Fixing my alternator part 3 - should I bother?
 

Fixing my alternator part 3 - should I bother?

Started by neoneddy, September 18, 2018, 09:59:24 PM

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neoneddy

I've had a few posts on here, a quick recap. Suddenly noticed a lack of charge current from coach to house batteries, checked voltage (low) checked regulator (works fine) tested alternator under full field unregulated mode, no change.   

I opened the back and found 2 maybe 3 bad diodes. Replaced those, no change. I still get some current but not  what I should. I'm suspecting I have some shorted stator windings .

My escape option is $1300-$1500 to get a new one installed.  I'll do it , but I also like to DIY this stuff. I also know these things are heavy. I figure if I work anymore on the 50dn I should remove it. On the MCI it's burrows behind the engine. I have been working on it from the driver's side access hatch by removing the air cleaner vs the top access hatch.

Anyone removed these ? Is it worth the Hassel? A new winding is $300-400 alone, plus my time is worth something I guess.

I've got an outing planned in a month and would like full charging capacity again.
Raising hell in Elk River, MN

1982 MCI MC9

6V92 / 4 Speed Auto (HT740) Video Build Log - Bus Conversion & RV Solar company we now started thanks to our Bus

bevans6

Easy check is stator resistance, 24v 50DN stator resistance is 3 - 3.4 ohms.  http://shop.pwt.ca/DRT/Vendors%20Manuals/09600%20Generator%20-%20Delco%20Remy/Delco%20Remy%20TS-50DN-T%20technical%20bulletin.pdf

There are two field terminals, F1 and F2.  F2 is usually strapped to the frame for ground.  I would disconnect the strap and measure resistance between F1 and F2, should be 3 - 3.4 ohms, and between F1 and F2 and the frame, to check for a grounded coil.
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

buswarrior

Be sure to take note of the electric junction box just inside that access door, and figure out how to protect the connections/cables when you thunder that alternator out of there.

Ramming one of those connectors will make you a lot more electrical work...

A collection of lumber to make a ramp is how I did it. coming out is downhill, not so bad, a controlled descent...

An auto trolly jack came in handy for some of the install lifting, again, lumber bits to get the elevations required. Used it to get my barely balanced lumber ramp up higher so I could push it up the hill. Everything is about avoiding lifting it, get it propped, rolled, hoisted, pushed, MacGyver'd yup into there. A straight lift is for young guys with women watching...

It is ok to take a rest, get it in there somewhere and leave it. Come back later, or tomorrow, or 2 days from now... whatever recovery time is required.

Males have a real hard problem taking a break in the middle of a job. If your grip and fore arms are done for the day, you are going to break something, or yourself.

Whether it is worth it, depends on your charging strategies, and how you use the coach. Some busnuts, the engine alternator does the majority of house bank charging as they change locations frequently, and avoid the power pole. Other busnuts use other methods to do most of their charging, generator, solar, plugged in somewhere.

Your design, your camping style, your choice.

My preference in a build is to keep the stock coach heating, so the big alternator is half way justified already. Replacing the stock regulator with a 3/4 stage one does a slick job of charging the house bank properly.

Good luck with the decision, hard to do looking forward, easier to do looking back.

happy coaching!
buswarrior
Frozen North, Greater Toronto Area
new project: 1995 MCI 102D3, Cat 3176b, Eaton Autoshift

neoneddy

Out of the blue update here.  I have scrapped along with solar on my fall trips here with no issues. I figured I'd get the alternator swapped in the spring or late fall.

I ran the bus today for another project, I took a look at my voltage and watts in and noticed 30+v and over 500 watts in! So I went and adjusted the voltage down to 28 or so.

I wasn't sure if what I was seeing was right, so I turned on a 1500 watt space heater and sure enough it showed 28v still and 1500 watts coming from the coach side. Last time the voltage dipped to 26 or so, showing hardly any help from the coach side.

Attached are screenshots from my monitor system, you'll notice when I had a larger load on it , the voltage never dipped!

So, I'm trying to figure out what happened, could there have been a short in the windings and then it shorted again someplace to create a working unit again? I guess I'm cautiously optimistic.

So I took it out and ran it, running the heater blower etc, it all worked great.
Raising hell in Elk River, MN

1982 MCI MC9

6V92 / 4 Speed Auto (HT740) Video Build Log - Bus Conversion & RV Solar company we now started thanks to our Bus