What is wrong with your tach? Do you only need to hook it up? You can check the meter movement by connecting an ohmmeter across the terminals, observing polarity- the ohmmeter will read several hundred ohms and the needle will show something on the RPM scale. Set the ohmmeter to the lowest range, so as not to apply the higher voltage that comes with the higher ranges. If the meter movement works, the trouble is either with the connections or in the transmitter itself. The transmitter is the box that connects to the ignition system and drives the meter movement. The connections on the transmitter are distributor or coil negative terminal, ground (I think), and meter + and -. I believe they are all marked. If you reverse the meter connections and all else is all right, the meter will read backwards. The transmitter has a battery inside, which probably is dead by now. I don't know the type, but I believe it is a 'coin' type, probably nickle-cadmium. I don't remember if there is an access cover for the battery, or if you have to take the transmitter cover off- I think you have to take the cover off. There is or may be a relay inside the transmitter that may also be causing trouble, but the transmitters are usually pretty durable. I don't think I have a schematic of the transmitter; if I do, I doubt I could find it.
If the meter movement itself needs repair, find an aircraft instrument repair shop- they can repair that type of meter movement, but it will probably cost you a small fortune for their attention. The meter is a common D'Arsonval moving coil movement, made by practically every instrument maker in the world, but now replaced by less expensive movements or by digital circuits. An old watch repair man might be able to repair it, depending on what happened to it. A common failure was/is for the axle to come loose from the coil, then the movement quits moving; but an instrument or watch repair man can correct that without trouble, and adjust the bearings properly.
Or you can probably find someplace advertising on the Internet that can do that kind of repair.
There may be other ways to handle this, depending on what is wrong with the setup.
Hope this helps. Keep in touch.
Harvester
