Just got finished installing a tach in my instrument cluster without permanent modification. I couldn't find a good spot for a larger tach so I measured and ordered a 2 1/16" Tach from Autometer to fit behind the open spot in my cluster. I took a deep breath and hoped it would work as I cut the tach bezel and lens from the body. Fit pretty good and fabbed up a U bracket that attached to both sides of the opening with factory screws and captured the 2 studs on the back of the tach.
Wiring was easier than I thought. On my factory fuse box, there is a slot marked "Acc." that is hooked to hot. On the back is a male brass terminal. I soldered up a packard connection to the red wire and plugged it in. Already had a 2A fuse in it.
For the tach light, I wired it right to the cluster ground strip and hot strip for the factory lights. Ran the green and black into the engine compartment, grounded the black and hooked the green to coil (-).
Works perfectly. I may try the green light cover to see how it looks
Wiring was easier than I thought. On my factory fuse box, there is a slot marked "Acc." that is hooked to hot. On the back is a male brass terminal. I soldered up a packard connection to the red wire and plugged it in. Already had a 2A fuse in it.
For the tach light, I wired it right to the cluster ground strip and hot strip for the factory lights. Ran the green and black into the engine compartment, grounded the black and hooked the green to coil (-).
Works perfectly. I may try the green light cover to see how it looks