Merc 3.7/470 voltage reg

[Reelrazor]

I know people are going to chime in and say “ just put an alternator kit on it”.
the low mount doesn’t work for me-no room in front of crank pulley. Has power steering pump so high location is already occupied.
I’ve been a powersports tech for more years than I care to admit. ( motorcycle, SxS, etc). Stators and reg/rect is the norm for me. Testing is easy and packaging is compact. A bolt on alternator is the EXACT same system that takes extra mounts and a belt to drive it.
So, I lost charging while we were out waterskiing (‘87 Sea Ray Seville with 165hp 3.7).
we continued our evening skiing and then got it back on the trailer.
30 seconds of testing determined the stator was fine ( 25VAC at idle—no continuity to ground). So, off to order Reg/rect. Daaaammmnnn. $447??!!.
Look at it, water cooled, rectifies AC, regulate to 14.4VDC…40amp max.
Screw that. Look at the big base/mount. I can work with that. I can give you details, or I can do this for you.

 

[Bt Doctur]

there is a low mount 100 amp that uses your exising balancer pully groove

 

[Bt Doctur]

LITRE MERCRUISER ALTERNATOR KIT 488 470 170 165 P.S STATOR REPLACEMENT | eBay

FREE ONE YEAR WARRANTY ! ONE YEAR WARRANTY.

www.ebay.com

 

[Eric 3.7LX Alpha 1]

Okay, give us some details. You modified the VR with something else....

 

[Reelrazor]

Okay, give us some details. You modified the VR with something else....

I used the stock reg/mount. Depotted the old circuit board and installed a modern MOSFET 39amp reg/rect. All in, far less than new OEM style. reg/rect. Still uses the water cooled heat sink.
13.2 VDC at idle. 14.3 VDC at full revs.
no discernible heat. 9 hours run time since conversion.

 

[Reelrazor]

there is a low mount 100 amp that uses your exising balancer pully groove

Yeah. Looked at that link. it’s $329. and my power steering is already using that groove. My experience says that the <60° Belt wrap that results WILL prove problematic at some point. Plus, I have seat base and doghouse corner occupying that space. Fuel tank in floor just in front of crank pulley.

 

[Eric 3.7LX Alpha 1]

The kit BT posted was about $350.00 incl. shipping.

What kind of money is your conversion and what part did you use? What were the steps to convert it? You may be able to help others down the road that would like to keep that set up.

The only flaw I see is your limited with the output being low like the factory set up. Which is fine for a mid '80's boat with '80's technology. With all the electronics people are doing today, big screen chartplotters, radios, fishfinders, radar, VHF, I think I feel more comfortable with the higher output of the belt driven alt, even though I did like the simplicity of the factory setup without the belt to deal with. I bought the voltage regulator once, when it failed a 2nd time I went with an alternator.

 

[Reelrazor]

The kit BT posted was about $350.00 incl. shipping.

What kind of money is your conversion and what part did you use? What were the steps to convert it? You may be able to help others down the road that would like to keep that set up.

The only flaw I see is your limited with the output being low like the factory set up. Which is fine for a mid '80's boat with '80's technology. With all the electronics people are doing today, big screen chartplotters, radios, fishfinders, radar, VHF, I think I feel more comfortable with the higher output of the belt driven alt, even though I did like the simplicity of the factory setup without the belt to deal with. I bought the voltage regulator once, when it failed a 2nd time I went with an alternator.

Big starting battery. Big deep cycle accessories battery. Really the only way to go if you’re going to run a ton of load regardless. 40amps more than enough to reach ‘break even’.
I’m $74 in pocket, and about two hours total of my time (r&r-de pot, sand to bare metal, drill four holes, coat with thermal paste)
it’s a modern replacement for a mid 90s Harley with single phase 39 amp stator. ZERO change to stock wiring.
I’d sell the whole setup ready to bolt on for $350.

 

[Reelrazor]

The kit BT posted was about $350.00 incl. shipping.

What kind of money is your conversion and what part did you use? What were the steps to convert it? You may be able to help others down the road that would like to keep that set up.

The only flaw I see is your limited with the output being low like the factory set up. Which is fine for a mid '80's boat with '80's technology. With all the electronics people are doing today, big screen chartplotters, radios, fishfinders, radar, VHF, I think I feel more comfortable with the higher output of the belt driven alt, even though I did like the simplicity of the factory setup without the belt to deal with. I bought the voltage regulator once, when it failed a 2nd time I went with an alternator.

Always the option to have the stator rewound ( $140) for three phase delta, and increase output and go to three phase rect/reg on same mount pattern.