Got a used, but nice sun super tachtwo (II) Just want to make sure I have the wiring figured out right Its has 4 wires, a black, a red,a blue ,and green ..blue lights, Red 12 volt, and black ground, green to coil, does this sound correct. Thanks

Sounds right. Green should be on the neg. coil terminal

The supertac II is a plastic POS , check it accuracy BEFORE you waste time doing a full install , the one I THREW OUT was 400 low at idle and 1500 rpm LOW at 5000 .

but yes GREEN is the tach signal

Mine is off by about 500 rpm at 6K. I am bouncing off of my 6K rev limiter at 5500. I changed limiter modules and it is around 5-700 rpm off. It also shows that my idle is at 900 and the tach in the timing light shows 1100 rpm. I would return it to Napa but they special ordered it in and cant warranty it. On a street car you should have no problem.

Don't be discouraged. The Autometer I race with is off about 500 at high end. With the MSD stuff, it's really just there to look at, I guess. For fun, in a nostalgic car, I'd go ahead and use it. Heck, I think I even have an old chrome one on a shelf somewhere! lol

POS. not worth the powder to blow it up.

I have one in my car and it only lasted a year or so before it quit.

Thanks guys for all the good infor. I only wasted $10.00 on is, so if it fries or is off, somewhat, Ill say some money and pic up something alot better.