Tachometer dead
Thread Starter
Instructor
Joined: Jan 2014
Posts: 102
Likes: 0
From: Hudson valley Ny
Tachometer dead
Hello everyone
My tach doesn't work on my 76
So I replaced the tach filter first hoping that may be it
That doesn't seem to be the problem
I have heard the next thing to try would be the circuit board behind the tach ?
That probably won't be fun does any one have any ideas on this thanks so much John
My tach doesn't work on my 76
So I replaced the tach filter first hoping that may be it
That doesn't seem to be the problem
I have heard the next thing to try would be the circuit board behind the tach ?
That probably won't be fun does any one have any ideas on this thanks so much John
Safety Car
Joined: Aug 2001
Posts: 4,883
Likes: 11
From: North Easton Mass
Hello everyone
My tach doesn't work on my 76
So I replaced the tach filter first hoping that may be it
That doesn't seem to be the problem
I have heard the next thing to try would be the circuit board behind the tach ?
That probably won't be fun does any one have any ideas on this thanks so much John
My tach doesn't work on my 76
So I replaced the tach filter first hoping that may be it
That doesn't seem to be the problem
I have heard the next thing to try would be the circuit board behind the tach ?
That probably won't be fun does any one have any ideas on this thanks so much John
Willcox sells a nice replacement board that has less components than the other vendors' boards, and has an adjustment pot. I found the best deal on their board was through their ebay store because they offered free shipping but if they have a sale going on through the forum that might change. I think there are some videos on the Willcox site for installation also.
Rick B.
Le Mans Master
Joined: Sep 2002
Posts: 5,236
Likes: 898
From: Myrtle Beach SC
The board is the most likely culprit. Components fail after 30+ years and may fry etches on the board. You have to remove the tach to check the board anyway so you will be half way through the repair at that point.
tach boards & what goes wrong
wilcox 1975-77 tach board replacement
Last edited by hunt4cleanair; Mar 19, 2014 at 05:29 AM. Reason: add Wilcox link
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
There is a ton of tach info on my sight and if you do a search here you'll find tons more.
For you.. and I doubt anything will change... but by-pass the filter and see if the tach works.
Test continuity from the tach connector to the tach inside the car. From A to B.
Verify you have power and ground to the tach by checking the terminals.
If you have power, ground and continuity then you're probably going to need a tach board.
If you decide to remove the tach take a hard look at removing the lh dash pad made easy... it will walk you through the process.
http://willcoxcorvette.com/repairand...lp.php?hID=318
Corvette Left Hand Dash Pad Removal Made Easy 1968-1977
Willcox
http://willcoxcorvette.com/repairand...lp.php?hID=290
Corvette Tachometer Testing, Removal, Board Installation, Video Link 1975-1982
http://willcoxcorvette.com/repairand...lp.php?hID=314
Corvette Tach Filter Installation Instruction Sheet Revised 3-11
1975-1977
For you.. and I doubt anything will change... but by-pass the filter and see if the tach works.
Test continuity from the tach connector to the tach inside the car. From A to B.
Verify you have power and ground to the tach by checking the terminals.
If you have power, ground and continuity then you're probably going to need a tach board.
If you decide to remove the tach take a hard look at removing the lh dash pad made easy... it will walk you through the process.
http://willcoxcorvette.com/repairand...lp.php?hID=318
Corvette Left Hand Dash Pad Removal Made Easy 1968-1977
Willcox
http://willcoxcorvette.com/repairand...lp.php?hID=290
Corvette Tachometer Testing, Removal, Board Installation, Video Link 1975-1982
http://willcoxcorvette.com/repairand...lp.php?hID=314
Corvette Tach Filter Installation Instruction Sheet Revised 3-11
1975-1977
Thread Starter
Instructor
Joined: Jan 2014
Posts: 102
Likes: 0
From: Hudson valley Ny
There is a ton of tach info on my sight and if you do a search here you'll find tons more.
For you.. and I doubt anything will change... but by-pass the filter and see if the tach works.
Test continuity from the tach connector to the tach inside the car. From A to B.
Verify you have power and ground to the tach by checking the terminals.
If you have power, ground and continuity then you're probably going to need a tach board.
If you decide to remove the tach take a hard look at removing the lh dash pad made easy... it will walk you through the process.
http://willcoxcorvette.com/repairand...lp.php?hID=318
Corvette Left Hand Dash Pad Removal Made Easy 1968-1977
Willcox
http://willcoxcorvette.com/repairand...lp.php?hID=290
Corvette Tachometer Testing, Removal, Board Installation, Video Link 1975-1982
http://willcoxcorvette.com/repairand...lp.php?hID=314
Corvette Tach Filter Installation Instruction Sheet Revised 3-11
<a href="http://www.youtube.com/watch?v=bA3khKLw2Ys">YouTube Link</a>
1975-1977
For you.. and I doubt anything will change... but by-pass the filter and see if the tach works.
