Tach Issue
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7th Gear
Joined: Oct 2017
Posts: 7
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Tach Issue
Hi all, newbie here that just picked up a 1975 after a lifetime of second gen Camaro's. Anyway my newly acquired pride and joy has an issue with the tach. When the car is off the tach sits at 6000 and jumps to 6500 when I crank the engine. Once it starts it goes back to 6000 and doesn't move. I have always hated anything to do with electrical and am just looking at where to start. The only thing I've done so far was bypass the filter to see if that was the issue but it still did the same thing.
Le Mans Master
Joined: Dec 2007
Posts: 6,422
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From: McHenry Illinois
Le Mans Master
Joined: Sep 2002
Posts: 5,236
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From: Myrtle Beach SC
Hi all, newbie here that just picked up a 1975 after a lifetime of second gen Camaro's. Anyway my newly acquired pride and joy has an issue with the tach. When the car is off the tach sits at 6000 and jumps to 6500 when I crank the engine. Once it starts it goes back to 6000 and doesn't move. I have always hated anything to do with electrical and am just looking at where to start. The only thing I've done so far was bypass the filter to see if that was the issue but it still did the same thing.
Given that 1975 was the first year for the HEI (high-energy ignition), those boards used thin copper pathways that, over time, burn out. As well, components get brittle. Best bet is to purchase a new board with fresh components.
Check your dash bulbs before disassembly. In the event you have lights out, you can replace bulbs while you have the dash torn apart!
Last edited by hunt4cleanair; Nov 3, 2017 at 03:57 AM.
Former Vendor
Joined: Aug 2006
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From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
This is by far the easiest way to remove the dash pad from your car. Just follow the instructions and you'll be fine.
As Tom said above... my money is on the tach board.
http://repairs.willcoxcorvette.com/w...ad-removal.pdf
So once you replace the tach board you'll need to do what is called a zero set. The video below will show you how this is done.
http://repairs.willcoxcorvette.com/1...-installation/
Willcox
As Tom said above... my money is on the tach board.
http://repairs.willcoxcorvette.com/w...ad-removal.pdf
So once you replace the tach board you'll need to do what is called a zero set. The video below will show you how this is done.
http://repairs.willcoxcorvette.com/1...-installation/
Willcox
