Blown408

Ok guys, I changed combos up and need some advice if someone has done this before... I went from EFI to carb. Problem that is arising that I am going to start digging into on Sunday is getting the factory RPM tach hooked up. It was all hooked up fine until I swapped to the carb setup. My ignition consists of a 6BTM box with the 8485 MSD dizzy. Is there an easy way to track down the wires that need to be hooked up correctly before I go blow some money on a Chiltons book? I have researched this a little but the problem that I have is the car has had wire tucks and so on, so that basically means that any harnesses that you guys might point out to me are not in their stock locations anymore!! The whole wiring system has been refabbed totally. Is there a certain wire behind the dash pod that I can trace to hook up, and if so I need to know what colors and location and so on... I am also using an MSD coil. The only thing that was tore out of the car when I did the swap was the Fuel injector harness. All other wiring harnesses remain in the car. Never know if I might go back to EFI down the road so it was a good idea to leave everything in tact!! I really would still like to use the factory RPM gauge until I get the aftermarket speedo and RPM gauge this coming summer. Any help guys, I would really appreciate it so this doesnt turn into an all day venture!! Its a 93 also!!

tohoopty

i ran a wire to the back of my gauge cluster.when you pull it out.flip it over and look at the back right behind the tach.there will be a thing that says tach signal.you can see it in the pic.i highlighted the place where a wire needs to be spliced in the harness.sorry i cant explain it better but i just went outside and took a pic of a cluster i had laying around

Blown408

That is awesome bud!! I will try that tomorrow morning!!

Blown408

What is the easiest way to hook it up? Wire it to the harness right from my coil, or run it from my box?

tohoopty

well glad i could help out with the pic.im not sure of how you could run it.i got a hei dizzy on mine and i just ran a wire straight from my dizzy to the cluster

Blown408

Ok major problem here... Tried it out. I tied into the tach signal wire, ran a wire all the way back to my 6BTM tach hook up. Went to start it and nothing. The car has power in the key on position, but on the key start position I lose all power, it cuts right out. If I put the key back to the on position I have power. So thinking i hooked it up wrong I put everything back to the way that it was when I started and still having the same problem. WTF?? I did some testing on the starter solenoid switch and heres what I have. I have good power to the terminal from the battery-12V. I tested the S terninal, the thin gauge wire on the third hookup and I have no power while cranking the key. WHat could be causing this? I have no clue what in the hell to do from here. I know it is not a bad switch. Any clue guys?? give me some advice here!!

Blown408

Ok, was freaking out a little prematurely.... Got it up and going. Had a bad connection on that wire. Cleaned out the corrosion and put it back on the switch and she fired right back up!! But I still cant figure the tach situation out. I spliced into the tach wire behind the dash and ran it right into my box tach hook up. Car would crank but would not fire. So I am either going to try wiring it right into the dizzy or the coil. I am going to call MSD too to see what they have to say!!

pete88gt

you can run the tach wire off of the negative side of the coil.