Instrument Cluster Issue (1 Viewer)

[bhend101]

The Oil Pressure and Water Temp quit working on me. (at the same time)
I have check fuses and have reseated plugs and can not get them to work.
I have not changed sending units
I did remove the cluster unit and change Bulbs, they both worked after this.
Not sure where else to look, Aany advice on where to look?

 

[diesellibrarian]

Grounds? Follow the ground wire(s) (I think it's a brown wire) to the common ground likely on the driver's side A-pillar under the dash. A number of circuits ground at this location. If you can trace the wires between the gauge and the ground point, you may find a burnt or broken wire somewhere.

 

[2mbb]

Oil Pressure and water temperature have different ground. Water temp is grounded at the sender. Oil pressure has grounds at the sender and at the bottom of the left A pillar.

Water temperature, FUEL gauge and the high beam light all seem to share the same ground. So if your water and fuel are acting up, check your high beam indicator, then check that ground.

 

[bhend101]

Oil Pressure and water temperature have different ground. Water temp is grounded at the sender. Oil pressure has grounds at the sender and at the bottom of the left A pillar.

Water temperature, FUEL gauge and the high beam light all seem to share the same ground. So if your water and fuel are acting up, check your high beam indicator, then check that ground.

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Thank you for sharing diagrams. I will do some ground checking. The High Beam, Fuel, Voltage, Brake, and Seatbelt all work. Just those two that are down.
I am wondering if when I pulled the cluster out I shorted those two boards out somehow?

 

[2mbb]

I'm pretty sure there is an "on-board" voltage regulator that is not shown in the wiring schematics. I think it provides constant voltage supply for the water temp and fuel gauge. I'm not sure about the oil pressure though. You might do a search for more information.

 

[midknightc3]

Are your gauges pegged at their physical max, or bottomed out? Pegged is usually the ground. I've had my fuel and temp max out, which scarred the crap out of me. Found a loose ground wire that was common between them on the back of the gauge cluster. Recently my temp gauge has been jumping from pegged on max to bottomed out, haven't had a chance to pull the gauge cluster to see what's going on with mine.

 

[bhend101]

Are your gauges pegged at their physical max, or bottomed out? Pegged is usually the ground. I've had my fuel and temp max out, which scarred the crap out of me. Found a loose ground wire that was common between them on the back of the gauge cluster. Recently my temp gauge has been jumping from pegged on max to bottomed out, haven't had a chance to pull the gauge cluster to see what's going on with mine.

They are bottomed out.
I have only removed the cluster and reset the wire harness, is it worth taking these Further apart and re assembling? See if there is anything more internal that is loose?

 

[midknightc3]

I'm assuming bottomed out is a problem with switched power from the ignition? I'm gathering this since when we turn the ignition off, all gauges bottom out. However, it's obviously something closer to the gauges themselves since yours is two gauges and mine is only one. Looking at the wiring diagram, they all share a common power source through the 7.5A fuse, so if the issue were with that common power the whole cluster would be bottomed out. Poor grounding on the gauge seems to cause the related gauges to max out, so the opposite issue being power and not ground also makes sense. I would back trace your power wires (I think it should be a yellow, based upon my wiring diagram???) and see if you can find something loose anywhere along the way, but once you get to something common to other gauges you've likely gone too far and missed the fault. Hopefully in coming days I can pull my gauge cluster and see if anything stands out on mine as well, though I think I have multiple problems happening at once.

Clark

 

[midknightc3]

I'm reminded of Occams razor. Had some time before I work today and pulled the gauge cluster out. Pulled the whole gauge assembly out of the dash, pulled the cluster out of the greater assembly, removed the plug from the cluster and cleaned all the contacts, found nothing wrong. Put it all back together and pulled the trim/kick pannel off the A pillar under the fuse pannel looking for loose wires/ground. Again, found nothing. Then, and only then, did I pop the hood and do the easy thing...look at the bloody sending unit! Wire from the sending unit to the dash was too long and had worked it's way down onto the exhaust manifold. Quick cut and splice and my problem should be solved (I'll find out when I go to work, not worth running the Goat for 15min to warm up just to check the gauge).

In your case with it being two gauges, I would trace the wires back and see where they go into the same wiring harness. I'd put good money on the theory that something has pinched/warn through that common wire bundle, possibly behind the engine or maybe where the harness goes through the firewall? At this point I would be pretty confident your issue isn't within the gauge cluster...

Clark

 

[bhend101]

Thanks for the info! The PO made a mess of the wiring, I have been spending time cleaning it up. I will continue to look for the issue as I clean up wiring.

 

[midknightc3]

Well bad news to report, driving to work today my gauge still doesn't work. I still don't think it is a problem with the gauge itself, but I'll have to keep looking. Temp sending unit might be my next step anyway.