Fuel and Temp Gauge don't work

[Big DB]

My '82 DLX Truck has been sitting for close to 20 years. I am in the process of getting it back in commission. The fuel gauge and the temp gauge are not working. Any feed back on where there might be a rusted ground connection on those or other thoughts. The fuse is good.

 

[69FJ-2.4LTRTDIESEL]

Go to the sending unit wiring at the tank and ground the signal wire, see if the gage responds to full. Sending units work on the amount of resistance coming back from the sending unit. A lot of times the pick up terminals on the sending unit are nor contacting the PC board strips on the sending unit. Treat the temp sending unit the same way. If both react look for the main grounding points at the engine compartment and fuse box. Clip your test light on positive and check each ground with test light. Hope that helps

 

[jimmyjim]

there is a main connector block located on the underside of the steering collumb that may have leads that go to the indicator panel. wiggle it and see if that helps. its really tricky to get to the back of the panel itself to see if there is a bad connection there though. because the fule tank leads run from under the bed, but the temp gauge is on the engine, it may not be the senders that are faulty. but check to see if the temp lead has come loose from the sender. also pull the lead loose, and check the resistance from there to ground, while a helper keeps an eye on the dash indicator. this sounds like open circuits, and two seperate problems.
that said, the previous reply is a very good one. and auto electric problems are often the hardest to troubleshoot or fix.
unfortunately, toyotas color coded wire diagrams in chiltons and haynes are not at all reliable. and they did some weird splicing moves to save on the lengths of wire.