1987 XJ 4.0L No CHARGE!! HELP!!

I have a 1987 Jeep Cherokee Pioneer 4.0L.. Not Charging...I am not new by any means to auto repair but I am thoroughly frustrated about my issue.. Frustrated enough to ask for help...About a month ago I noticed that my Battery Gauge while driving would intermittantly fall from past 13 to 8 and back. This issue got more and more constant until it would not charge at all and totally died about a week ago... I : Replaced the battery= no charge, replaced the alternator=no charge, thought it was a bad alternator from the store took it back, it past the tests at two different auto parts store, but got another one anyway=no charge, replaced all relays= no charge, replaced battery cables both positive and negative,cable coming from alternator to junction box,and the junction box(or whatever that is called)= no charge.. Thought maybe the new battery was bad, got another one. .....Battery is not being charged while driving what so ever.. Seems to me that it may be a voltage regulator issue..I have found conflicting information on the net so i am here to ask......Is the voltage regulator part of the ECM? Or is this for newer models. If it is part of the ECM why are there voltage regulators listed on the part store websites.....If it is not the ECM what in the heck is it??? Help..... I am am getting ready to give up, sell it and buy another one.....If i can't resolve this I will have a 1987 Jeep Cherokee Pioneer for sale.. you can see it at http://home.surewest.net/fearless4x4 or youtube.com/fearless4x4tv.. its the white one.....

You should have the Delco with the internal regulator. Later models are ECM controlled. That is the good news for you. Seems like it has to be in your wiring. Have you checked your voltage output at the alternator, and then compared it to the battery. Have you disconnected the wire at the alternator and the battery and checked that for continuity?

Looking at a '88 wiring diagram, there is a fusible link in the circuit from the alternator to the battery. A red wire with a blue fusible link runs to a big junction point on the starter relay. With the key off, disconnect the red wire from the alternator and check for 12V. This should always be getting juice from the battery. If not, trace to the fusible link.

I have not checked the voltage output on the alternator, I am waiting on my brother to bring me the meter. I have replaced the wire going from the relay to the alternator. I don't see why there would be any continuity issues with this cable but I will know more when I check voltage.

Clean your battery terminals very, very well.

Mine was doing the same thing until I cleaned them.

As for the regulator, yes, it is a Delco as everyone here has said. They are stupidly easy to rebuild and parts for them are usually fairly cheap.....

CAREFULLY check your fusebox and the wiring in that area. i had a renix with the infamous "rotting fuse block issue", it caused a very similar situation. no charge-could not figure out wtf was going on. i found several fuses with little-to-no connection in the box. one of them ran the "charge light" on the dash, along with a few other warning lights. from what i could discern, this had something to do with "turning on" the charging circuit. fixed up the fusebox/wiring with junkyard parts and everything was peachy after that. my clue was that the upshift and gen/alt lights stopped working at the same time i started having charging issues.

Hellbent , which fuse was this ? Tracing down a similar issue in a 87' MJ.

i believe it was a red 10 amp fuse. it was marked as something to do with warning lights. i'll have to go out and look at the mj here in a minute.

Hellbent said:

i believe it was a red 10 amp fuse. it was marked as something to do with warning lights. i'll have to go out and look at the mj here in a minute.

Click to expand...

ok , thanks

Your problem might be with the bulkhead connector at the firewall. Up through 1988(?) they used a connector called the C101, notorious for causing problems. You can take it apart and try to clean it up or just solder the wires together.