'75 Tachometer Prob
Thread Starter
Racer
Joined: Jan 2003
Posts: 294
Likes: 0
From: Rochester NY
'75 Tachometer Prob
I just bought a great '75; all the gauges even work, except for the tach, which spins BACKWARDS! It worked well untilk the previous owner's last visit to the shop for brakes and some misc.
I assume this is an electronically driven tach? Could there be a plug reversed somewhere? Where would I start looking? Chilton's is no help.
Thanks!
I assume this is an electronically driven tach? Could there be a plug reversed somewhere? Where would I start looking? Chilton's is no help.
Thanks!
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Re: '75 Tachometer Prob (HDFLH67)
I don't think you can reverse wires and make it go backwards. If you wire it wrong it will just burn the circuit board. My guess is the circuit board has failed. You can get replacement circuit boards for $70 or so. Check ecklers, zip etc.
Pro
Joined: Jul 2000
Posts: 654
Likes: 0
From: Now Frozen in Michigan
Re: '75 Tachometer Prob (HDFLH67)
Welcome to the Forum!
I've never seen a tach run backwards either! Zwede has a good point about the circuit board. Check the ground circuit (blk wire from back of tach) while you're in there. Bad grounds on these cars tend to cause some wierd prob's. :crazy:
If I were testing it, I'd remove the tach, place it on a fender cover and hook up some jumper wires to double check things before purchasing new parts.
Good Luck -Rod :chevy
I've never seen a tach run backwards either! Zwede has a good point about the circuit board. Check the ground circuit (blk wire from back of tach) while you're in there. Bad grounds on these cars tend to cause some wierd prob's. :crazy:
If I were testing it, I'd remove the tach, place it on a fender cover and hook up some jumper wires to double check things before purchasing new parts.
Good Luck -Rod :chevy
