wrea398

Hello. Im new to this forum and was hoping to get some assistance. I have a 1966 Corvettewith a new LS3 engine. I had the tach conversion done by "Corvette Clocks by Roger". He says to use MSD 8918 pickup adapter to make it work. All wires hooked up correctly and I have no tach. I hit the key and get the needle to bump slightly, basically only tellin g me I have voltage to the tach. The needle is way below ZERO at the 6 o'clock position when no power is applied. It should go to ZERO when you kit the key. This one doesn't. The 12V source and grounds are dedicated soley to this tach and MSD unit. I have 12.09 volts at tach when key is switched ON. Needle NEVER leaves the 6 oclock position. You only see it bump about an 1/8" when the 12v is applied.

Thought it could be the MSD unit and a bad signal path. I removed the MSD and wired directly to the ECM white wire. Still nothing. I unhooked the tach and wired in an aftermarket tach set to 4cyl setting. It worked when I used the ECM wire and a pull up resistor between 12V and SIG wires. It worked better on 2cyl setting but I have a 10K resistor inline which may be too much. Rewired in the Roger tach to ECM and same resistor, NOTHING. All in all, the tach wont do anything except bump a little when I hit the key.

BAD TACH??

Smo's04Gto

iTrader: (8)

Do a search I think your resistor is to large.