Just wondering what the likelyhood is of a guage itself actually going bad. When I originally got my 83 gsl the temp guage worked (never went above 1/4 way up ever) . My problem for the past couple months has been that the guage doesn't work at all! I checked the wire connection to the sending unit (one next to oil pressure sender) and the connection is good (kinda grimy from oil and road buildup over the years from oil changes but pretty sure the connection is good). Could my guage have gone bad? How would I check this? What color is the wire(s) I should look for? I do have an FSM but if someone knows off the top of their head it would be great for some help. Thanks.

 

They can fail sometimes.My oil pressure gauge got corroded pretty bad because the dash vent wasnt hooked up and moist,outside air was blowing on the back of the instrument cluster for an unknown number of years.
You can check the calibration of the stock gauges with a few cents worth of Radio Shack resistors.The FSM tells you what gauge position corresponds to what number of Ohms.
Its more likely that the sender has failed.It has to contend with 200* temps,vibration,expansion and contraction and oil spills.Its pretty cheap to replace and a common offender.....

 

yeah, i would say the sender also. i've had a few go on me.

 

I've had temp and oil gauges themselves go bad. Take the gauge out and look at the fine white wires that are wound around the bi-metal strip. If there is any discoloration, i.e., graying or blackening of the wires. The gauge is usually bad.

 

More likely that your thermostat is now stuck in the open position....Or did you already check that?