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Alternator
Posted: Mon Jul 25, 2016 7:57 pm
by Tuggle
Got the filters and carbs reinstalled, running great, only to find my starboard alternator is not charging. It is my understanding this setup has a external voltage regulator, how do I determine if it is the alternator or the voltage regulator, probably both. What are the pro's and con's of switching over to a one wire system, or is it even possible? By the way which one of the engines is reverse rotation and does that matter in regards to a rebuild?
Re: Alternator
Posted: Mon Jul 25, 2016 8:21 pm
by Maestro
There is probably an easier way to test this, but to be absolutely sure about the alternator you could pull it off and take it to an auto electric shop for a bench test. Or, you could swap in the voltage regulator from your engine that IS charging and see if that does anything.
It is pretty easy to replace with a new 1 wire alternator. I did this 2 years ago and purchased a 1-wire from ARCO. They specialize in marine starters and alternators and make parts that are exact fit to Chrysler motors. You do have to make sure it is a marine alternator not automotive. The marine version has mesh screens to contain sparks, etc. The new 1-wire alternator can basically get wired directly to the battery(s) and the old second wire is capped off and no longer used.
The only con I am aware of for a 1-wire is that they will not kick in until you hit 1000rpm. This has never really caused problems for me.
Regarding your question about reverse rotation: hopefully another member can confirm but I believe the starboard motor is the reverse rotation. Pretty sure the props turn toward the outside on a twin engine

and it
does matter for a rebuild. The camshaft is different. There may be other engine components that differ as well.
Re: Alternator
Posted: Tue Jul 26, 2016 1:14 pm
by EWRice
Most of the new 1 wire 10si alternators have AC turn on regulators. This means that they fire up as soon as they spin fast enough to exceed battery voltage. I have two of the Arco units and would never go back.
Re: Alternator
Posted: Tue Jul 26, 2016 1:43 pm
by ericinga
You can test the regulator by placing a jumper wire between the power and field wires on the alternator plug. Start the motor. If you have voltage at the dash meter, the regulator is bad.
You can have my spare voltage regulator from the 28. It was converted to one wire by the previous owner. He left the spare regulator on board. If you're near Port Royale, we can work out an exchange. I'll be at the marina Tuesday and Wednesday night finishing up the port motor.
I even have a spare 35AMP alternator that needs home.
The only internal difference between standard and counter rotation engines in the camshaft. Melling still makes both stock cams for the 318.
Re: Alternator
Posted: Tue Jul 26, 2016 6:09 pm
by Tuggle
Eric appreciate the offer of the regulator but think I'm going to bite the bullet and replace both with Arco's. Spoke with them today and they walked me through the conversion, not much to it. By the way we're down in Flat Creek, last cove on the left just past FC9, drop by.
Re: Alternator
Posted: Wed Jul 27, 2016 6:59 am
by ericinga
Huh. I was just back there on the Balus Creek side of the bay working on a Monterrey last weekend. Our son likes the little "beach" across from PR at the mouth of FC. I'll have to wander back and look for you. Send me your phone number.
Re: Alternator
Posted: Wed Jul 27, 2016 7:26 am
by barkleydave
Running ARCO 10 years no problems
Re: Alternator
Posted: Fri Aug 05, 2016 5:16 am
by Robl
I'm running a pair of these, cheap and work great. I have a large house battery bank and a pretty large stereo so I want a higher amp output. I did run a larger power wire from the alternator however.
Db Electrical HO-ADR0395 Marine Alt 105 AMP Alternator for One Wire Marine Omc Prestolite 105 Amp
https://www.amazon.com/dp/B008R23E7O/re ... Pxb1SJQYD3