I should know how to do this... But for some reason I don't. Most tachs have a power wire comming in, ground, and input from the negative post of the coil. what am I missing? Been through ten pages of search for unilite and no mention of tach hook up... Help please!
Contact Mallory with your issue. I have heard with some tach you may have to run a resistor because of the higher voltage tach signal. It just something I heard never tried it.
I have an original early 60's one piece 10,000 Sun RPM tach in my 55 Chevy, with a Unilite dist. The tach is hooked up the same as it was, when I still ran a stock Chevy points dist. I'd have to look to see what the actual connections are, though. After over 10 years, niether the tach or the Unilite have caused problems. It also has a stock, repro wiring harness with a generator. Not an alternator. Besides the wires that you mentioned, isn't the only other tach wire, the one for the gauge light?
If it is just a standard 3 wire tach the positive will come from an ignition on source, the ground is just that, and the signal will come from the negative post on the coil. We are running 3 Unilites and that is the way all our tachs are wired. Don
Been awhile, but I think so. Might be a fifth wire for ground for the light too. Seemed like when I hooked up the ground it was grounding the ignition itself. Wouldn't run untill I detached the ground for the tach... I think I killed the module.
Now that you mention it. The gauge light does have it's own ground wire, because it has a plastic light socket. Also, Mallory sells a surge protector for Unilites, now. Plus, a word of warning for anyone using the new "SunPro" 60's style tachs. Make sure that the electrical posts on the back of the tach don't short out on the tach cup. This happened when my older brother installed one of these tachs in his 57 Chevy. All he had to do was trim the posts down a bit.....And replace the module in the Unilite. That is how he found out about the surge protectors. When the tach shorted out, it fried his brand new Unilite.
Are u sure the tach itself works.I have a tach hooked 2 a unilite and is wired the way u said,mine works fine
It hooks up just like any other tach to any other ignition. Switched hot, ground and one wire to the negative side of the coil. It has no idea if you are running a Malory, A/C Delco , or ACCEL.
Damn good possibility that the tach is junk then. Took out the module too... ****. I was thinking along the lines of the M.S.D.s and things like that that have a separate out put for the tach, I'm not too familure with Unilites and wondered what I was missing. Thanks guys!
Are you only using a coil or are you using an ignition box? If you are using just a distributor, and a coil, you wire it as everyone here has said. If you are using an ignition box like a MSD 6A or a Mallory Hyfire6, etc, then the box will have a tach output that will trigger the gauge. Brian
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