‘89 F-350 460, ZF5

Need some help with this wire…

So..installed VHX Dakota digital gauge set. Got it all installed and wired up. Fired it up (new engine build as well), and seen it’s not charging. 12.3V at the battery. Was planning on upgrading to the 3G alt anyways in the future, so went ahead and did that since I thought the alt was bad. Still not charging.
Remembered that the sense wire needs voltage to turn on the alternator, so tested that for voltage. No voltage. Hmm…jumped 12V to the alternator side of sense wire (GN/R), and it charges at 14.8V max. (Made up 1/0 charge cables with a 150A mega fuse inline to starter solenoid.)

It looks like R/GN wire goes into cluster, presumably goes through bulb/resistor combo, and sends voltage through GN/R wire. I attempted to jumper R/Y wire (most convenient to get to; hot in run) to GN/R, but still get nothing at connector coming out of harness and to alternator plug.

-How much Voltage is supposed to run through the GN/R sense wire? I’ve read 12V will eventually burn out the Voltage regulator….

-Does the GN/R wire go straight to the alternator, or is there a fuse/fuse link for it somewhere?

-Thought about tapping into solenoid start wire, but I’m not sure if that’s a good idea…

Hope this all makes sense..

Frank

 

The green/red needs a 12v signal wire any time the key is in run. As soon as you lose this 12v, it will quit charging. So the start solenoid wire won't work.

I would buy a nice 12v panel light and find a place to mount it. It must have two wires to the socket, the socket cannot be the grounding type. Find your 12v that runs your gauges, or some other key on 12v source, run it to the light, and then hook the green/red to the other side of the light.

The light is handy to have when you throw a belt, when the engine stalls for some reason, it has more uses than just telling you the alternator is charging.