yanmar alternator 2gmf

[galynd]

I'm helping my brother put a rebuilt yanmar 2gmf into his catalina. We've got the wiring figured out pretty well with the help of the schematic. However, the alternator has 4 wires to attach. Obviously the b terminal is for the pos cable and another is for grounding. However, it has a two prong plug in. My thinking is it must be to excite the alt. If so, is one side of the plugin from the key switch and the other for ground?

any help is appreciated.

 

[sailingdog]

It would help if you said what make/model alternator it was. Last I checked Yanmar doesn't make alternators. It would also help if you said whether it had an internal or external regulator, if any.

 

[sailaway78]

Yanmar alternator

If memory serves, there is a little slot on the back side, with two spade terminals in it.
The spade terminals are in a T shape. You need a plug that fits that slot and the two spade terminals for this to work right. Think it cost about 6 bucks. Thats the way mine is. Alternator is Hitachi. I think one of them is for the exciter lead, and the other one for the charge light. Any alternator shop should have it. Not sure how this set up works, but I recently changed mine out, and didn't have it right. Was getting 16+ volts. Wish I could be of more help, but thats all I can remember, and don't have any more info. with me now, and am not at home.

 

[galynd]

Re: Yanmar alternator

Nice N Easy, you are exactly right. I've had one myself and had it rebuilt to an external regulator where I didn't need the plug anymore. I'll pick up the "t" plug at the local alternator shop.
sailingdog, it is an internal reg. I have to assume it's Hitachi, as N n E says as I'm not at the boat.

So since his boat doesn't have the charge light does that wire still have to be plugged in. And the exciter....does that come from the key switch.

again, all suggestions are appreciated.

 

[Ed Schenck]

Before my new Yanmar with Balmar and external reg I had the Hitachi 50 amp alternator. I had upgraded from the original 35 amp which did not have an exciter requirement. With the newer 55 amp I just ran that exciter wire to the solenoid post on the starter. A much shorter wire then going to the key switch.

I found the old thread where we discussed this:
http://forums.hunter.sailboatowners.com/showthread.php?p=151613&highlight=hitachi wiring.

 

[Bill Roosa]

try the balmar web site

The instruction manual for their external regulators has a great wiring diagram for every make of alternator.
Typically there are +, -, regulator input, and tack output. But like others have said, it varies between alternator makes.

 

[Maine Sail]

If this is the 35 amp model with the T connector I believe the "L" terminal is the vertical part of the T and the "R" terminal is the cross portion of the T.

L term should go to charge lamp (I recall this wire being a blue with a tracer color)

R term is connected through the oil pressure circuit to excite the alt (I recall this wire to be red with a tracer color).

It's been a while but that is how I seem to remember it. Please look into this more as my memory may be a bit rusty.

I also just remembered that some of these alts did not use the "R" term and were internal excite so you may have one that only uses three wires, L, B+ & ground?

 

[druid]

I had a hellova time getting mine to work - I didn't realize you MUST ground it (with a wire capable of handling 50 amps, or course!). And the others are right about the L and R (although I connected my R straight to the ignition switch).

druid