ironspider

ALright. I've read all the past articles on the alternator vs regulator issue. cant tell what ive got wrong. Everything seems to operate normally. 13.7 volts or so at 1500rpm, 12v when not started. Then loaded it still looks like a minor drop to 13.4 or so. My battery discharged while sitting for a mere week. Everything has been fine for a couple of weeks.

However, the tach goes bananas ONLY when i turn on the lights. Then its sporadic and does stuff like max out when the clutch is pressed. Sigh. Heeeeeeeeelp.

emac

Hi
Dont know the year you have and Im sure others on this site will have much more knowledge than myself, but I might have the answer. I have a 81sc
and had problems similar to yours. My tach would just go crazy at any given time. I did the normal checking, pulled the unit and checked for loose wires etc.etc. It ended up being a bad tach. I looked for new ones and the prices were a little high -- so I went to e-bay and was able to purchase the entire cluster from a wreck for 169.00. The only thing I had to do was replace the plastic lenses with my glass. Everyting is fine now.

Ernie

addictionms

clean all the grounds on the instrument cluster first and try it, older cars have lost of problems due to the common ground on the instrument cluster.

Jim