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1990 BJ - intermittent electrical issues

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No history on wagon as it came from at least two years in impound. Figured out the clutch was gone. Installed new clutch and it was working great. Never had any starting issues.


(1)Starting to get a little smug about my cheap car and actually did a little vacuuming. Go to start it and nothing. Wasn't too worried, cranked the wheel, pushed a little harder on clutch, and she started fine. Didn't think twice.


(2)Out Sunday afternoon and would not start after parking for 30 min. Tried for several minutes with no luck. Gave up and went to a movie. After 3 hours at -20, tried again with no luck. Showed up 12 hours later and she fired right up and I drove home.


(3)So 20 min later I was driving straight home to go over battery connections and grounds. Cruising along in 4th and she dies on me a mile from the house. Noted symptoms and had to get a tow.


Once secure in the garage, I went through the grounds and the connections at the main fuse box (MFB). Also found no bad fuses in MFB or Fuse/Relay Box (FRB). I did find a ground that was finger tight that I had missed after clutch install. Tightened it up and tried for a start. Weak crank so I left it on the charger while I swapped the PS pump. But kinda thought I solved my problem at that point.


After PS pump install and a bit of charger time, she started great! I'm a little slow but not a fool so I went to turn it over several times over the next day. No problems, thought I was good-to-go.


(4)Left the homestead with confidence today and got stranded on the other side of town. Was running fine but after I shut down, no joy.


Generally, it seems to be an issue in an early branch, maybe from the MFB. Battery seems to be in good shape, since it cranked fine after sitting in occurrence 2. For the same reason, I don't have any reason to suspect starter. Also attempted a jump, which changed nothing. Seems like a poor connection somewhere or a big relay I don't know about.


Now that it's happened a few times, I'm pretty familiar with the symptoms. When it's down, I have no power anywhere in the vehicle with 5 exceptions, which were consistent for each of the above occurrences.


power: parking lights (switch on steering column)

hazards (lights flash outside and on instrument cluster)

power locks

auto seat belts (came forward and then didn't come back up)

ignition chime (when key is inserted and door is open)


no power: everything else


So it appears all the emergency items above are probably still working by design. I just need to figure out where the circuit branch is that is failing me. Working on acquiring the FSM but have had a look at my Haynes and have found fuses 22 and 23 on MFB and fuses 5 and 11 on FRB. (Not sure but don't think there is an "always hot" feed to the FRB.)


Anyone have an idea where the above items are getting their power? This may be obvious with the MFB pulled out but my MFB is on the other side of town.


Thanks for any ideas and I will begin the perusal of the FSM!



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i can try to help ya. Im ASE certified, working in a shop, and i have Mitchell available 24/7. Im studying the wiring schematic to answer your questions and although wiring is a strong suit for me, simply discussing it online isn't that easy. Anyways,

The fuse/relay box, (under the dash) gets always hot power feed from the fuse 22 and 23 from the main fuse box (under the hood). Fuse 23 supplies the load power for the tail/illum relay and leaves for the parking light switch. fuse 22 runs thru the under dash box and supplies power to the hazard switch, shift lock control and antenna motor.

The seatbelts get thier power from under the hood fuse box thru a fusible link. That also supplies constant "hot" power to the under dash fuse box which goes thru fuse 11 which should be the left front door lock switch, aka power door locks AND power window circuit breaker. Chime?. didn't look that far. Sorry.

Have you ACTUALLY had the battery tested, just to make sure?.. Wouldn't hurt. Its usually free anyways.......

Other than that, sounds pretty complicated.. too bad you didn't live in northern indiana....

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Update: after letting car sit 24 hours and cool down, it fired right up, again. Ditto after I got it home last night: would not restart after shutdown but fired up fine this am.


Thanks for taking a look mnstrmech. There does seem to be a power distribution issue on circuits other than fuses 22 and 23 that is heat related. I just need to determine how the power gets there.


Haven't had the battery tested but I did try a jump and a battery swap with the same results.


Considered a short in the alternator. When it wouldn't start last night, it measured 12Mohm so it looked to be a short. Measured today now that things are working and I'm not finding any continuity. I'm thinking that once the alternator warms up, it will short when static (not running), which is why it won't start when warm. After it cools down, the short opens again. Does that sound like a reasonable explanation?

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Fusible Link


Finally got stuck in town as it wouldn't restart after cooling down. From there it was relatively simple: I just went through swapping slow-blow fuses and pulling/reinstalling fusible link. Easier to find when it wasn't working!


What I have now is bent and kinked spade receptacles crimped to some 10ga wire. Works most of the time but I will try to replace with original.


Thanks mnstrmech!

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