Gauge cluster ground???

[jlkuehl]

The gas gauge in my 92 Ranger never has showed anything at all, the needle never has moved. First thing I checked was the sender, pulled the bed off, and removed it, on the bench, the resistance changes smoothly from empty to full and back. So, I figure the sender is good, and inspect the wiring to it, and didn't see anything out of the ordinary. I pulled the cluster so I could swap in an exploder cluster, and checked the resistance there, and it seems to be getting signal to the cluster. I put everything back together, and figured when I got the money I would buy a sender, thinking maybe it is breaking down when the truck electrical system powers it up. Now, today something interesting happened, which makes me think it's ground related. When I turned the ignition on, without starting the engine, the gas gauge moved slowly up to between 1/2 and 3/4 tank. It dropped back to empty when I started the engine. As I pulled out onto the highway, my oil pressure gauge dropped way past the bottom L of the gauge, and the gas gauge started working again. All of a sudden, my oil pressure gauge swung up to the "High" position, and my gas gauge showed way over full. Just as suddenly, the oil pressure gauge dropped back to normal, and the gas gauge quit working again. So, I figure the cluster must have a bad ground. Now my question is, where does the cluster get it's ground from? I'm assuming the oil pressure and fuel gauge share a common ground at some point, and it's loose or corroded at it's connection to the body.

 

[richard89]

Just finished up with a similar problem with ground in a 93 dash assy I installed in my 89. In the Tech section ther is a great diagram of the connector pinout for a 93. I think that the 92 is similar. Also check the printed circuit onthe cluster and trace out the gauge grounds. Good luck.

 

[jlkuehl]

Others may correct me here, but I believe the wiring change occurred mid-92. Mine is an early 92, so is different than the 93. Everything works, except the fuel gauge, and it didn't work in the old cluster. Last night I went out and cleaned all the grounds under the hood, still no fuel gauge. Took the truck out today, and it didn't do anything abnormal, so I still think there is either a ground wire somewhere that has broken or corroded. It kinda reminds me of my 78 chebbie I had that lost all it's tail lights due to a single little wire broken under the dash.

 

[strvger]

could it be broken where it comes out of the tank? just a thought.

 

[jlkuehl]

I I had thought of that, the wiring looks to be pretty decent, and a continuity test shows good. I wonder why though that it would work when the engine isn't running, but show 1/4 tank all the time when it is running....Trying to think of anything that would be grounded when the engine is off, but not grounded with the engine running. At first I thought it might find a ground through the oil pressure switch, but that only grounds when the engine is running. It's got me baffled, there has got to be something causing this. I know if it ain't broke don't fix it, and if it is broke, blame it on someone else, but what do you do when it ain't broke and still don't work??

 

[jlkuehl]

OK, today, I put new shocks on the rear of the Ranger, now my oil pressure gauge refuses to move at all, and the gas gauge reads about 3/4 tank. So, now I guess if I want both to work, I have to put one old shock back on, and have one new one on as well. So, all lame attempts at humor aside, I'm starting to wonder if I just got a flaky cluster, since the old one's oil pressure gauge never gave a problem, but the gas gauge never worked. I used the pin-out found elsewhere and compared my new used cluster to the original one, and didn't find any differences. I also put the VOM on my new cluster and couldn't find anything that was shorted together that seemed strange. So, any clues where I can look?

 

[jlkuehl]

Well, today I pulled the cluster back out, checked every bit of the flexible circuit board for shorts, tested all the grounds, and checked the sender unit wire to the sender. My tester shows all grounds have less than 3 ohms resistance, the sender wire shows about 70 ohms or so. Still, the fuel gauge reads with the ignition on, engine NOT running, then drops to about 1/4 tank once I start the engine and stays there while it's running. I'm lost, if I can't figure it out soon, I'm going to just say the poor old truck just can't have a gas gauge.


Just a quick thought, could the ignition switch itself have something to do with this problem?

 

[strvger]

is the new cluster the same year as your truck? could be a computer problem trying to operate dissimilar instruments. just a thought.

 

[jlkuehl]

No, the cluster is from an 89 Explorer. From what i've heard, it should be the same as the 92 ranger before the 93 wiring change. I hope that's not the case (about the computer), but it would make sense. I sat in the truck today and turned the ignition on, and the gas gauge slowly moved to a little over 1/2 tank. Once I started the engine, it quickly dropped back to 1/4 tank. I found another ground point behind the DS kick panel, and it was all corroded and gnarly looking, so I took it apart, re-stripped the wires, cleaned the terminal end and where it mounts, and put the whole thing back together. My amp gauge reads higher than it did before, but still no gas gauge when the engine is running.

 

[jlkuehl]

Ok, now I'm totally baffled. I haven't cut, spliced, pasted, soldered, folded, spindled or mutilated any wires, I haven't changed any parts, but now my gas gauge works and is actually fairly accurate! The temp gauge gets all the way up to the "N" of normal (higher than it has EVER read), and the volt gauge reads a little higher than it used to. However, the oil pressure gauge points all the way to the left (at the 18 on the volt gauge). Now, I'm starting to wonder if the oil pressure switch has been giving out and somehow causing the problem. There has to be something common shared across the gauges that I'm not seeing. So, now I need to troubleshoot the oil pressure gauge, and hopefully it's just a bad switch. If the switch did go bad, shouldn't the check engine light come on, though?

 

[blake]

I have what I think is a OP switch going bad and it does not seem to effect my check engine light so maybe not ... My gauge jumps from normal to way low on oil pressure ... Im assuming its the oil pressure switch but cant seem to find the switch or anywhere online where it is pictured or explained for a 92 ranger.... ? any ideas? you seem to be a bit of a 92 ranger ops guru

 

[Ronv]

I do not know if there is a ,"voltage-regulator" for the Ranger instruments but I do know some vehicles have them. Just an idea.

RonV

 

[martin]

There used to be a 5v IVR in the older clusters. There used to be a thread about IVR related issues but I don't know where it is. It might have been before the last server crash.

 

[redxlt]

My 86 ranger has horrible issues with the gauges. I was told that the "regulator " may be going bad. All my gauges read high . I have tried everything but nothing works . So, I bought a new gauge cluster (new to me). and a regulator . will keep you posted on my progress or success .