My tach sometimes works at higher rpms, but usually will settle to zero, or close to it, after awhile. It then sometimes jumps erratically when shifting, but still usually reverts to the bottom of the scale.

-Is there a common sending unit problem and where is it?

-Is this problem even worth trying to fix or is it something that I should accept like the other random electrical problems I have in both this truck and my Explorer?

Thanks for any input.

 

I had something like this happen in my old T-Bird (early 70's vintage). I found the problem was in the electrical connections to the distributor (which was where the tach got its signal) - they were corroded/loose/dirty (whtever). Cleaned and tightened those up and eveything was fine. If your truck has a distributor, I'd look there.

If not, I'm no help at all - sorry!

- Jack

 

Jack,

Sorry, I forgot to put in that it is the 1997 f-150 that is in the top left of my name header.

4.6 litre Triton (no distributor)

By the way, I also drive a 1965 Mustang coupe. The tach in there works fine because it was simple enough for me to install myself.

 

I'm sorry krash - I saw that you had a 97 and thought maybe that year still had a distributor.

It still sounds like a poor electrical connection to me though. Perhaps something that loses conductivity when it gets warm? Unfortunately, I have no knowledge of the innards of your truck. :o

- Jack

 

im having the same problem with my 97 but not as bad normal works but goes dead for a few secs then come back not sure if its a bad connection or a sensor some where im about ready to tear the backwards from the cluster till i find the problem but if i find any thing you'll be the first to know