Tach Issues
Thread Starter
Racer
Joined: Oct 2021
Posts: 436
Likes: 15
From: Maryland
Tach Issues
Hello, 1982 owner here, I was fixing my ebrake cable and the locks on my door, put everything back together, turned the car on and now im having a tach issue. I didn't even touch the damn dash. Anyway, when I turn the key to accessory, the tach needle goes well below 0. When I start the car, the tach needle is about 1000 rpm less than what it should be. I haven't started diagnosing this issue, other than verifying the ebrake light works, but I wanted to ask what I should be looking at for this? How can I diagnose it? Thanks
Le Mans Master
Joined: Sep 2002
Posts: 5,236
Likes: 898
From: Myrtle Beach SC
Hello, 1982 owner here, I was fixing my ebrake cable and the locks on my door, put everything back together, turned the car on and now im having a tach issue. I didn't even touch the damn dash. Anyway, when I turn the key to accessory, the tach needle goes well below 0. When I start the car, the tach needle is about 1000 rpm less than what it should be. I haven't started diagnosing this issue, other than verifying the ebrake light works, but I wanted to ask what I should be looking at for this? How can I diagnose it? Thanks
Race Director
Joined: Nov 2006
Posts: 13,177
Likes: 7,780
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
judging by the symptoms. I would guess tach board. But I would still try bypassing the tach filter first. If I were you, I'd be reading up on how to pull the drivers side lower dash on your year car.
Le Mans Master
Joined: Jun 2019
Posts: 7,649
Likes: 2,466
From: Indiana
if the 82 is like a 79 the tach is an easy removal, and Willcox has great troubleshooting info.
That said im 99% tach board..
go to end of this long journey thread. mine also started as yours, would never zero out then got worse.
https://www.corvetteforum.com/forums...-question.html
That said im 99% tach board..
go to end of this long journey thread. mine also started as yours, would never zero out then got worse.
https://www.corvetteforum.com/forums...-question.html
Thread Starter
Racer
Joined: Oct 2021
Posts: 436
Likes: 15
From: Maryland
Yeah...its frusrating. 90% of the time its the tach but check the capacitior filter first. Given both electronic components are 40 years old, those used back then are due to wear out at some point. Copper paths get brittle break or burn out. Also search the forum here. Its a frequent topic and you can see how others have dealt with it.
Thread Starter
Racer
Joined: Oct 2021
Posts: 436
Likes: 15
From: Maryland
if the 82 is like a 79 the tach is an easy removal, and Willcox has great troubleshooting info.
That said im 99% tach board..
go to end of this long journey thread. mine also started as yours, would never zero out then got worse.
https://www.corvetteforum.com/forums...-question.html
That said im 99% tach board..
go to end of this long journey thread. mine also started as yours, would never zero out then got worse.
https://www.corvetteforum.com/forums...-question.html
Le Mans Master
Joined: Jun 2019
Posts: 7,649
Likes: 2,466
From: Indiana
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Thread Starter
Racer
Joined: Oct 2021
Posts: 436
Likes: 15
From: Maryland
Ok so seems like my car comes with the "intermittent issues" factory option, in which every damn system has an issue that fixes itself the very next day and stays dormant for a week. The tach works perfect now I did absolutely nothing to it🤡
seriously, AC/Heat, transmission, lighting, brakes, power locks mirrors and windows all work when I wanna diagnose them, but stop working at random.
seriously, AC/Heat, transmission, lighting, brakes, power locks mirrors and windows all work when I wanna diagnose them, but stop working at random.
Race Director
Joined: Nov 2006
Posts: 13,177
Likes: 7,780
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
40 year old wiring. Ain't it fun!
The joys of old car ownership!
The joys of old car ownership!
Thread Starter
Racer
Joined: Oct 2021
Posts: 436
Likes: 15
From: Maryland
my friend said when I first bought this car that it matches my personality, because of how it looks good on the outside but on the inside it’s unstable. He was right…
I’ll post here if the issue reemerges. Hopefully I’m never back
I’ll post here if the issue reemerges. Hopefully I’m never back