You all were so helpful on my last electrical issue and got it resolved I'm down to the last problem when I turn on the ignition switch the tach goes to max and doesn't return or move till the switch is turned off. It and the distributor are wired to the - side of the coil and even if i unplug the grey wire it stays maxed out. When I unplug the blue wire from the fuse box it goes down also. Thanks in advance for any help.
69 Barracuda tach
- Thread starter drgordi
- Start date
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Grey wire to -ve should be correct. What kind of coil? Has tach got new electronic board in it?
Blue wire possibly wired wrong.
Blue wire possibly wired wrong.
Heres pics of factory wiring. Dark blue from fuse panel to back of tach amd grey from back of tach to coil -ve.
Go to mymopar.com and download as much as you can.
Go to mymopar.com and download as much as you can.
Who's boards? I think you have to switch the connections on the back but dont quote me. Hate to fry it.
So new boards on entire cluster or new internal board for tach?
Pic of my 69 with electronic board.
Pic of my 69 with electronic board.
Yours looks like mine! I believe it is correct!
I think Steve's got reversed when the board was replaced.
Point's should not require an upgrade like we have done! Likely a bad tach.
I think Steve's got reversed when the board was replaced.
Point's should not require an upgrade like we have done! Likely a bad tach.
You might unplug the gray under the hood and see what it does. There should be a connector just past the engine on the firewall before it enters the lone bulkhead entry point. It does not go through the main bulkhead.
I replaced the board in mine this winter and it worked just great today while cruising down to a car show!
The board inside the tach itself?
Yes!
They are available from multiple sources, I used the one RTE offers with calibration jumpers and was a simple deal. I changed to Pertronix III and the tach would not function correctly. It works great now!
They are available from multiple sources, I used the one RTE offers with calibration jumpers and was a simple deal. I changed to Pertronix III and the tach would not function correctly. It works great now!
If you go that route just be carefull as the fiber washers are pretty dang old and can be crumbly. Just take it slow and easy and keep track of the washers and how they came out. Patience is they key here if you want to save the original!
If/when you replace the board, ask the supplier for new fibre washers.
Stock coil? I heard MSD coils can cause issues.
Stock coil? I heard MSD coils can cause issues.
Had it completely apart and nothing looked out of place. Put it back together and same results. Still pegs out when power is applied from key and stays there while the motor is running until the key is turned off. Another 3 inches of wiring would help with installation and less sharp objects under the dash. Good thing is all other factory gauges are working perfectly.
Did you open up the tach?
The blue is +12v ACC power. The gray Is -coil. Mine had on the inside red+ and white points. It never pegged like you are saying but did not sweep correctly with the electronic ignition. It would seem fine at idle put did not respond well with throttle. The Tach may be toast and changing the board may not help it!
Seems like a crap shoot for $100 bucks. Points should work just fine with the original regardless of the coil used.
The blue is +12v ACC power. The gray Is -coil. Mine had on the inside red+ and white points. It never pegged like you are saying but did not sweep correctly with the electronic ignition. It would seem fine at idle put did not respond well with throttle. The Tach may be toast and changing the board may not help it!
Seems like a crap shoot for $100 bucks. Points should work just fine with the original regardless of the coil used.
No,
All my stuff functioned and just needed modernizing. I replaced my other gauges with units sold by Chargerspecialties and are happy with the outcome. They or others can likely help you.
If you bench test the tach and apply +12 to the blue terminal with a ground jumper to the case does it peg? Are you sure someone has not not already opened it and may have reversed the connections! They are mounted on a small rectangular fiber board that is easy to reverse like Steves is. Like I said mine was blue plug and red inside. Grey spade and white inside.
Sounds like you have done the work try CS or maybe Instrument specialties or replace with one aftermarket units and or source another original.
Good luck and happy Moparing!
Good luck and happy Moparing!
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