79 L82 tach problems still
Thread Starter
Intermediate
Joined: Apr 2006
Posts: 26
Likes: 0
From: VANDERBILT PA
79 L82 tach problems still
I've done everything to the tach, REPLACED FILTER ,CHECK THE WIRING, REPLACED THE SPEDO BOARD....all that is left is to change the tach board???? at a cost of about 65.00 that's not an issue however the needle will not fall all the way down to zero? So should I just pay the extra bucks to have the whole tach rebuilt....so to speak or just role the dice and try the board?
Last edited by nekkutter; May 3, 2007 at 07:49 AM.
Pro
Joined: Jan 2007
Posts: 657
Likes: 0
From: Wisconsin
if you mean when you shut the car off, I have bad news for you; you wasted your time. The tach needle will stop where it wants, not at zero, when you turn the key off. Then when you turn key back on it'll drop to zero before going back up.
Dont feel bad, I thought the same thing until I read it in one of the Vette magazines recently; they had an article about it.
Dont feel bad, I thought the same thing until I read it in one of the Vette magazines recently; they had an article about it.
Last edited by 79L82owner; May 3, 2007 at 12:58 AM. Reason: added dont feel bad etc.
Le Mans Master
Joined: Jan 2007
Posts: 7,990
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From: Omaha NE
2025 c3 ('74-'82) of the Year Finalist - Unmodified
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I bought mine new and thought the tach had a problem my first night out since it didn't go back to zero.....
Found out from the dealer the next morning that they all did it....
Found out from the dealer the next morning that they all did it....
Team Owner
Joined: Jun 2000
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From: Southbound
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Pro
Joined: Dec 2002
Posts: 560
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From: Mooresville NC
Sounds like you replaced most of the main components except for the circuit board. On thing though, make sure the filter has a good ground off the manifold. Check with a continuity tester or light.
All said and done, I would price out having the tach rebuilt. If total price is reasonable vs the $65 tach board, I would go that route. At least you would get a tach that was tested and repaired along with the circuit board. Most of the rebuilders replace the circuit board as a standard in their rebuild with something they have as reliable.
Good luck.
All said and done, I would price out having the tach rebuilt. If total price is reasonable vs the $65 tach board, I would go that route. At least you would get a tach that was tested and repaired along with the circuit board. Most of the rebuilders replace the circuit board as a standard in their rebuild with something they have as reliable.
Good luck.
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Drifting
Joined: Nov 2005
Posts: 1,795
Likes: 1
Sounds like you replaced most of the main components except for the circuit board. On thing though, make sure the filter has a good ground off the manifold. Check with a continuity tester or light.
All said and done, I would price out having the tach rebuilt. If total price is reasonable vs the $65 tach board, I would go that route. At least you would get a tach that was tested and repaired along with the circuit board. Most of the rebuilders replace the circuit board as a standard in their rebuild with something they have as reliable.
Good luck.
All said and done, I would price out having the tach rebuilt. If total price is reasonable vs the $65 tach board, I would go that route. At least you would get a tach that was tested and repaired along with the circuit board. Most of the rebuilders replace the circuit board as a standard in their rebuild with something they have as reliable.
Good luck.
you might want to try PM-ing him about yours
Drifting
Joined: Nov 2003
Posts: 1,634
Likes: 4
From: Northern NJ
St. Jude Donor '04 & '05
Glad to hear it's still working OK. I suspected it would be fine. Probably will last as long as it did the first time before it needs attention again.
Hope to be able to get together this year sometime.
Racer
Joined: Jul 2005
Posts: 499
Likes: 1
From: Winnipeg Manitoba
It's electronic, not mechanicial. When the electronic signal stops (ignition turned off), the needle has no juice to go anywhere, so it parks. Your digital alarm clock works the same way. When the electricity goes out, the clock stops with the time it had when the signal was interrupted.
Its loss of power that freezes the tach, not the loss of signal.
When the ignition is turned off, you lose power. The tach parks.
When you turn the ignition back to run, power returns to the tach.
The tach swings back to zero because you don't have a signal (engine off).
