Recently my tach started working intermittently cutting in and out. Before I start digging under the dash I thought I’d consult with the brain trust to see if you guys have any ideas. Thanks in advance!
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Stock setup?
Check your grounds. If the rear plate to the ZF trans was painted be sure the ground strap is grounded to metal and not paint.
MSD ignition with tach adapter. Other than that, stock.
I had this exact issue . I had it serviced and was told that the Jewel movement needed lubrication.
I also had it re calibrated at that time and was told that it was off several hundred rpms.
Even though the tach case is sealed air tight, after 50 years there was enough magnetic dust accumulation on the movement to effect the needles action.
PM me here if you need a recommendation for the repair.
Thanks all.
and thanks Doug, I’ll let you know when and if I need it.
I had a ground wire loose on the back of my tach which created intermittent and inaccurate readings. Could be something simple as that.
I’ve never removed the tach from the dash.
mine is a 73 L single pod dashboard.
I would rather ask a stupid question than make a stupid mistake. How do you remove the tach from the dashboard without damaging anything?
Removing the tach isn't much fun. I would recommend laying in the floor and trying to check the wires before you remove it.
The ground wire came loose on mine and is highlighted in red in the picture.
If you have to remove it there is a U-shaped bracket that has two nuts on it to hold the tach in place against the back of the dash.
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Thanks so much for the info and the pictures. That’s a big help!
I find that you need to drop the steering column down so that you can reach one of the mounts. That's the only way to get at it.
It also help if you can (easily) pull your driver’s seat, to give yourself more room to lay on the floor…. Seriously!
Rocky