alternator swap

[jcdubbu]

Quick question... I was replacing my alternator due to it being seized up and had to go with a aftermarket one. Before I ordered it I talked with company out of Minnesota they told me that the one I ordered is a direct replacement for the original unavailable one. Problem is, when I received new one it had only one insulated terminal post on the back of it whereas my original one had 2. Original one had a wire coming off each post. Can i just install both wires on the one post of the new alternator? Original alternator was a Prestolite #981187 and was replaced with a Arco Marine #40152. Just need to know if I need to call and start the return process. Thanks in advance!

 

[bigdirty]

Re: alternator swap

I don't think putting both wires on the same post is a good idea.. got pics? GM or ford alt? Not that it wont work, somehow, but you're gona have to figure out what the two wires are SUPPOSED to go to.. (one my be a signal or 'field excite' wire(?), one will be the + 12v charge wire.. may run just fine without one wire connected.. if the new alt only has one insulated post, that is the charge.

 

[bruceb58]

Re: alternator swap

One is likely the excite wire and the other is the larger charge wire that goes down to the starter. Sounds like you have a self exciting alternator now so won't need the excite wire.

What year/model drive do you have? Did it used to have an external regulator?

have a picture of the wires and the back of the old alternator?

 

[jcdubbu]

Re: alternator swap

It is a '78 seaswirl with a omc 185 in it with the elec stringer drive. here is a pic of both alternators.Hope this helps. Thanks

 

[bruceb58]

Re: alternator swap

You don't need to hook up the wire that used to go to the lower left post in your second pic. Just need to insulate it and leave it disconnected.

When you get your new alternator in, measure the voltage to make sure you are getting full charge voltage(13.5V to 14V). You may not see it reach this voltage until it gets over 1000 RPM with these self exciting alternators.