Electrical issues and can't seem to figure it out

To begin with it have a 89 Laredo 4.0 i6 automatic trans with 180000 miles I recently purchased. I have lost power to radio,blower motor, all dash lights (gauges still work), and blinkers/hazards but all other lights work. Everything went out at once, they went out a couple days before and came back on before I made it home. This time they never came back on I've checked the fuses and all are good but there's no power going into the fuses of the affected accessories. Has anybody else had this problem??? I can't seem to find schematics for the wiring harness to see if the issue is from before the harness. Any knowledgeable input would be great. Thanks in advance.

Not sure about the 89 specifically. I'd start at the firewall where the engine harness plugs in to the dash harness.

Next I'd check the wires by the battery, the later XJ have a fuse box and other things that tie in to the system near the battery.

Maybe check that first but I'm not sure what's there on the renix. If you've got power at the battery going to the harness I'd look at the firewall plugs.

The firewall is where everything gets tied into the dash and body harness. When I redid my old XJ dash harness , fuse box was damaged from a leaking clutch master cyl. I can say it gets a little fiddley when the connections get lose or the little bolt in the middle is not tightened enough. went back and forth testing things at different stages because I was combing years that probably should work well together.
This is what jumps to mind when I read your question but I can't think of a good reason you'd have a problem where those parts join at the firewall unless somebody or some critter got into them. Which should be unlikely ,...

Probably best to follow the keep it simple rule.




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BTW I might have something for the wiring diagram, I think it is for a MJ 88-89. Not sure if it'll have enough detail for this problem.

Ill look it up tomorrow on my laptop.

Dunno why but the forum phone app hasn't been working tonight. Keeps logging me out. Lost a few posts Because of if.


P.S does the windshield leak?

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The windshield has no leak and I've taken a look where the wiring harness connects through the firewall and found no issues it's an automatic so there's no clutch mater cyl. Everything looks good no corrosion or rust. That's why I feel there may be a chance the issue is before the harness maybe where ever it draws power from. Does it draw straight from the battery or is it from another spot? But the remix motor has no fuse box under the hood, there are relays but only for fuel pump and things like that not for the accessories.

Hard for me to remember the exact details.., but I had a very similar issue that knocked out my radio, blower motor, turn signals, (and maybe something else), and it was a problem ignition switch mounted top-side of the lower steering wheel column that from age deteriorated enough to cause a melt to the connecting brown wire, etc. There are a few members that have made certain mods to this issue, but I can't remember those details either, lol. Perhaps they will chime in. However, a replacement model, and good connections would work.., IF:

If the forum members agree that that is your issue..; then consider the following;

It can be slightly tricky to replace the bad unit with a good one in that the long rod that comes down from the upper positioned Key Lock Switch must be installed correctly into the Ignition Switch. There may be a youtube repair vid that will be helpful. I am on dial-up, so I can't even bother to hunt that down in order to provide you a link, etc. Some repair manuals can be useful too. I had thought I had mine set correctly, but had to fiddle with it again.., errrgh, (*).

Here is a useful thought; Went to the parts store, and obtained a godless commie chinese slave labor replacement, and installed it. No worky. Second one worked, (*). Combined I had to travel 100 miles in order to fix the issue. Had I bought two switches over the counter.., I could either have a spare, lol, or had returned the other unused unit at my convenience, blah, blah, but took the bad one back, and got my money back, (hooray). Thing is, is, that if it is not an OEM part, but after-market.., it comes down to a crap shoot. You might try the stealership, or visit an auto junk yard...

My switch problem happened during blizzard time, and it was a frozen finger issue to deal with a couple of little screws, etc., etc., etc., so now is a good time to dig into it, lol.

The whole ordeal is not too much of a hassle in that you simply remove the lower plastic shroud, then remove 4 bolts in order to lower the steering column down a few inches in which to somewhat easily access the ignition switch.

I've read that could be an issue but what keeps me from replacing it is everything I've read about the actual part is the power from the fuse block goes to it so if I don't have power to the fuses, I would think, the problem is before it. I can't imagine why power would run there and back to the fuse block and then to the accessories you know, I mean I could be wrong this jeep has surprised me before with things lol electrical is not on my list of things I'm good at but I'm running on common sense thinking lol

Ignition switch can do a lot but I would think the hazard lights work regardless.
Our 90s xj did the trick once where it ran but radio, turn signals and accessories did come on but the jeep ran. restated and hasn't done it again.

He is a electrical trouble shooting guide for a 88 MJ book, some kind soul scanned it and put it online for other jeepers, it should be very close to yours. (i'd saved a copy just to keep on hand)
http://www.bteventures.com//mj1988electricalmanual.pdf

Looking at the power distribution 4.0 (page 9), there are fuse links I forgot about. maybe one of them. Fuse link J seem to have most of hazards and lights. You may have no brake lights if this is the one that failed.

