what's up everyone, just got my new tach in the mail yesterday and i am anxious to get it working. the only problem is i need a little help. the tach is made by ractive and has 4 wires. 3 of them i know where they go, 1 to battery 1 to ground and 1 to ignition and i can do all that fairly easily. the problem i am having is with the 4th wire. it is the wire that hooks up to the negative side of the coil or the tach terminal. so i was wondering if anyone who has done an auxilary tach install on a first gen could help me with where that wire should go to read the rpm's of the engine. i have seen some pics of people on here with first gens that have tachs installed so hopefully you can give me some help. thanks.

 

i've done it, it's easy. you run the fourth wire through the firewall. the ignition coil has the one wire that runs to the distributor. also coming out of it is a plug, with 2 wires. one is +, one is -. you gotta tap into the negative. generally the negative wire is the thinner wire with a stripe on it. good luck