Help with my Tach

[krscholz]

Tach not working. Any ideas what I should do? Automatic Transmission. Thanks

 

[Nobody Cares]

Electronic tach, correct ?

 

[bill81vette]

if it is electronic it may need a new board....

 

[krscholz]

Thanks, the car is an automatic - wouldn't that be electronic. 4-Speed is mechanical Correct?

 

[LVMYVT76]

wrong, all with HEI were electronic. You probably have a bad board or check the tach filter to make sure ther is signal going thru it. Does move at all?

 

[krscholz]

No, its stuck. Its probably the board. How do I locate the filter?

 

[duke94]

Here's a How to article from ZIP. Go to the last page and there are a couple trouble shooting tips. You may have lost the ground or 12V.

http://www.corvettemagazine.com/2005/june/tach/tach-lead.asp

 

[minifridge1138]

When my board went bad my needle still moved. When the key was turned to "ON" the needle would jump to 1000 and slowly climb until it maxed out.

It even did this when I disconnected the wire going from the tach to the distributor.

The tachometer looks like this:
http://www.ecklers.com/product.asp?pf_id=46137&dept_id=1135
It should be inline with the wire that runs from your distributor to the firewall.

Be VERY CAREFUL buying a tachometer board.
A lot of corvette sites sell boards that are not calibrated and do not accept returns on opened/installed electronics. I know because I got screwed (won't name names).
Make sure you buy one that is calibrated.

 

[LVMYVT76]

The filter looks like a capicator on an old distributor system, mounted on the intake manifold between the dist and the firwwall, the feed from the dist goes to the filter and then to the tach. If the wire is broken or the filter has gone open, no feed to the tach. I think you can bypass the filter to see if the tach is working, then check out the filter to see if it is defective. They are sold by different vendors of corvette parts.

 

[6880 Mike]

Make sure it's plugged in well at the distributor.