Hey all, i'm new here and have been searching for some answers but haven't been able to find any. I bought an '88 GTA a while back and the last owner had installed a "Monster" racing tach w/shift light right under the dash in front of the headlight switch and interior dimmer switch (kind of annoying as i hit my leg off it every time i get in and out). What i'd like to know is which wires should i be looking for to rewire up the old digital tachometer? I can see it's getting power to it (lights up when ignition is turned on) but it there is no signal being sent. Any help is greatly appreciated! Thanks!

 

Could be that he installed the aftermarket because the original didn't work. Let me see if i can find my '88 service manual which has the whole shebang (schematics and problem solving techniques). Earliest i could even scan this if i find the book would be wednesday, so if someone has the book and schematics and can scan them before then, feel free to help this guy out! Good luck!

Jon

 

Sorry it took so long, can't believe noone else could help. Here are the scans i promised, mainly tach specific.