Your new one wire alt. will not use your existing regulator or wiring.

You will need to run a wire (appropriate size to handle the maximum amp rating of the alt) through a fuse (again large enough to handle the amperage of the alt.) then directly to the battery you are charging. The in line fuse should be within a couple of feet from the battery.

High amerage fuse's are availabe on line. I installed 60 amp alts five years ago on my and they work great. They do require a min. of 1,000 rpms to activate the internal regulator.

You can run a seperate ground wire but usually the bracket bolted to the block works fine.

safe boating,

dave

That's how the previous owner did it on mine.

Jeff

ARCO 40112.

Doug is right on as always!

Mine came from Masco and where nice folks to deal with.

I went with 8 AWG and there was no ground stud on the ones I received. I made sure I had very clean contacts with alt. bracket and block and used dielectric grease.

Mine have run flawlessly for 5 years now. I was not able to locate orange 8 awg so went with red. I used 80 amp Maxi Fuse inline fuse which is has a rubber cover. If you need to go to high amps then move up to an ANL fuse which is what I used when I installed by 1800 watt Xantrex Inverter a few years ago.

https://www.vtewarehouse.../html/maxi/maxifuse.php



dave

OK, got it all put back in and did NOT run the ground wire. Charging system worked great and was even providing good voltage at idle (advantage of the 1 wire system I guess). So I let it run in the slip for a while and came back. Voltage was now bouncing around between nothing and 14V. Is this a symptom of a bad ground? I was out of time and had allready taken everything back to the truck so I din't have a jumper wire with me to try and get a good ground to the alternator.

Doug, I ran the battery wire back to the factory location on the input side of the solenoid on the back of the motor. And it worked! For about 30 minutes that is... Then I see the voltage gauge bouncing around but knew it wasn't to be trusted. So I turned on the battery monitor that goes directly to the battery and the rythm matched the gauge on the dash. I always had voltage but it was between actual battery voltage and charging voltage (12.7-14.7) and came and went very erraticaly.

Went back to the boat today with meter and jumper wire in hand. Started the engine and could never get the system to do it again. It was charging normally. I just love it when problems magic themselves away. Typically that means it's waiting for the worst possible moment to show itself again.

Jeff, I have a battery monitor that feeds directly off each battery and it was doing a dance identical to the voltage gauge on the dash so I have no clue what's going on unless it's a problem with the switch or a battery connection that comes and goes with vibration and heat.

Dave, that's correct. The meter coming straight off the battery was in perfect synch with the gauge on the dash.

When you are checking voltage at the battery, be sure to put your probes directly onto the top of the battery posts. You want to get the actual voltage that the battery sees, and it may be different from the voltage at the clamps. I just saw a case on an M where a battery was showing a nice charge voltage at the terminals, but the actual charge at the battery posts was nil. This, of course, is caused by bad contact between terminal (clamp) and battery post.

You should have a multimeter (digital voltmeter) with long leads with clips, so that you can clip onto the alternator frame and check voltage drop from there to the negative battery post, or to clip onto the POS alternator terminal to measure drop from there to the positive battery post. These measurements will tell you if you have a problem in the wiring. More than a tenth of a volt is probably too much.

It is hard to buy long meter leads. If you ask for them at Radio Shack you will get a blank stare. But they are very useful. You might want to make your own with wire and alligator clips that you can get at Radio Shack.