THe original tach arrived for my 71! How to wire it???

The tach, I assume, is from a 70 as it has the pointed lense on it. I have the wiring harness that came from the reproduction tach. It has two wires. One from the coil to one lead, a second wire/lead that runs to the fusebox. The tach has a lead for one wire.

How do I wire it?

Thanks!

 

One wire that goes from the tach to neg side of the coil on original cars this is a brown wire not sure if there is a light in there or not I need to grab my tach and look

 

I seem to remember it just uses the same wire/socket/light that the clock would have used.

 

The lights are the same tach or clock. The manual shows only the brown wire leading to the (-) coil.

 

The factory tach used a metal strap (for lack of a better description) that bridged the tach to the speedo for a ground. Spade post on back of tach goes to coil.

 

Makes sense. Thank You!

 

>>I didn't have the metal strap when putting the original indash tach in my Buick so I ran a seperate ground wire to the dash and secured it to the tach under one of the screws.

 

You can make one of those ground straps very easily by using a piec of metal flashing and some tin snips. Drill two holes and attach it under the nuts on the dash bezel. It's easy.

 

Even I can do that!!!

 

Well here's the wrap up. Fabbed up the strap and still no go.

Ran out to Instrument Services in Roscoe, IL. They checked it out and the motherboard was bad. Had it replaced.

Home, installed, works fine. Just a larger dent in the wallet.

 

How much to replace the Motherboard?

 

$257.88

 

For some reason, I think the lights for the clock/tach are on the same circuit as the radio. If the fuse is blown for the radio, I don't think the guage will be lit at night. I really don't know, my car has no radio right now, or a fuse for it...

KFD

 

How about a picture of it mounted?

 

I can repair original circuit boards for $30 or so. Just finished with Larrys.

I can repair aftermarket ones for well under $50. FYI

 

Ouch... I wish I knew that before.

Thanks for the heads up.

 

Thye should replace the father board as well for that.ou:

 

Well that's my fault as I only recently have disclosed publicly that I provide this.