I just got the cluster pulled from my '78 and have a pretty straight forward question about the temp gauge. How does it work? Before I pulled the cluster out the tach and temp gauges were not functioning. I got a new tach to put in, so that's covered. However, the temp gauge had no wire hook up on the back and I'm not sure how it functions. Does it work just off the circuit board? Does the sending unit (in the head) just operate the light in the dash? I really would like to retain the stock temp gauge if possible but not sure if I should waste the time and energy trying to see if it'll work upon reinstallation and then having to mess with it if it doesn't. New gauges are pretty inexpensive but ultimately I'd like to keep the stock one. Any insight would be appreciated very much. Thanks in advance.

 

I believe that it runs directly off the circuit board.Check the circuit board right where the big main plug goes into it,sometimes those little brass or copper contacts on the board will come loose right there,and they will move just enough to where they dont make contact with the plug so it would'nt send a signal to that gauge.If you do think it's the gauge,send me a pm,i have an extra factory temp gauge and the factory sender that i can let go of cheap.

 

Appreciate it B.M. I might take you up on that. I went ahead and ordered a new gauge last night along with an oil pressure gauge to replace the clock. Really inexpensive so if the stock gauge ends up working I won't be too upset. When you mention the factory sending unit I'm assuming that operates the warning light if the gauge works off the circuit board?

Do you know how the factory tach works? I removed a broken wire by the distributor (tach filter) and I'm pretty confident that's why it's not working but again, no wire connections on the back of the tach either? What was strange is when I start the car, the tach needle moves when the engine turns over but that was it. I got a nice new Super Tach III to put in anyway but just curious.

 

Cool,getting the new gauge was probably a good way to go anyway,as no telling how accurate these 30+ year old gauges are anymore.There is a company called gaugemarks that can repair or recalibrate them,but i'm sure it would cost quite a bit more than just picking up the aftermarket replacement.As far as the factory sender,it is attached to a wire that runs into the plug that goes into the back of the cluster.

As far as the tach,it would still jump a bit when power hits the circuit board because all the gauges get power from the board.The wire that runs through the tach filter is the signal wire that sends the rpm signal to the circuit board plug harness.If you want to try your factory tach before you replace it,try bypassing the tach filter since it has a broken wire,there should be little spade connectors or something at each end of the wires on the filter,if so just get a piece of like 16 gauge wire and put connectors on each end to connect the wires that did go to the filter.The main reason for those filters was so the rf noise didnt travel into the stereo and make that humming noise,but my filter is unhooked and i have never had a problem with noise.

 

Good info, thanks again. I had heard of gaugemarks before as well but thought the same thing, way too pricey to go that route for something that isn't mandatory for me to keep original. I'm going for funtional, not original.

When I bought this car last summer the wires on the tach filter were broken off right at the solder joint on the ends of the filter. The wire to the distributor was there but I don't know where the wire leading into the cluster even is, it's not there. I was going to try what you explained last summer but didn't know where to connect the wire on the cluster or tach so I didn't attempt it. I do wish I could get all the factory gauges working again but I've pretty much decided to go a more inexpensive route and still have gauges that work. Thanks again for all the insight.

 

When u ordered an oil oressure gauge did u order an original or after market...I couldnt find any for my 81 Camaro so I got one off of a early 80's monte carlo bc they look somewhat the same

 

I ordered an aftermarket oil pressure guage to replace the clock. I don't believe there were factory oil pressure gauges in these cars? Mine is a '78 and didn't have an oil pressure gauge.