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Well, I fought that Speedo and Tach back into place…and I will tell you that the next time, I WILL REMOVE THE COLUMN. Anyway here’s the issue, I secured all the wires and grounds, I double and triple checked everything, when I went to switch on the battery from my disconnect, the tach went to Nearly zero, just one hash mark away from zero, I started the car and it works perfectly, shut the car off, tach went to neatly zero, then I switched off the battery disconnect, and it goes to 10, then I switch on the battery and it goes to nearly zero again, then switch off the car, it stays at 15, then I restart the car and it goes to nearly zero again ? If I wiggle the dash with the power disconnect off, it will climb even higher???? Any help on this would be super appreciated!!!
The tach won't read Zero when the power is OFF. It just ends up where it ends up. If it works correctly when power is applied, that's how it is supposed to work by its design.
Thanks, I did realize that during a test, but this thing was staying at 15 and 10, even with if the. power was on, and sometimes at 1k, on or off…I took apart and recalibrated it, now it appears to work great!
I took it apart, and pulled the small circuit board and checked it for any damage, then I hooked it up to a battery and checked the needle position..then I would move the needle to the correct position, after several attempts I finally got it back to Zero. Then after I did that, I put it back together and tested it once more…PERFECT. I think sometimes something can interfere with the original setting since I’ve had it out for months. ie “static” Who knows what caused the issue to begin with. But I’ll put it face in the car tomorrow and see if it works correctly.
There is a little electronic 'filter' gizmo located on the engine (by the distributor) which blocks extraneous 'junk' pulses from getting into the tach circuit. That may be the REAL problem. Your tach calibration may now be masking that issue. But, if it works and you're happy, so be it. If the tach starts increasing its reading at ZERO again, you may want to deal with the filter issue.
Tach mystery