But a lot also ties into the ignition.

hopefully this pdf can help a little.

Thank you very much but ya i do have brake, reverse, parking and headlights just nothing with turn signals or hazards but I wouldn't be surprised if that's another issue or even a couple issues stacked lol I bought this jeep a month ago mechanically it seems flawless but electronically it's a nightmare lol

Jeep_xj_life said:

To begin with it have a 89 Laredo 4.0 i6 automatic trans with 180000 miles I recently purchased. I have lost power to radio,blower motor, all dash lights (gauges still work), and blinkers/hazards but all other lights work. Everything went out at once, they went out a couple days before and came back on before I made it home. This time they never came back on I've checked the fuses and all are good but there's no power going into the fuses of the affected accessories. Has anybody else had this problem??? I can't seem to find schematics for the wiring harness to see if the issue is from before the harness. Any knowledgeable input would be great. Thanks in advance.

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Very common Renix wiring problem, 87-90. The problem is the wire (brown wire IIRC) going into and out of the ignition switch to those accessory switchs and the ignition switch itself and the wire connectors are usually toast as well. Not to mention the blower switch and wire. Mine took out the fuse holder too over time. I by passed mine on 2 of my 4 Renix jeeps and ran 10 gauge wires instead of the POS 14 gauge the factory used to a new dash switch, 30 am toggle switch and used a 30 amp breaker. No problems in 10 years as long as I remember to turn off the extra switch LOL.

Jeep_xj_life said:

I've read that could be an issue but what keeps me from replacing it is everything I've read about the actual part is the power from the fuse block goes to it so if I don't have power to the fuses, I would think, the problem is before it. I can't imagine why power would run there and back to the fuse block and then to the accessories you know, I mean I could be wrong this jeep has surprised me before with things lol electrical is not on my list of things I'm good at but I'm running on common sense thinking lol

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If you lost power to the fuse, the wire to that fuse has been toasted and or the contacts for that fuse on the back side aged, fried and broke. That is why I bypassed the fuse box on two of mine with fresh 10 gauge wire (AMC never should have put such huge batch of loads on one 14 gauge wire) and 30 amp resettable breaker. But I had to replace the ignition switch harness connector, the switch, and the wiring and connector to the blower, blower speed switch, and the blower speed resistor pack in the AC box under the passenger side dash, to get rid of the entire problem for good. Oh and the blower motor too LOL.

I never had a fuse link on my Renix beasts go bad, even with a dead short on the O2 heater, but there are fuse links near the battery attached to the power relay that is attached (wire) to the battery. You may have never burned up a fuse link, if you have a dead short, like behind the fuse box or ???? I always melted, literally the fuse, the ignition switch, the blower switch, the wire connectors..... till I got fed up and replaced it all.

Ben lucky on the 89 2wd so far, low mileage....

Jeep_xj_life said:

Thank you very much but ya i do have brake, reverse, parking and headlights just nothing with turn signals or hazards but I wouldn't be surprised if that's another issue or even a couple issues stacked lol I bought this jeep a month ago mechanically it seems flawless but electronically it's a nightmare lol

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You came to right place!!!!!

So why would I have no power to the fuses does the ignition switch run before the fuse? I'm just trying to make sense of it lol

Jeep_xj_life said:

So why would I have no power to the fuses does the ignition switch run before the fuse? I'm just trying to make sense of it lol

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No power to the fuses means your current (sorry for the pun, LOL) problem is indeed between the fuse box and the battery. No doubt about that. You can pull the fire wall side connector from the fuse box by removing the long center bolt holding both halves together. I forget which side of the firewall the bolt access is on.

The bolt is on the engine compartment side I've already pulled it and everything looked as good as new lol i guess it jus to comes down to a lot of time and elbow grease lol no easy answers but whenever I get around to it I'll post the problem thanks anyways but hey if any other ideas come up please let me know

The connections are going to look like new because it was greased up and unopened for almost 30 years . Even my old one looked good here, other side totally different story.

One the bolt is out its two screws to get the inside panel out. It looks like a mess of wires because it is.
You might be able to trace something but it won't look like much.

We are assuming a lot I don't know if the problem is in the fuse box wiring . I kind of think it is but.. That's a hard rats nest to sort, not impossible it looks more daunting than it is. Still I'd check simple stuff first .


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I've decided to just buy a short finder and fix any and all shorts and replace all the fuses and go from there

Glad I searched this. I will attack this asap.
As now all my gauges except speedo (mechanical ftw, ha! ) are inop same with turn/wiper and hvac system. fuses are good and there is power. I bypassed my ign switch a long time ago. I will check the brn wire though.

Looks like my brown wire was spliced to the wht/blk that goes to the cluster. Where is there an ignition powered (keyed) wire to splice into?
Everything that stopped working, started working when I connected power to the wires.