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TR6 71 TR6 Alternator Wiring

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brent615

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I have found a brown/yellow wire hanging loose below my alternator. Dan Master's diagram shows it connected to the alternator in two places but my alternator is slighlty different than the one he shows. I currently have two wires connected to the alternator - one marked BAT and the other FLO. Beyond that I have a GRD (ground) post with no ground connected, a post marked STA with nothing connected and a third post with no designation.

Question 1 - do I NEED a ground?

Question 2 - which 2 of these three post should the brown/yellow wire connect to? My ignition light stays on all the time and I think this wire has something to do with that.

I'll try to post a pic since there is no obvious bradn LUCAS GM etc. visible on the alternator.

Thanks
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I'm 99% certain that is a Ford Motorcraft alternator that requires an external regulator. I have the same unit on my TR3A. Not sure of the wiring offhand, as I sourced the harness from the alternator to the regulator from the same junked car I got the alternator & regulator from.
'STA' stands for "stator", it's a low-voltage AC output that the regulator uses to decide when to apply field current (and turn off the dash light, which should be wired to it's output on the regulator).

The brown/yellow wire is the line to the dash lamp, which should be connected to the regulator as above. On my TR3A, with that alternator, I also added a resistor across the dash lamp, to help the alternator get started when the engine was first started. Without the resistor, I had to deliberately rev the engine to get the light to go out, which was kind of an annoyance.

A ground wire is not essential if you don't use a rubber mount, as the mount will normally provide a good enough ground. However, I added a ground wire to mine, just as insurance. ISTR there was also a ground wire to the regulator from the alternator, but I'm not positive about that offhand.

PS, might be easiest to switch to an internally regulated alternator; but if you opt to keep that one, I would suggest picking up the wiring harness from the junkyard as I did; including the special connector for the regulator. If you don't want to do that either, let me know & I'll look at the wiring on the TR3A for you.
 
Thanks. I have a "connector block" mounted in the engine compartment on teh drivers side fender. It has 4 connectors but only 2 are in use. One green wire from the fuse box to the connector block, the other from the connector block to the alternator (yellow, w/blue tab in pic above)

I'll see what I can find locally or online for the Ford Motorcraft set up. I'm sure my local mechanic can tell but its Sunday and I am impatient. Not to mention a little prideful when it comes to being able to say I did it myself.
 
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