I have a 1972 Ford F-100 with a 302 out of a 1964 1/2 mustang. How do I hook up a tachometer? It is a mini acrotach. It has a red wire, a green wire a black wire and a white wire. I f you know how or have a wiring diagram please give me some info.

 

Hi Joe and welcome to the site!

Here's how to hook it up:

Red wire to +12V switched power

Green wire to coil negative (-) post

Black wire to ground

White wire to dash light power

If you like old tachs, here's a neat site:

http://www.musclecartachs.com/docs/references.htm

Barry

 

Thanks, but im only 14, I know what the ground is and i know how to hook it up to the coil (thanks to you) but the switched 12v is kinda confusin me. and where is the dash light power so i can hook it up.

 

Sorry about that Joe. You can get the switched 12V and dash light power from the fuse box. There are two spade lugs there next to the fuses that you can tap out of (nice of Ford to do that). The upper spade lug is the switched power and the lower spade lug is the dash power. Or you could tap out of the radio harness and get the same thing but you would need a test light to determine which is which. The choice is yours, I'd buy a couple of push-on connectors for the spade lugs and go that way unless you don't mind tapping into your existing radio harness.

Barry

 

Oh.....I see what you mean now. Thanks alot. Me and my dad couldnt figure out the wires. He's got a 1969 Ford f-100. Thank you so very much.

 

okay, couldnt get it to work at 1st, open the back and seen the switch was on 4 banger, so i switched it to 8 and plan on hooking it up tomorrow. i have a question, am i supposed to hook the green wire up to the coil or the distributor??

 

Yes and yes! The green wire goes to the coil - which is the same place the wire from the distributor goes.

 

ok, ok, now, can i just take the bare wire and take out the fuse and put them in together, like with the metal touching, and do that for the switched power, and the dash light power. now, is it nessecary to have the dash light power??? and do you have to have the same size wire as the tach...ok one more, do i touch it to the neg. coil post or the post with the distributor wire on it??

 

Bare wire? Fuse? Not sure what you are talking about.

You can take the red wire and twist it together with the white wire and then go to the fuse box. The tach light will always be on when it's running, no big deal.

Now, the neg. coil post and the post with the distributor wire are the same post. If your distributor wire is going to the coil positive post, the coil is hooked up backwards.

 

but the tach dont have a light. so does that mean i dont need the dash power??and the bear wire thing..... take the end of the wire and strip a piece off about an inch long, now take out one side of the fuse slip the wire in there and put the fuse back in, so the wire and the fuse will be in there together.

 

i perfer to have all my gauges hooked into the dash lights, that way when you dim your dash lights the gauges dim too. otherwise they will be on fully all the time. hard to get romantic when the tach in blazing everything lol

 

ok, big problem...i hooked up the ground and twisted the 12v and dash light together and put it into the dome and cigar fuse and put the green wire on the neg. coil post. then my yruck wouldnt crank. i took off the wire on the coil and it crunk rite up. i put it back on there and it wouldnt crank. is there something wrong?? the lights will lite up on the tach when it goes acc, but it wont crank if i have eveything hooked up, then i broke a post off the coil, pos. so i have to get a new coil, now can someone tell me exactly where to put all of the wires?

 

You shouldn't be messing with the coil + post like I said earlier. The Green wire goes to the coil - post and the distributor wire ALSO goes to the coil - post, they both go to the SAME post. Only one wire goes to the coil + post, the original wire that was there.

Sounds like the other wires are already hooked up ok for it to work.

 

do you think it could be the coil that was bad, is that why it wouldnt crank? cuz i tried to hook a wire up to the distributor and it wouldnt crank.

oh yeah, and can i just hook up the ground anywhere? because i just loosened up a bolt holding the steering column in and tighten the bolt down on the wire.

 

Yes, a ground can go on any good metal surface.

Try it all over again with a new coil. Remember, the distributor wire goes to the coil - post and the Green tach wire ALSO goes to the coil - post. Only one wire goes to the coil + post, the original wire which is Red/Green stripe.

Did you buy this tach new?