Alternator replacement

[MooseDriver78]

Stock alternator on Universal M35B wasn't charging batteries, after troubleshooting I found the positive stud on the alternator corroded. When I went to clean it up, the stud fell off in my hands! I pulled the alternator and found it in pretty rough shape, glad I caught this.  After hours spent reading this forum and marinehowto.com I've purchased a new Balmer with external regulation. Hopefully the install goes well as we have a trip planed to Angel Island in SF Bay this coming weekend.

I think 100A alternator is overkill for my current battery set up (2x 135ah house bank), but I will be upgrading to LiFePo4 in the near future.

I just wanted to say this forum and marinehowto is such a great resource, especially for someone who is fairly new to sailing and boat maintenance. Thank you everyone for all the wisdom here! 

[Stu Jackson]

Good move.  Hope you saw this one:
Alternator Regulator Wiring Diagrams - all three http://c34.org/bbs/index.php/topic,4548.0.html

Hope it helps, good luck.

[MooseDriver78]

I did see that, but the only available regulator I could get in time was the ARS-5 which doesn't have a dedicated volt sense. My plan is to leave the alternator wired to the C post of my battery 1/2/B switch just for the near term until I can get in there and re-wire it directly to the battery bank and update my battery switch. Do you see any issues short term in doing this? As long as I don't blow up my batteries, I'm ok with a poor charging profile until I get my system updated.

I have 2x 135ah house batteries, no starter battery. That's a future upgrade.

[Stu Jackson]

Then I guess you saw this one, too:
Alternator Regulators - The Differences between ARS-5 and MC-614 Units (scroll UP to see reply #5)
http://forums.catalina.sailboatowners.com/showthread.php?p=1103132


As far as wiring your AO before you go to the house bank, you have two options:
1.  As you said to the C post
2.  To the house bank post on the switch

The advantage of #2 is that it IS essentially wiring it to your house bank, because it's just the other end of the same wire!  The other advantage is that you don't have to remember to switch the battery switch once you stop motoring.  This assumes your "other" bank is a reserve bank and you start your engine with the house bank.  In any event, your "start" battery rarely needs more charge because you have a ton of starts available in it even without recharging.

[MooseDriver78]

I have 2 identical house batteries wired as battery 1 and battery 2. No starter/reserve battery as is. Adding a starter/reserve battery was going to be my next project until this alternator raised its hand and got to the front of the line .

Immediate goal is to just get running for our planned cruise out this weekend. Then when I get back I'll have time to fine tune it all.

[Ron Hill]

Moose : You can dumb down your alternator output with the settings on your external Voltage regulator!!

I set my 120amp alternator at 75 amps!! 

A thought

[MooseDriver78]

Moose : You can dumb down your alternator output with the settings on your external Voltage regulator!!

I set my 120amp alternator at 75 amps!! 

A thought

Thats the plan, how did you end up at 75 amps? I'm thinking of starting out at 50 amps to be really conservative until I get the system re-wired and possibly adding the small engine mode switch I've been reading about.

[Ron Hill]

Moose : I had my alternator rebuilt. The rebuilder had two stators one @ 80 amps and one @ 120 amps.
Bigger is better- Right!! I almost passed out when he told me I now had a 120 amp alternator!!
It was time for a new Balmar Voltage regulator - so things worked out anyway. The original rating was 75 amps, so that's what I dumbed it back down to. 

A thought

[MooseDriver78]

Well, I got the Balmar 621 alternator with ARS external regulator installed. I did the basic programming with the regulator, will go back in and nerd out with it later. It was a very tight fit, the stock alternator adjustment arm just barely gets the belt tension to specs. During the install, the oil switch positive wire prong broke off...it must have been bent back and forth in its past as it just fell off. I made the mistake of just trying to wrench off the oil switch and broke off the brass elbow. Luckily my local auto parts store had an elbow and replacement oil switch in stock! Quick work with an easy out and the new elbow and oil switch installed. What a project! I finished late the night before our cruise out to Angel Island so it all worked out. We had a wonderful long weekend sailing around SF Bay, went out the Golden Gate for the first time, saw 30 knots apparent wind and sadly saw somebody shred their spinnaker.

[KWKloeber]

During the install, the oil switch positive wire prong broke off...it must have been bent back and forth in its past as it just fell off.

Luckily my local auto parts store had an elbow and replacement oil switch in stock!

Quick work with an easy out and the new elbow and oil switch installed.

@Moose

I have posted this about a zillion times before. 

The oil pressure switch terminal breaks off because of the STIFF AUTO WIRE that Westerbele uses on a MARINE ENGINE HARNESS instead of flexible MARINE WIRE.

The vibration and movement of the harness wire transfers to the switch terminal and eventually it work hardens and breaks. 

ZIP TIE DOWN the harness so that there is no movement possibly transferred to the switch terminals. 

DO yuo have the aftermarket part number of the replacement switch?  Is it the same length or a "long" form factor?

Isn't the brass tee brazed to the engine bracket?  Or wasn't that "injured" during the mishap?

[MooseDriver78]

@KWKloeber, that makes sense and I did zip tie up all the wires so they are nice secure but thank your for your zillion previous posts!   

I don't have the part number of the replacement switch with me, I left the box it came in on Honu, but it is the exact dimensions as the broken one that came off the engine. More importantly it is rated at the appropriate PSI per the manual.

The brass T is brazed to the bracket, I broke the elbow off that the switch screws into. I was able to use an easy out to extract the broken elbow and just put a new elbow on for the switch then screw the bracket back onto the engine.   

[KWKloeber]

@KWKloeber, that makes sense and I did zip-tie up all the wires so they are nice secure but thank your for your zillion previous posts!   

I don't have the part number of the replacement switch with me, I left the box it came in on Honu, but it is the exact dimensions as the broken one that came off the engine. More importantly, it is rated at the appropriate PSI per the manual.

The brass T is brazed to the bracket, I broke the elbow off that the switch screws into. I was able to use an easy out to extract the broken elbow and just put a new elbow on for the switch then screw the bracket back onto the engine. 

This Autozone switch cap prevents damage to the switch terminals!

https://www.autozone.com/electrical-and-lighting/oil-pressure-switch-connector/p/duralast-electrical-wire-connector-1053/518356_0_0