucking down the power and fooling your gauge some. I've seen the volt meter dip way down with a bad very low resistance auto trans solenoid (in the OBD models, not sure if Renix is the same or not).
 
There is a ground wire in between your battery and the PCU unit its in two pieces.. They corrode inside.....I know my 91xj never would charge until I pulled that apart and cleaned with light sand paper, and added very small amount of dielectric....
 
Last edited:
8Mud said:
You have to make sure you have power (12V/battery voltage) yellow wire to the I/F connection (marked I/F or just I or just F) on your alternator. And you have to make sure the *fusible link* on the red wire isn't bad. There are Delco alternators with different hookup configurations, they are marked on the back, hard to see. The volt gauge wire is tan and hooks up to the L connection.

Other than that your block ground from the battery has to be good.

Have you checked at the battery plus and seen what kind of voltage you are charging, if any?

Only other thing I can think of is you have a bad (way low resistance) solenoid in your auto transmission that is sucking down the power and fooling your gauge some. I've seen the volt meter dip way down with a bad very low resistance auto trans solenoid (in the OBD models, not sure if Renix is the same or not).
Click to expand...

Awesome thanks and i checked the battery with the multi meter and its only pushing 12.9 when its running
 
Hypoid said:
Are your motor mounts tired? I ruined one alternator by using a non-stock bolt on the tow hook/bumper bracket. The motor mounts let the alternator hit that bolt on a regular basis... and the rest is history.
Click to expand...

My motor mounts already went out on me a while back and when it went it went badly and the whole passenger side of my engine compartment was a mess but no a bolt that was supplied with my sb bumper was too long and would rub the side of the alternator and rip it up so instead of cutting it like planned i was able to just flip it around
 
DesertRatRon said:
Awesome thanks and i checked the battery with the multi meter and its only pushing 12.9 when its running
Click to expand...
That right there says you are running on the battery. Time to sort out the wiring.
 
Start with the connections...
 
Start with seeing how much your alternator is putting out, one lead of meter on negative post of battery and the other on alternator output. Should be about 13.5 volts. That tells you if the alternator is doing it's job and the output just isn't making it to the battery. Cable, connection etc. Use a voltage drop test on your cable and connections at that point. This will tell you how much voltage is being consumed pushing electrons through a high resistance such as corrosion. If the alternator is not putting out enough then the alternator and its inputs should be looked at. As previously mentioned, the alternator receives voltage in order to create voltage. Check that wire (don't have diagram in front of me to tell you which one) to make sure it has 12 volts. If it doesn't, you have to chase that back. There are no magic bullet fixes, just good solid diagnosis.
 
Have you been through any mud puddles lately? The brushes sometimes get covered in muddy water that dries into a crust.

Coolant spewed into an alternator can short it out internally. Coolant is much worse than water is. Sometimes you can wash it out with hot water, sometimes it fries the regulator or the diode pack.

A crispy ignition switch or a corroded splice can mess with the juice going into the alternator on the yellow wire. Usually the splice, if the ignition switch is messing up you get all sorts of issues, like a bad miss from a weak ignition coil/module.
 
8Mud said:
Have you been through any mud puddles lately? The brushes sometimes get covered in muddy water that dries into a crust.

Coolant spewed into an alterntogether short it out internally. Coolant is much worse than water is. Sometimes you can wash it out with hot water, sometimes it fries the regulator or the diode pack.

A crispy ignition switch or a corroded splice can mess with the juice going into the alternator on the yellow wire. Usually the splice, if the ignition switch is messing up you get all sorts of issues, like a bad miss from a weak ignition coil/module.
Click to expand...

I dont do much mudding but no i was doing my oil pan gasket and rear main the power wire to the starter arched out didnt think out anything of it really got everything back together put oil in ran it then my gauge was around the 9 mark for my power put it in gear then the the gauge dropped to zero im totally stumped
 
So i went and tickered on the jeep today as much as i could before wanting to just turn it to a trailer i found a wire all chewed up tucked away behind my oil filter after following it it led me to the starter so i just changed out the whole wire but that didnt seem to change anything
 
I hooked up the multi meter and started testing wires and im only get 12.0 from the battery and the altenator im still not sure why the alternator isnt charging the battery my connections are fine im thinking about just un hooking my lights,radio and fan to see anything there
 
DesertRatRon said:
I have an electrical grimlan so where in my 1988 xj im stumped i cant find whats causing my battery not able to charge from the alternator I've gone through 3 of them cause my smitty built bumper kept eating the side of them but when ever i put it in gear running the battery gage dumps to zero i found so rogue wires but that wasnt ir i was told it was short some place but i cant seem to find it any help is appreciated
Click to expand...

Gone through 3 whats? Batteries or alternators? Have you fixed the physical problem yet?

The short of the +12 V to the starter, large one, to ground could have fried some sensor ground wires, like the O2 sensor. I would charge the battery to a full charge, and then pull all the connections at the starter relay, near the battery,

http://www.naxja.org/forum/showthread.php?t=1073495&page=2

then connect one wire at a time to the large post (connect the + battery wire first to that post) and look for a voltage drop at the battery. Or just jump one hot wire at a time to the battery + with a 10 Gauge (apx) jumper wire (might add a 30 amp slow blow fuse to the jumper wire).

That would test the + wires one at a time. The ground wires are mostly at the oil dip stick and they can always be a problem just making good continuity to the battery ground on Renix jeeps. You could also disconnect the battery and test each + wire for continuity to ground using Ohms scale and if you find one that is say 10 ohms or less, it is likely shorted ground.

Could be missing a ground at the alternator, but I doubt that from I read so far. In fact it does not sound like a ground problem yet (might be later once you fix the power drain issue!!!)
 
Last edited:
Ecomike said:
Gone through 3 whats? Batteries or alternators? Have you fixed the physical problem yet?

The short of the +12 V to the starter, large one, to ground could have fried some sensor ground wires, like the O2 sensor. I would charge the battery to a full charge, and then pull all the connections at the starter relay, near the battery,

http://www.naxja.org/forum/showthread.php?t=1073495&page=2

then connect one wire at a time to the large post (connect the + battery wire first to that post) and look for a voltage drop at the battery. Or just jump one hot wire at a time to the battery + with a 10 Gauge (apx) jumper wire (might add a 30 amp slow blow fuse to the jumper wire).

That would test the + wires one at a time. The ground wires are mostly at the oil dip stick and they can always be a problem just making good continuity to the battery ground on Renix jeeps. You could also disconnect the battery and test each + wire for continuity to ground using Ohms scale and if you find one that is say 10 ohms or less, it is likely shorted ground.

Could be missing a ground at the alternator, but I doubt that from I read so far. In fact it does not sound like a ground problem yet (might be later once you fix the power drain issue!!!)
Click to expand...

Thanks i think i found the drain problem started the jeep ran everything from my hid lights to the head lights to the electric fan and my radio the gauge stayed at the line before the red zone for the battery took it around the block a couple times and did just fine so ill go through and test everything again
 
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