Does anyone know which of the two wires at the Alternator is the tac signal? My tac does not work (has not for the last 15,000Kms) but charges fine, I removed the alt and found one of the pins burnt & the bearings sounded dry/rough, so I took the alt in and had it rebuilt (80$) but alas it still no worky. The tac does work because I tried my dash in another truck.
I don't suspose anyone has a wiring diagram on this, or know of any places the wire is likely to be broke?
Thanks
Nick

The white one.

I checked the white wire and have an AC signal that increases with RPM, so likely I have a break in the wire before the dash, anyone have a wiring diagram?? for the back if the dash?
Nick

I would double check the wire at the plug first. Mine broke where it bends over the connecter. It is possible to have enough strands of wire to get a voltmeter read but not enough to carry the tach. I had to take the weather pack apart and shorten the leads by 1/2 in. at the plug. It's been working great ever since then(almost 2 years)

Well I finially dove into the electrical to find the problem with the TAC and besides the pin being near burnt off the plug was quite meltled(at Alt) as well. I removed the dash to look for the White Tac wire and could not get continuity between it and the white wire at the alt plug, at first I thought there might be 2 white wires but after a little wire probing I found I had continuity with the alt plug white and a brown wire:eek: . so I climbed under the dash and found 18 inches of melted and bare wires!! there is a bolt on bracket under there that has a metal hanger to hold up the harness. near as I can fiqure it chafed thru and melted everything from the bracket to the firewall., for as much damage that there was everything else worked fine. I ended up replacing the wire from the back of the dash all the way to the alt, I'm happy to say my TAC now works just fine:) :)

Again thanks to Chrisk1500 for the link to electrical diagrams!!

Nick

great another happy owner :)