1984 Dodge Powerram 50 4D55 engine - instrument and electrical issue

[gard]

Alright, so driving along, I lost the temp gauge, fuel gauge, tachometer, diesel indicator, oil pressure gauge, turn signal function, and the fuel heater all at once. Hazards work, the actual lights and the dash indicators. Tried pulling all the fuses, checking them, putting them back. Toggled all the connections to the back of the instrument panel by pulling them and reconnecting them. Going to pull the dash now and start checking with a voltimeter but wanted to ask the experts for any tips or hints before I got started.

[MainstreaM]

check the traces on the gauge cluster circuit board. Make sure one isn't burned in two.

[gard]

Will do. I took a long look at the wiring diagram last night and it looks like a red/blue wire runs through and is connected to everything I am experiencing issues with. Just a matter of tracking it and testing it down the line to find an issue. Looking at similar posts, I'll keep an eye out for any grounding issues as well.

[pennyman1]

there is a voltage regulator on the back of the cluster that may have failed also.

[gard]

Thanks! Would that just shut down the circuit? Looking at the diagram again I've found a RL red blue running from the gauge cluster that includes the temp gauge, tach, fuel gauge. Has a blue wire connecting it to the diesel indicator, it runs up an over to the 4wd indicator and fuel gauge unit. In the other direction it runs and connects to the oil pressure gauge and out to the oil pressure unit and switch, up from that run it goes to the glow plug control unit, and a final run up to the turn signal unit.

What are my best options? It definitely seems like this circuit is down,
matter of some tedious trouble shooting. Is grounding still a high possibility? Is a single short shutting down the whole cluster?
is it an obvious fuse I missed?

[gard]

Figured it out. The fuse was burnt. Looked fine on visual inspection and had to be the dozenth time I checked the fuses with the multimeter, but it read 12 on the hot side and the 0 on the other. Now, I am crossing my fingers there isn't a bigger issue. I have an auxiliary electric fuel pump because the injector pump wasn't pullling fuel anymore. The previous owner fixed that by adding an electric fuel pump. The part didn't exist anymore when the old one went out a couple weeks ago. The new one may be pulling more power and causing the problem.

[Tdietz82]

Hey did ever figure out your issue with your gauge cluster I am having the same exact issue with my 1984 Power ram 50 diesel. What fuse was it? I seem to have checked the fuses countles times. I have checked the diode and fuse links in the system and still havent figured it out. I am glad i found someone else that has had the same issue.

[gard]

I use a multimeter to check them individually until I found one that wasn’t reading correctly. The fuse looked fine but was defective somehow. Visual inspection just wasn’t enough, had to test each of them.