I'm having some electrical problems out of my old 88 Ranger. I had to do some repairs and all my lights worked before I repaired the engine harness. Here are the current issues:

1. None of the turn signals work (The Flashers do work)
2. Reverse lights don't work
3. Driver side brake light is ON without the pedal being pushed. (Passenger side brake light works as it should with one exception see below.)
4. If the turn signal is on then the drivers side running light and brake light both do not work.
5. The oil pressure gauge doesn't work.
6. The gas gauge doesn't work when lower than half a tank (This has been this way for years. I just learned that is possibly a broken connection on the fuel sending unit which they don't make anymore. I was told that it could be soldered back to work. I also know of a company that can build me a replacement. I just wanted to try and fix the one I have before spending $75 to $125 on a new one.)

All of the front lights work except the turn signals.

Here's where I got into all of this mess. A squirrel/mouse got under the hood and chewed the alternator harness. I went to work fine but when I was coming back I had smoke come through the dash and under the hood. The alternator harness had grounded to the alternator bracket and melted everything along that harness and into the cab. I spent about 6 hours taking the complete engine harness and cab harness out and removing/replacing the burned pieces of wiring. All of my connections were soldered and heat shrink tubing placed over the connections.

While is was in there I had seen some other "repairs" that must have been done over the years. The headlight switch harness has been over heated and the wire for the head lights needed to be replaced. I didn't replace the plug but I did replace the wire that showed overheating. As I said before the headlights work fine both low and high beam are ok.

The plugs around the steering column also showed signs of overheating and someone had used crimp connectors when rewiring it the first time. I cut all those connections out and soldered them and put heat shrink tubing on all of those.

The instrument cluster had some lights out on it and I replaced them and cleaned up the copper contacts on the printed circuit board. All the lights work now but the oil pressure light doesn't work anymore. The AMP gauge wasn't working because the copper points were burned on the printed circuit. I reconnected them using solder and put liquid electrical tape over the top of the solder to insulate the connection.

When I was removing and installing the cab harness I noticed only one ground wire which was screwed to the back of the dash near my left knee. I cleaned the connection and put electrical grease on it to make sure it had a good ground.

I'm not sure where to start looking to fix this myself. I don't know whether to start at the cluster, the turn signal plug on the column, or the plug under the hood that goes to the rear wiring harness. I'm also suspecting the brake switch but unsure how to test it.

I can't understand where things got messed up because I went wire by wire doing repairs just to make sure that I didn't get anything crossed. Its very frustrating.

Thanks,

James

 

Sounds like one heck of a task ahead of ya. I'd start with the relays under the hood then jump on the alternator and work my way through the cab starting with the fuse panel then the cluster followed by the radio, just to see if someone messed with it. Then follow through to the rear of the car.
Good luck sir

 

Jake you would be surprised with how basic the wiring is. I don't have a radio and only a heater. I don't have any large relays like you would find in a newer ranger. There's not an under the hood fuse block. There is one plug under the hood for the front lights and one for the rear lights. I've cleaned and put dielectric grease in both the plugs. The truck is getting 14.2 volts everywhere so the alternator is charging and it cycles. I think I have a bad ground somewhere. When I removed and went through the cab harness I only had to remove one ground wire which was attached to the dash by a machine screw.

Since the problem is in the rear lights I can rule out the headlight wiring for now. I believe the problem lies in the instrument cluster, the headlight switch plug, or the multi-function switch wiring. I'm not sure if the turn signals and brake light wiring depends on the instrument cluster. I haven't tried using the lights with the cluster removed.

Thanks for your input though. I sort of assumed no one would try to even answer this post.

James

 

Just a quick update. I removed the instrument panel and the brake lights, tail lights, both started working normally. I still don't have turn signals though. When I put the instrument panel back in I get the same problems I originally stated. I think the problem is the instrument cluster. Maybe the wiring harness into the instrument panel is jumping across another circuit? I'll have to find a way to test this.

James

 

I had a Ranger that had a directional problem, sometimes it would work and sometime not.

