Stereo & Electronics - Proform shift light hookup question

I saw one in jegs last night for $45. My question is where does the signal come from? Obviously, one wire goes to a ground, but where does the rpm signal come from on my 99 Z28? I got pretty good power now & want to make sure I'm shifting on time, Fred :judge:

PCM. Check out raptorperformance.com. It has instructions that tell you how to wire em up. If you need help I can write you out a very detailed explaination, but that page might suffice for ya.

I hooked the shift light up. I hooked the ground to a good spot. I hooked the power wire to the pink wire on the ASR switch & connected the signal wire to pin 10(White wire) & the light don't seem to work right.

I haven't drove the car anywhere but when i set the light to come on at 3,000 rpm's & then rev it up in the driveway the light doesn't come on. I did notice at idle the light blipped on a few times. :mad:

For what it's worth the tach in the dash still works perfectly. What the hell is going on, Fred

ive read that proforms are iffy on our cars good luck.

Our cars send out a very low voltage to the tachometer as opposed to most cars. It is possible that your tach's threshold is not low enough to pickup the tach signal. Also...any reason you connected the power wire to your asr?