Test continuity from the tach connector to the tach inside the car. From A to B.
Verify you have power and ground to the tach by checking the terminals.
If you have power, ground and continuity then you're probably going to need a tach board.
If you decide to remove the tach take a hard look at removing the lh dash pad made easy... it will walk you through the process.
http://willcoxcorvette.com/repairand...lp.php?hID=318
Corvette Left Hand Dash Pad Removal Made Easy 1968-1977
Willcox
http://willcoxcorvette.com/repairand...lp.php?hID=290
Corvette Tachometer Testing, Removal, Board Installation, Video Link 1975-1982
http://willcoxcorvette.com/repairand...lp.php?hID=314
Corvette Tach Filter Installation Instruction Sheet Revised 3-11
<a href="http://www.youtube.com/watch?v=bA3khKLw2Ys">YouTube Link</a>
1975-1977
To do the other tests I assume you have to have dash apart ? Thanks
Thread Starter
Instructor
Joined: Jan 2014
Posts: 102
Likes: 0
From: Hudson valley Ny
Could I of hooked up filter backwards because the wiring in the diagram shows it the other way one of the wires had two colors and the instructions said to put that one to the distributor
Should I try and reverse them thanks
Should I try and reverse them thanks
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Thread Starter
Instructor
Joined: Jan 2014
Posts: 102
Likes: 0
From: Hudson valley Ny
Looks like its probably the tach circuit board
Man that project looks involved from the willcox info i read
I got a quote from my local vette shop of 800 bucks for labor
I don't know what I am gonna do
Man that project looks involved from the willcox info i read
I got a quote from my local vette shop of 800 bucks for labor
I don't know what I am gonna do
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
The instruction sheet for removing the left dash pad should help you get the pad out... it's really not that bad of a job. It takes us about 3 hours to take it out and put it back in. 800 seems strong for just labor, but in all fairness to your local shop, we do this job all the time, and they probably don't.
Thread Starter
Instructor
Joined: Jan 2014
Posts: 102
Likes: 0
From: Hudson valley Ny
The instruction sheet for removing the left dash pad should help you get the pad out... it's really not that bad of a job. It takes us about 3 hours to take it out and put it back in. 800 seems strong for just labor, but in all fairness to your local shop, we do this job all the time, and they probably don't.
Former Vendor
Joined: Aug 2006
Posts: 76,656
Likes: 1,853
From: Jeffersonville Indiana 812-288-7103
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
The tach picks up power from the pink wire, go to the back of the tach and see if you have power with the key on. This pink wire is also the power feed for the other small gauges... and comes from the gauges fuse in the dash.
Willcox
Willcox
Thread Starter
Instructor
Joined: Jan 2014
Posts: 102
Likes: 0
From: Hudson valley Ny
But am confused on how I will check power when the steering column is out
Racer
Joined: Oct 2013
Posts: 317
Likes: 98
From: VT
tacho
mine's at 2000. just wondering if it's possible to diagnose the problem (bad tach, bad board, no power) from the symptoms / what the tach is showing. but folks usually post "tach is bad" w/out details.
Melting Slicks
Joined: Mar 2007
Posts: 2,520
Likes: 11
From: Hinckley OH
Just one more thing to check before you tear into the dashboard. Make sure you have a tach signal from the distributor. The tach on my '76 doesn't work but neither does my hand held diagnostic tach if I hook it up. The hand held tach works on my '74 and my Jeep so I think the problem is in my coil connection inside the distributor cap. I just haven't bothered to take it apart yet.
Thread Starter
Instructor
Joined: Jan 2014
Posts: 102
Likes: 0
From: Hudson valley Ny
Just one more thing to check before you tear into the dashboard. Make sure you have a tach signal from the distributor. The tach on my '76 doesn't work but neither does my hand held diagnostic tach if I hook it up. The hand held tach works on my '74 and my Jeep so I think the problem is in my coil connection inside the distributor cap. I just haven't bothered to take it apart yet.
Thread Starter
Instructor
Joined: Jan 2014
Posts: 102
Likes: 0
From: Hudson valley Ny
Just one more thing to check before you tear into the dashboard. Make sure you have a tach signal from the distributor. The tach on my '76 doesn't work but neither does my hand held diagnostic tach if I hook it up. The hand held tach works on my '74 and my Jeep so I think the problem is in my coil connection inside the distributor cap. I just haven't bothered to take it apart yet.