I found a tach cluster from an 87 firebird donor car. Other than the cluster itself and the cover plate, what else do I need to grab to make it work in my 87 firebird? (Any of the wiring?)

 

Are you replacing the old tach, or adding it as a new tach?

 

I am converting from the ugly style with the dollar sized circles to the tach setup.

 

So you currently have an idiot light dash? You'll probably need the VehicleSpeedSensor, and the VSS buffer. Crawl under your car from the driver's side and look at the tailshaft of your transmission. There will either be a thick cable coming out, or a plastic connector with wires (covered by a wire loom). If you've got a plastic connector with wires, you already have a VSS sensor and buffer.

If you've got the cable, you've got the cable driven speedo, so you'll need to pull the sensor (one bolt) and buffer from the donor car.

The VSS buffer is bolted next to the computer. Remove the panel at the bottom of the dash, on the passenger side, that faces the passenger. (Not sure of the proper name, sorry) I don't mean the hush panel (black panel above the passenger's feet), or the kick panel (to the right of the passenger's feet).

Once that panel's removed, you'll see a relay (or two) for the rear defroster (and power antenna). In that area is a yellow box, that's the VSS buffer, grab it and it's bracket.

To pull the VSS sensor, just crawl under the donor car, remove the bolt, and pull the sensor out- then get out of the way!! Trans fluid is going to POUR out of that hole. Stuff it with a rag to save the environment and so you don't tick off the junkyard owner.

Also get the VSS wires. Might as well! If the trans is an automatic, the VSS wires actually join with the TCC (Torque convertor clutch) wires. So from under the hood, find the VSS/TCC loom- it'll spiral down from the driver's side of the engine, Way at the back, by the distributor. Cut all the wires (with automatic trans, there should be 6 in that loom). Unclip the VSS connector from under the car. Unclip the TCC connector, this will be on the driver's side of the trans, up "above" the driver's side of the trans fluid pan. Now while you're still under the car, pull the two connectors away from the engine- you should be able to take the whole harness with you.

As for wiring it up, well, that's as far as I know. I pulled this stuff from a junkyard car in case I ever needed it.

Is the donor car a v6?

 

It's a V6 tach for my V6 car. So if my car has the buffer and sensor already, then i don't need anything else?