Wiring 2 post alternator to 3 wire wiring harness

[Bakersfieldboater]

I'm trying to wire a two post alternator to a three wire wiring harness on my 87 Seaswirl spider. The OEM alternator had a charge post, excite, and solinoid post. The new alternator has an excite and charge, but no solinoid post. Any suggestion on how to complete this installation.<br /><br />Thanks

 

[Bakersfieldboater]

Re: Wiring 2 post alternator to 3 wire wiring harness

I'm leaving for a three day camping trip this evening, so any suggestions or wiring schematics would be greatly appreciated.<br /><br />Thank you

 

[tommays]

Re: Wiring 2 post alternator to 3 wire wiring harness

i may be worng but there should only be 3 wire or 1 wire alts<br /><br />the newer 1 wire takes your battery wire and the second wire is usually a case ground<br /><br />there should be instrutions with the new one <br /><br />you would tape up the extra hot wires<br /><br />tommays

 

[Bakersfieldboater]

Re: Wiring 2 post alternator to 3 wire wiring harness

I had three wires to install; battery charge, excite, and solenoid. The new alternator had a charge and excite, but no solenoid. I called around and was told the solenoid lead is a reference voltage and may or may not be needed.<br /><br />So I installed the charge and excite and boat started and ran fine, but when the key switch was turned off the boat continued to run. Turns out the alternator was back feeding the key switch and keeping it open. So, I installed a diode inline on the excite wire and everything works correctly now. <br /><br />The only thing that I am noticing is my oil pressure gauge fluctuates a little and it didn't use to. Could this be do to the solenoid wire not being connected?<br /><br />If you have any suggestions on what to do with the solinoid wire please let me know.<br /><br />Thanks for you help.

 

[navigator336]

Re: Wiring 2 post alternator to 3 wire wiring harness

A one wire alternator shouldn't have an "excite". Try disconnecting the excite wire and see if you charge. This obviously will prevent the run-on condition since there won't be any connection back to the I terminal on the ignition switch.<br /><br />Is this a rebuilt alternator? If so, possibly it was rebuilt as a single wire but the case was originally a three wire.