What would cause this?
Race Director
Joined: Feb 1999
Posts: 19,659
Likes: 34
From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
Re: What would cause this? (Skyhigh)
My 79 did this. I never knew the reason why it did this. Anyone know?
Melting Slicks
Joined: Jul 2002
Posts: 3,000
Likes: 22
From: Boulder Creek California
Re: What would cause this? (Quinn_Seipp)
I don't know the exact reason, but the tach is electrical, when you turn the ignition off it just stops wherever it was at. If I knew how the tach worked internally, it would probably be more clear why. I've stuck it at 3000 just for fun. hehe
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
Re: What would cause this? (paul67)
I know its completely normal for GM cars of that era but I do not know the reason it was designed that way.
-Steve
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Verdad Gallardo
Safety Car
Joined: Jun 2002
Posts: 4,759
Likes: 2,508
From: Buckeye, AZ
St. Jude Donor '12-'13
Re: What would cause this? (Skyhigh)
It's normal for '78s. I know stock cars use a "tell tale" tach which allows them to see what the rpm was at if an engine failure occurs. But it seems to me that isn't he case on Vettes, because if the engine died the tach would drop and freeze until you turn off the ignition. I wouldn't worry about this......I have cehcked many tachs on that vintage and they all work that way....in other words it's not defective.
Instructor
Joined: Aug 2003
Posts: 104
Likes: 0
From: Newfane NY
Re: What would cause this? (Skyhigh)
As we all know by now, this is an electrical, not a cable driven guage and when the key is off, no signal to make any change in its location, so it will just stay there untill it gets "juice" again. :) Hope this helps. (its a design thing) :crazy:
