can't get my tach to work!!!! runnin the 04 gto motor, pin 25 of c206 is tach signal, well i hooked it up to my stewart warner tach, set to 4cyl mode. i don't get no movement at all from the guage. i set it to 8cyl mode, same crap...anyone got ideas? i tried some searches but came up empty handed.

Haha yup... Same here brand new Autometer pro comp and same b/s had me foiled for a while... Tried everything too. Called Autometer tech support and verified my wiring was okay and would have sent it back too if it wasn't such a pain to do so from Canada. After endless searches I found an answer.

Solution was to boost the signal from the PCM to the tach. It seems the output is not strong enough to power many aftermarket tachs so I put a 10K resistor to 12V+ ign and spilced that into the tach signal feed from the PCM to the tach and bingo shes alive.

I bought a pack of five resistors from Circuit city for five bucks.

i'll give it a shot,...hmm RIGHT NOW!!! lol...

Perfect!! thanks man.
oh by the way....Radio shack, 5 pack of 10k ohm resistors, $1.08

Dang I got ripped off.....

Glad it worked out for ya