75 tachometer

[humphbri]

Hi all

The tachometer in my car is not working (like many others I think). I have a new circuit board but before I go to trouble of changing it I thought I would see if anyone has had similar trouble. The web site where I bought the circuit board says that replacing the circuit board fixes 95 pe% of tacho problems and went on to describe how these tachos jump all over the place. Mine doesn't move at all, which makes me think it might be a probelm with the connection to the distributer cap. Has anyone corrected a tacho that doesn't move by changing the circuit board?

Cheers

 

[6880 Mike]

Check the electrical connection at the distributor. Sounds like you've got a bad connection.

 

[L48]

If I recall correctly, my dead tach would sit around 1000 when the engine was off, then go to zero when you started the car. There was no jumping around when it was running. New circuit board fixed it, but it was a job taking apart the dash to get it.

It might be worth a continuity test on the tach wire before you completely disassemble the dash to get the tach out.

I was also thinking about connecting a meter or aftermarket tach temporarily, but I'm not sure that would prove anything.

 

[humphbri]

Thanks guys

I will check the connections before I go pulling the dash to pieces.

Cheers

 

[White75]

Check the electrical connection at the distributor. Sounds like you've got a bad connection.

Is there a faq on checking this

 

[humphbri]

Is there a faq on checking this

Thanks for the suggestions.
As it turns out, it was the tachometer filter. Power going in one end of the filter and not coming out the other. No need to relace the circuit board, Cheers