m455sx

Ever since i got the car in June of 2010 the lights in the tach do not work. I pulled the tach out last night and i checked all wiring going to the tach with a test light that i have power going to the unit. I changed the bulbs clean the the areas that needed for concact and lights still do not work. Any suggestions???

MDchanic

Do you have power coming from the plug on the harness?

- Eric

m455sx

Yes there is power coming from both wires going to the tach, orange one is for the clock and gray one for the lights.

allyolds68

Is the ground wire attached?

Did you bench test the whole unit when it was out?

If so did you bench test each bulb to make sure they worked?

m455sx

Ground wire? As per manual no ground wire listed or shown, I have tested bulbs with multi-meter. I have a hard time with electrical so please be patient!!! It seems to be self grounding. Would the clock and tach work with no ground? Please explain the best way to bench test.

allyolds68

On a 68-69 there's a ground wire that that grounds the body of the tach. It's a jumper wire from the speedo. I don't know if your's has that but in order for the lights (or the clock) to work the unit has to be grounded.

With the tach out of the car simply run a wire from the negative on your battery to the steel body of the tach and another wire from the positive terminal to the light feed and see if the lights work. If they don't light up then remove the bulbs and test them individually.

m455sx

I will bench test the unit tonight. I have already tested the bulbsand they are fine.

m455sx

bench tested and not working. Cleaned contacts with Emory cloth and the lights work very well.

MDchanic

Alright, we need some photographs here.

If I am not mistaken, there is essentially nothing to the wiring on these units - a few short wires and that's it.

You've just got to test each part of the circuit until you find the place where the electricity stops.

- Eric

m455sx

Hey man a day late and a dollar short!! Gauge pod was installed asap once light bulbs were working. Maybe pictures next time.

Allan R

Eric, you'd be right on that. The 70-72 rallye pac is simple wiring. Most of the ground issues are from the metal strips fixed to the dash that the pod bolts go through to get