Connection issue after electronic Tach conversion
Thread Starter
Drifting
Joined: Dec 2004
Posts: 1,714
Likes: 42
From: Austin Texas
Connection issue after electronic Tach conversion
This is an electrical question for ya.
I had the tach for my 74 converted to electronic by Roger at Corvette Clocks. I am about to lose my mind installing it though.
The issue is the tach works fine UNTIL I connect any of the 5 little lights with the metal clips to the back of it. There is no issue if i connect the light with the rubber grommet.
Once I connect one of those lights, the tach moves backwards to 5500 or so and stays there, engine on or off.
I guess it is a ground issue but dont know how to resolve it.
Do I need to ground the speedo and tach cluster? I see they have a metal strip between them.
please help if you can ,
John
I had the tach for my 74 converted to electronic by Roger at Corvette Clocks. I am about to lose my mind installing it though.
The issue is the tach works fine UNTIL I connect any of the 5 little lights with the metal clips to the back of it. There is no issue if i connect the light with the rubber grommet.
Once I connect one of those lights, the tach moves backwards to 5500 or so and stays there, engine on or off.
I guess it is a ground issue but dont know how to resolve it.
Do I need to ground the speedo and tach cluster? I see they have a metal strip between them.
please help if you can ,
John
Thread Starter
Drifting
Joined: Dec 2004
Posts: 1,714
Likes: 42
From: Austin Texas
Thank you! Now I am trying real hard not to blow anything up and could use some guidance on how or where to attach the ground to the clusters.
Do I run a ground wire to the metal pan where the lights connect into? how is it grounded from the factory? and is it ok just to run a new ground wire there.
Do I run a ground wire to the metal pan where the lights connect into? how is it grounded from the factory? and is it ok just to run a new ground wire there.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I think you need to call Roger. If the dash lights are not turned on they are supplying the tach case with a ground if its not already grounded by one of the 14 black wires.
From what your describing it sounds as if you might have installed something wrong. Just a guess but I'm thinking when you run a separate ground its going to do the same,could be wrong,I'd call Roger.
From what your describing it sounds as if you might have installed something wrong. Just a guess but I'm thinking when you run a separate ground its going to do the same,could be wrong,I'd call Roger.
Thread Starter
Drifting
Joined: Dec 2004
Posts: 1,714
Likes: 42
From: Austin Texas
This really helps, thank you. After 3 years I have clearly forgotten how this was put together.
I found the ground spades and connected the ground connectors and still have the issue. I think it is safe to say that I have a ground problem. However it confuses me why the tach works when out of the cluster and not in the cluster.
Thanks again Roger.
I found the ground spades and connected the ground connectors and still have the issue. I think it is safe to say that I have a ground problem. However it confuses me why the tach works when out of the cluster and not in the cluster.
Thanks again Roger.
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Thread Starter
Drifting
Joined: Dec 2004
Posts: 1,714
Likes: 42
From: Austin Texas
Just as I was about to give up I noticed one of the rubber washers was broken on one of the screws. I removed the screw and it seems to have fixed it.
I will call Corvette Clocks monday and order a replacement rubber washer.
Thanks!
I will call Corvette Clocks monday and order a replacement rubber washer.
Thanks!
Last edited by johnt365; Jun 26, 2010 at 09:53 PM.
