Searched here and there is information but the wire colors are different. Colors are red, black, white. Other suggestions here stated: white - ground black - 12volt source green - neg terminal on coil. Tried the white and black as above with the red to the coil but no luck. With the white and black swaped it works but the tach back light pulses. Anyone with such a tach out there? Thanks for any help.
most of our tach's are made by vdo. here's a pdf on proper vdo tach installation: hope this helps http://www.egauges.com/pdf/vdo/0-515-010-516.pdf
Here is the Turlock swap meet tach. There is plenty of info on line for 3 wire tachs, just not for the colors on this unit. So, thought I'd ask before frying it with the wrong connection.
My EZ wiring manual lists the coil wire as purple or white. The wire color in their harness is purple. Why they list white I can not say, but I find it interesting that they even mention white.
I have one of those same old Napa/Balkamp tachs as you have in your photo except mine is a 8k rpm version. My three wires are green, black, and white. The guy I got it from had labeled the green as distributor, black wire as ignition/+, and white as ground/-. In your case I would substitute the red for ignition/+.
Well, took the tach apart while watching the 49rs (Superbowl) play catch up. Inside was a number; 3-5660. The white wire looked more like a faded green inside and it was soldered to the circuit board. The black and red wire went directly to the light bulb socket (single terminal bulb connector ohmed out to the red wire). There was another black wire soldered to the bulb socket and it went to the circuit board. Hooked it up to the vehicle per the following and it seemed to work fine. Posted this for anyones future reference. Red wire - 12volt source Black wire - ground White (green) wire - coil terminal