Tachometer Not Working (1990 Automatic)
Thread Starter
Team Owner
Joined: Nov 2001
Posts: 34,124
Likes: 105
From: Pensacola FL
Tachometer Not Working (1990 Automatic)
Since you guys/gals have been so helpful, I've got another question. My tach swings all the way up when the car is started, but then doesn't read the rpms at all. Can anyone point me in the right direction on tracing out the wiring? Thanks in advance and I appreciate the nice reception for a newbie. Ben
Thread Starter
Team Owner
Joined: Nov 2001
Posts: 34,124
Likes: 105
From: Pensacola FL
I checked the wires at the distributor...red to "BAT", white to "TACH" and they are both plugged in. If it helps any, the tach needle seems to really slam down when the engine starts. Polarity issue somewhere? Thanks for the help! Ben
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
1990 tachos are well known for a multitude of unexplained problems , mostly inaccurate readings or not working.
My 90 has unsolved problems similar to yours.Could check the tach filter but it changed nothing on mine
My 90 has unsolved problems similar to yours.Could check the tach filter but it changed nothing on mine
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Gordon Killebrew says most of our C4 tach problems are cause by water in the bulkhead connection. The tach pin is on the lower row. Seems like the General didn't seal the top and sides of the connection, and he also says to check the cowling drip tube-make sure it's not dumping directly on the Bulkhead connection-his recommendation, disconnect it and blow it out, leave the black looking gunk in there, it's an anti corrosive grease.Then seal the top and sides. One other thing you might check, make sure the tach filter is still grounded to the bell housing..good luck there, it's a bi@*ch to see.
