Factory Tach Install Question

[frankslagoon]

I installed a new in dash tach in the 63. But no worky.
Pink wire to ign. same hot wires as old tach at fuse box.
gray wire to dash lights. same plug as old tach at fuse box.
Brn. wire to neg. - side of coil. same as old tach.
Pink wire to + side of gauge.
Brn wire to - side of gauge.
I marked the backing plate to match terminals on the gauge before I put it in the dash. pos. side to pass. side and neg. side to drivers side
I think my dash is a 62 c 30 full gauge type. maybe I marked the terminals wrong ?
You guys see anything wrong ?

[hotrod66]

Original or repop? Because the originals required a under hood box like the old Sun tach.

[frankslagoon]

Repo like lmc and classic sell

[ray_mcavoy]

All of the factory 60-66 tachs were made by Sun and are physically interchangeable among all 60-66 Chevy truck full gauge clusters.

The 60-62 tachs did use a separate transmitter / sending unit box.

But the 63-66 tachs were self-contained and no longer required the separate box. I believe the reproduction tachometers are a copy of this style.


The first thing I would recommend checking is the ground. I don't know for sure about the reproductions, but the factory 63-66 tachs ground via contact with the backing plate. And the backing plate is in turn grounded to the cluster case. If you painted the backing plate it might be interfering with the ground.

Originally Posted by frankslagoon

Pink wire to + side of gauge.
Brn wire to - side of gauge.
I marked the backing plate to match terminals on the gauge before I put it in the dash. pos. side to pass. side and neg. side to drivers side.

The terminal markings on the repro tachs must be a little different. It sounds like they're in the same orientation though. The factory 63-66 tach terminals are marked "Ign Sw" for the pink wire (pass side) and "Dist" for the brown wire (driver side).

[frankslagoon]

Yea ok i put jumper on as ground to the cab i'll figure it out

[frankslagoon]

I figured it out. the gauge has a rivet that holds the ground trap on the back. when I tighten the gauge into the backing plate the rivet gets pushed into the gauge hard enough to short out something in the circuit board inside the tach I quess. I used a rivet washer between the gauge and the backing plate on each side and works good now. ?