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Hi All, I have just brought a lovely C2 the temp gauge is playing up, sometimes reads fine sometimes goes hard right as far as the needle will go (engine temp is fine) this leads to my other question what works with ignition off IE my electric windows work with key out the fuel gauge even reads with the battery disconnected. Just trying to find out how things should be?
The temp gauge also stays hard right with battery disconnected.
The fuel gauge will drift to a random spot with the power removed; power windows work, by design, with the key off and out....you have an issue with either your temperature gauge or the sending unit on the engine...
You'll have to troubleshoot that - here are some tips.
I imagine when you reconnect the battery after the car has cooled down, the needle will drop back to the bottom? That is what I would expect to happen, it stays where it is until ignition is turned back on with battery connected and then reads the new temperature. The most likely problem would be the sensor going to too low a resistance when warming up. If you read the resistance from the top of the sensor to ground at 180 , it will read somewhere around 110 ohms if correct. You could also be losing the ground where the gauge is attached to the dash cluster. There is a screw that is grounded by a nut when installed that must read ground or the gauge will go hard right.
Some of the things that work with ignition off are:
Pwr windows, headlights, park lights (front and rear), brake lights, dash lights, headlight rollover motors, power antenna, glove box light, courtesy lights, lighter, battery gauge will show discharge if you turn on accessories like headlights or brakes, also the horn, and in a 64 or 65 coupe, the rear blower if the heater fan switch is in the off position and the cable for the rear blower pulled to one of the three speed positions.
Last edited by 65GGvert; Aug 26, 2018 at 07:52 AM.
I imagine when you reconnect the battery after the car has cooled down, the needle will drop back to the bottom? That is what I would expect to happen, it stays where it is until ignition is turned back on with battery connected and then reads the new temperature. The most likely problem would be the sensor going to too low a resistance when warming up. If you read the resistance from the top of the sensor to ground at 180 , it will read somewhere around 110 ohms if correct. You could also be losing the ground where the gauge is attached to the dash cluster. There is a screw that is grounded by a nut when installed that must read ground or the gauge will go hard right.
Some of the things that work with ignition off are:
Pwr windows, headlights, park lights (front and rear), brake lights, dash lights, headlight rollover motors, power antenna, glove box light, courtesy lights, lighter, battery gauge will show discharge if you turn on accessories like headlights or brakes, also the horn, and in a 64 or 65 coupe, the rear blower if the heater fan switch is in the off position and the cable for the rear blower pulled to one of the three speed positions.
I knew there was something else, I sat here running things through my mind and thought "I'm missing something". Thanks.
Thanks guys, great replies and very helpful! Its raining here in the UK today so I will have to have a look tomorrow, is the earthing nut on the temp gauge easy to get to or is it a dash out job?
Thanks guys, great replies and very helpful! Its raining here in the UK today so I will have to have a look tomorrow, is the earthing nut on the temp gauge easy to get to or is it a dash out job?
You can see it and touch it. Don't know about tightening or cleaning. Before I tried, I'd connect a jumper to the threads and connect to a good ground to see if that was the problem.
Try the test suggested above because, if there is a grounding problem the C2 gauge ground is W-A-Y up on a spade lug at the top of the rear of the cluster -- tough to get to without at least pulling the gauge cluster forward...
Try the test suggested above because, if there is a grounding problem the C2 gauge ground is W-A-Y up on a spade lug at the top of the rear of the cluster -- tough to get to without at least pulling the gauge cluster forward...
Can I pull the cluster forward just by removing the 5 or 6 screws and the oil pipe from the oil pressure gauge? How far will it come? If I need to change the gauge can I do it in this pulled forwards position? Thanks again for the help.
I had my fuel gauge in and out of the 63 several times recently by just pulling the cluster forward....I did drop the steering wheel column a bit. It was a PITA but doable - I haven't tried the small gauges on the other side of the cluster....they might be more trouble, I can't say....on a '63 the parking brake handle would have to be dealt with for sure.
The small gauges are generally pretty reliable - I would only put repro gauges in if I had a gun to my head....
I could tell you some stories.... After trying two different repro fuel gauges for my 63 from two different vendors I gave up.
I moved my 63 original face and needle onto an NOS 64 movement and all is well now...
Since I was asked elsewhere I'll share it here....
The first repro 1963 fuel gauge bounced around more than my original gauge that supposedly had the dampening fluid gone - so I sent it back. The lettering and center cone sheen were also way off from original...
The second repro gauge from a highly-recommended, different vendor (who supplies many others) actually mounted crooked in the dash, although the lettering and operation were better. It bugged me enough I finally took it out after a few days and it ALSO went back... The picture below shows the original and this repro gauge exactly as they mounted in the dash and you can see the issue. The repro on the right was noticeably "canted" a few degrees clockwise - it looked worse in the dash with the other gauges. Hence I moved my original face and needle to an NOS 1964 movement supplied by Brian of Corvette Specialties - that fixed me up...
Somebody -- Ernie Willcox ? walked me through how to do it...
The whole point is -- save your originals if you can!
Last edited by Frankie the Fink; Aug 28, 2018 at 11:45 AM.
I've only heard of a couple of instances of any C1/C2 oil gauge leaking behind the dash in my dozen years with Corvettes....the other end -- yeah that's more of a problem..
If you use the right connectors and tighten them properly they seal just fine....
Make that three: The oil line behind the gauge of my '63 developed a crack and would leak a drop now and again. Gauge was fine, tho.
Yes - at worst a drip....doubtful there will be any jets of hot 80 psi oil hosing down the footwell. I think the mechanic in question is guilty of a bit of scare tactic...
Basic Question on Gauges
Did not realize we had so many slow readers in this Forum.
