Autometer Monster Tach
My wife bought a New Old Stock Ford Motorsports monster tach with external shift lite for her 92. It was still in the box and plastic wrap. I put it in the car over the weekend. It came with a duraspark type plug made on the wires. I cut that off and hooked it up Red-switched 12v, Black-Ground, Green-tach(-), white- dash lights. It works, except it is reading 700 rpm too high across the rpm range. I took another monster tach I have apart and looked inside. There are 3 pots on the circuit board.
I searched and searched all over the internet and did not find anything about tweaking those pots. Short of sending it to autometer and getting it recalibrated, does anybody know if one of those pots is the zero adjustment?
I figured maybe the duraspark system still used the ballast resistor and had closer to 8 volts on the coil than the 1992 with 14 volts on the coil. I read 12.8 on the minus side of the coil with it running. I was going to call autometer today, but had lots of breakdowns out in the field and didn't get to the office.
I know everyone will probably say just get rid of it and get a tach that is right for the car. But momma likes it. It is cool looking with the white face gauge and says ford racing and SVO on the face. In fact, she likes it even tho it is inaccurate, since it is cool looking. I have a spare regular monster tach with black face that works and she won't let me put it in the car.
thanks, and I apologize for the long post
2013 GT Roush Stage1 TVS