Alternator advice - '85 Mercruiser 170

scook · #1 04-21-2015, 12:18 AM

This is the integral one. The stator is shorted to ground / the commutator looks very good / rhe voltage regulator tested good as far as I went. Assuming it checks out OK, would you suggest a new stator at around $200 or changing to an external alternator for the same or a little more money?

If an external one, what brands are reliable? On another forum, some 170 guys liked a kit by Breezeworks (they sell a 3-wire alternator in their kit). If I go for a 1-wire, how do I know it's a true 1-wire and will charge at low RPM? I'm short on time, so need a kit with all the parts - I don't have time to fab anything right now.

Any help is appreciated - thanks.

spareparts · #2 04-21-2015, 06:46 AM

make sure you have room for the alternator, not knowing how big your engine compartment is, but the alternator kits I've seen take up a lot of room in front of the engine and to the starboard side, if you don't have room, then the decision is easy. I haven't done a swap over in a long while, so I'm probably out of date on the offerings. I've got a 25 Bertram that I'm helping a friend with that has two 3.7L mercruiser v drives in it, we are going to swap out the charging system to alternators and use the area where a power steering pump would be to mount it

spareparts · #3 04-21-2015, 06:47 AM

BTW, if anyone needs it, I have a brand new in the box 3.7L balancer for sale

scook · #4 04-21-2015, 11:51 PM

Spare - how long before you decide what alternators you're going to use on your buddy's boat? I really want to get mine functioning, but would wait a little to see what you come up with.

If I buy a stator on ebay and find it's shorted to ground, or other problems when I get it am I likely to get my money back - not experienced with ebay. Also, would you be inclined to go with the $50 - 100 used ones or the $300+/- new ones?

spareparts · #5 04-22-2015, 07:38 AM

ebay stators will probably not have any warranty unless it states different, even then it may be an issue as most companies won't give credit for returned electrical parts. If you go that route, look at ebasicpower, they have the stator on there for $219. Thats not much more than my cost. The 3.7s we are going to convert are a very different set up, with them being inboards, they have an unusual set up with a sea water pump and an odd engine bracket that prevents a normal conversion kit being used. We are going to have to come up with our own set up

smokeonthewater · #6 04-22-2015, 07:48 AM

On EBAY.... If the seller states that is is in good condition and you pay w PayPal then 99% of the time PayPal will refund you if it shows up "not as described". In that case you will get a shipping label to return it and when tracking shows it is returned you get a 100% refund including shipping costs.... The seller has nothing to say about it.

That said, I wouldn't waste my time installing used charging components that are just as old as the ones that failed... Once and done beats the heck out of doing it again next month.

bradford · #7 04-22-2015, 08:20 AM

Agree with Smoke, use new stuff with a warranty. Even then sometimes the new stuff doesn't work right out of the box.

scook · #8 04-26-2015, 08:41 AM

Yeah, I agree. It doesn't make sense to install something that's as old as what failed. Time to do the research on whether to go with replacing original parts or doing a conversion. Thanks

Jbreen07 · #9 07-20-2015, 05:35 PM

my voltage regulator melted a while back. very costly for a new one so I too looked into the alternator conversion, decided to go that route. there is a company that sells the entire kit, I forget the name…I bought it for I think 3 hundred and some change. installation was pretty simple, I removed all of the old charging components and have run it a good bit since with no problems! if you need more details on the process do ask.

scook · #10 07-21-2015, 12:36 AM

I bought a kit from Breezeworks. It was a long afternoon installing it - the parts all seemed fine and they fit OK. The instructions were fair - not real detailed and they told me to skip two steps (since I don't have power steering) and it should have only been one step but it was pretty obvious. Spare was right about checking that there's enough room. I had to cut about 5/8" out of the edge of the deck inside the engine well but it was all on the horizontal - didn't look like it weakened anything significantly.

Fired it up and it charged fine. I have one fishing trip on it (probably 5 miles) and no problems. It's a good project for anyone who's a little bit handy and has a few tools. I'm glad I had my Harbor Freight oscillating multi tool to make the cut in the deck, it wasn't easy to access but an old fashioned coping saw and some patience would have done it.