TA22 Tacho\Wires problems

[1974_TA22]

When i start my car up my tacho seems to be working... shows idle rpm... however when i rev even a little bit it just stops and drops to 0
I have the feeling its a bad earth.
But Where/how does the tacho wire into system? where do i find it?
Or could it be the taco itself?
im running a 2TG btw...if that helps at all

[TRAV-KE55]

Being a 2TG wont make any diffirence to the tach, sounds like the tacho is buggered, maybe a bad earth aswell. If its a stuffed tach let me know i have one that you can have for nothing
Trav

[TA22 GT]

The tacho gets its signal from the coil. The negative side from memory. Check the connections on the coil is good.
Sounds like a bad earth to me. Does the tacho light work alright? If so it will prove that at least 2 of the 6 wires on the rear of the tacho are connected properly.

Does you front windscreen leak? If it does it could have created a bad connection under your dash. You could also try and move the connection at the rear of the tacho around a bit to try and get a better connection. You should be able to reach it without removing the instrument panel. Just get your hand behind the tacho, not much room but worth a try.

Hope this helps,
Simon
http://users.chariot.net.au/~stmezz/celica.htm