Finally figured it out, when the steering column was in the up position everything would work, when lower in the driving position they wouldn’t.
Took the steering column apart and found the connector for the Multifunction switch was broken fix it and all was good.

Take a look at the Multifunction Switch inside of the steering column up near the wheel.

 

All the switches are new and I've been through the wiring there and everything is making a good contact in the steering column. I did have to tighten a couple of screws that came loose over time though. Still no turn signals or back up lights when the instrument panel is connected. I still need to check the connections thoroughly at the cluster to make sure something is not jumping current across the connection on the printed circuit board on the back of the cluster.

Thanks Scrambler,

james

 

You said switches, did you replace the Multifunction Switch inside of the steering column ?

Usually when there are problems with parking lights or directionals it s that switch, since all of the exterior light wiring goes through it.

Are all of the directionals out or just the rear ?

Tanking a rear ground but for the lights to work when the cluster is removed doesn't sound right.

 

Yes the Multifunction switch inside the steering column is new.

I'm just having trouble out of the rear lights.

I thought the same thing "a bad ground" but I rechecked the harness and there is only one ground wire which is attached to the dash beside the fuse block. The other grounds are out on the radiator support after the harness attaches to the headlight harness. The rear harness I didn't touch and neither did the damn squirrel that cause this whole mess.

I'm just going about things logically so since with the cluster things don't work that do when its removed my thinking is that the cluster is the problem. I just need a way to test the cluster other that just touching the terminals to something "hot" to see if they work.

I wanted a way to hook up a jumper light to the instrument panel harnesses to see if I could make something like the turn signals work without using the cluster. I just need to know which wires to jump and connect to the test light.

Things are a lot more difficult when your working on something built before the internet.

James

 

Do you still have the old multifunction switch? If so, put it back in and see what happens. If you replaced any other switches, also try swapping them back in, one at a time, to see what happens. If all else fails, put all the old ones back in and try it.

A year or more ago, my son tried replacing the turn signal switch in my 83 Ranger (it quit latching on one side or the other). He got a new one from NAPA, plugged it in, and none of the turn signals worked. He took it back, got another one, and still nothing. They finally carefully compared the old one with the new ones and found there was a grounding strap missing on the new ones. He had to go to another store that carried a different brand before finding one with that strap. The turn signals then worked, he was so proud of himself, and so was I, that he persevered and got the job done :D

 

Just an update. I found the "new" multi function switch to be bad. That has fixed most of the problems. The other problem was a pinched wire on the drivers side rear. The previous owner did a hack job of putting in a trailer light harness and a spot finally rubbed large enough to expose the wire and ground that wire. The only problem left is the turn signals do not work. I believe the turn signal flasher is bad. I'm picking up one of those today and I'll put it in sometime this week since the truck is not my everyday driver.

I got the sending unit rebuilt. If you have an antique that needs rebuilding then send an email to Dan at sendingunitguy@gmail.com. He does a great job and the unit looks factory brand new. The unit tested correctly before it was put in now I just need to put gas in the truck to see how well it works. The tank was nearly empty when it was installed which made it a lot easier to work on.

 

Well I got the Ranger back from the school. They replaced the multifunction switch. They were able to get the brake lights working and the taillights going but I still don't have any turn signals. I guess this repair is above their skill level. The emergency flashers work. I replaced the flasher in the front of the fuse box and that didn't fix it. When I turn the turn signals on I get nothing not even the indicators light up on the dash.

My headlights will turn themselves off if turned on for awhile. This wasn't a good surprise because I picked the truck up at night to get get it home.

None of my gauges work. I ordered another instrument cluster to install in place of the bad one.

Does anyone have any suggestions on where to go from here?

I don't want to put the cluster I just bought in and burn it up. It took too long to find it and cost to much to tear it up connecting it to the harness.

I plan on wiring in a new headlight harness and installing a new headlight switch. I'm also going to install a new turn signal harness. They both show signs of getting hot.

Any diagnostic procedure anyone can think of would be greatly appreciated for any of this.