Topic: Explain this to me..........
in Forum: C3 Electrical, Body and Interior
Ok so Last night was the maiden drive of the year. Over the winter I replaced my fuel gauge ( no more bounce) and also replaced the printed circuit board. Everything was working fine as I headed down the road last night. After I parked the car and it sat for a few hours I got back in to head home and noticed that I had lost power to my clock, oil pressure gauge, voltmeter and ac blower. Needless to say I drove home without event. When I pulled into my garage and turned the car off, my tach needle pegged out. I restarted the car and the small gauges and blower all started working again, yet the tach remains pegged.
Any thoughts as to what the heck is going on here???
Rook
Lifetime MemberModerator
That's the first place I would look for a problem, Dan.
It's possible the circuit board(s) are a little loose in the sockets, or possibly the panel is loosing it's ground.The tach pegging may or may NOT be related, but my guess is that it is. A pegged tach can also be a faulty tach filter, located in the wire(usually a white wire) close to the distributor.
Did you replace the circuit board for the tach/speedo also, or just the one for the center gauge cluster?
Joel Adams
C3VR Lifetime Member #56 
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I had the instrument panel out and tested everything 2 and 3 times, I ran the motor 30 minutes when I tested it, and it all worked fine. Its just odd that those particular items were acting up. The fuel gauge worked perfectly. The tach board was changed several years back and hasn't acted up at all. I just hope this isn't a sign of some kind of major ground issue.
Other oddity is that now the temp gauge wont go up past the second mark ( 160 degrees I think).
It always ran higher than that (right around 180-200), even though I put in one of those new fangled aluminum radiators. I tested the gauge and got it to peg out to ground, so I assume the gauge is good. It wasn't much over 50 degrees outside yesterday, so I may not have got the car hot enough.....there's a first, a C3 owner complaining that his car is running too cold.....
Lifetime MemberIn regards to the temp gauge issue, Willcox has a video and a tech article on the subject. see this link for the tech article: http://willcoxcorvette.com/instructions/Temperature_gauge_help_page_NEW_Revised_R3.pdf
If you had the unit apart, be sure that the fiber washer is in the correct location. Good luck!
Possibilities
Double check Gauge fuse 10 amp. I would pull it and physically look at it, possibly ignition switch (since it is intermittent), ground (pillar drivers side) if tach separate might be the connector to center instrument cluster not locked into place.
ebo