Due to my recent/ongoing alternator troubles on the wife's truck, I installed an extra alternator that so far is doing the job without YET killing any regulators.

This truck came from the original owner equipped with a VDO tachometer that connects to a wire hanging out the rear of the alternator.

Of course, the other alternator I installed lacks this tachometer wire.


The plan is to pull the cover off both alternators, figure out where this wire is connected, and install a like wire into the good alternator.

What am I going to find in there ??

Can I simply ring-terminal this tachometer wire under a friendly screw inside there; or, am I going to have to identify and solder into some "winding" wire ??


Thanks.

 

BearKiller I feel your pain. I can't help ya with your alternator/tach problem, but i'd offer you a beer if you didn't live so far away. You have gone thru some stuff on alternator problems. Hope it turns out simple for ya cause you have worked your ears off on this problem. Good luck.

 

if i got my alternator theory correct.... i think you need to tap off one of your phases before the rectifier bridged. all the tach does is read the sine wave created by the alternator. im pretty sure but hopefully someone else will chime in..

 

You need to make a W wire. I think bradshaw hit it right on the head. If you see an alternator with a "W" terminal thats what it is for. I have had boats before that used that style of tach.

 

Thanks for the replies.

I took the back cover off the alternator that already had the tach wire and it was not near so mysterious as it could have been.


I made up a short tail of 14AWG, with a #8 un-insulated ring-terminal on the alternator end, and a female spade on the outside end.

To protect from sharp edges, I covered the whole length with three layers of heat-shrink, with a fourth layer in the area that comes through the slot in the cover.

A flexible insulator covers the female spade.


Just like the man said, I simply put the ring-terminal over the nearest screw that holds one of the stator circuits and tightened it back snug, then routed the wire out through the little slot in the cover.

Tach works as good as ever.


Thanks.