[GB SISSON]

Originally Posted by Flathead Fever

That is a neat boat, it has a lot character. I want one here in SoCal to go ocean fishing but I don't need anymore more projects.

Here are some diagrams for marine alternators. It shows the EXC terminal going to the ignition. I'm guessing "EXC" is for exciter? The "S" terminal is the stator. Ford calls it the stater pulse rev counter for tachometers. I don't know anything about that? I do know that 1965 mustangs used an idiot light wired to the regulator "S" terminal that was also wired to the "S" terminal on the alternator. The 1966 mustangs have ammeters so the "S" terminal was not used. That is what I know about the "S" terminal. It sounds like on marine alternators it powers the tach with a pulsing AC voltage. I think the "S" terminal is the one they are calling the AC tap terminal in these pictures.

I found where somebody wrote this. "Nearly all outboards made in the last 40 years use alternator (stator) driven tachs. The tach counts the A.C. pulses from the alternator. Car tachs counting primary ignition pulses won't work on them". Who knew?

https://www.jamestowndistributors.co....do?docId=1096

https://bpi.ebasicpower.com/charge/alternatorwiring.htm

Thanks very much for this info! Mine is the first one at the top. Late motorola type. It's a clone to mine. In that diagram it shows the S as a sensor wire to the +terminal on the battery. I had seen a few like this in my search and they had a simple jumper wire from the large B+ output terminal to that S terminal, but no real explanation. When previously running the engine with all the wires removed from the dead alternator the tach worked fine so the tach must be getting it's signal elsewhere. Also, no idiot light as the panel has a voltmeter. Tomorrow I will wire it just like that diagram. I knew I would get the help I needed here. Thanks so much!