Hey gang-

I have a '92 SC300. As is common with these, I had the needles fail, so I recently bought a new set and replaced them. I put the dash back in, and they lit up great - much to my relief. However, a couple of the dash bulbs were out, so I pulled out again, and replaced the bulbs then the temp gauge stopped working, though it was lit up and another dash bulb was out. Went back to the dealer and got another dash bulb, and now that everything is back in there, I have full dash lights, nice glowing needles, but now neither my fuel, nor the temperature gauge is working. The lights come on, but no needle movement.

Both worked fine before, but now neither one works. I have disassembled and carefully reassembled the module and can't find any connectors that are disconnected (including the through-dash pins). I double-checked the ribbon cables and the connectors between the boards, and I don't see any issues around the gauges themselves. I don't understand what I could have done that would cause them to stop working, but now I am out the two most important gauges in the dash. The third time out, I measured the resistance on the contacts for the gauges, and they seem to be in spec with what is in my Lexus Shop manual(s).

Any suggestions?

 

Is it possible that the gauges were damaged by the light jostling involved in removing the dash?

Is there a reliable way to test the gauges, besides putting a meter on them? Could I use an external power supply to test the operation of the gauge?