Voltage Regulator - YM1900

birdman8399 · Mar 12, 2002

Changes are good!! Glad we made the shift to TBN. Some of us would follow Roger_Scotty and these guys to the ends of the UNIVERSE!!! I bought my YM1900 three years ago after learning about the Yannies througth the Yahoo Club. Like many others I needed a tractor to get a home site ready (2 acres) and now I use it for cutting grass, scraping a 2000 foot driveway, gardening, dirt moving, etc.. The Yanmar was an affordable solution for a young family man with a small budget! I have learned so much as a daily reader and I am proud to be member.

Now for the technical part......

I need a VR for my YM1900. It has five spades (srew goes througth the top) and then a black wire that mounts on the side. Can anybody point me in the right direction? I have been to the local NAPA and gone througth everything that he has and no matches. I read some of the old posts in the Yahoo group and all I could find was a reference to a three-wire older Chrysler type. The altenator has four connections. Can I just by any regulator and wire it up??? What does the VR do?? Regulate voltage???? (Begging for VR education!)

vin · Mar 12, 2002

If you are unable to locate a replacement VR, I might suggest a one wire alternator to replace your generator. It has the voltage regulator built in, self excites and cuts in to charge at a low rpm. Shops get $50-$75 for them and it does away with the VR. There are a number of sites that discuss the Delco Remy 7127 (GM ) conversion, just search for "one wire alternator" or let me know and I'll dig them up.

As to the function of the voltage regulator, it certainly does "regulate" the output of the alternator for proper charging. It does this by sensing the battery voltage and permitting current to flow to the battery to charge as needed. Without it, the alternator would indescriminately charge based on RPM. A condition that could be both dangerous to the battery and the alternator.

roger_scotty · Mar 12, 2002

Birdman, it is true that with enough head scratching and meter reading and a little math that one can use just about any voltage regulator. But that's the hard way.
If you want my advice, just bite the bullet, call up Len, and order a new VR. They last a few decades, so for that lifespan why worry?
Uh...before you do, what makes you so sure it is the VR? Have you checked the battery and the alternator? What are the symptoms?

birdman8399 · Mar 13, 2002

The charging system has never worked on "Lil Red". For three years I just parked the tractor and put a small battery charger on it once a week. Well I had to put a clutch in it two weeks ago so I decided to fix the charging system. I have one of those battery checker thingys. Battery was no good. Replaced the battery and fired her up. Put the battery checker back on it and at 2000 rpm I still had 12 volts, the alt wasn't charging. Snatched the altenator off went to my local rebuilder and he said the alt was fine. He said that the alt looked like it was similar to a late 70's Datsun/nissan.

I thought about changing to a GM alt with an internal regulator but I don't want to spend that kinda funds. The clutch price wasn't bad but it still hurt! Think I'll check with Len and some of the other guys to see what kinda damge they can do (good oppurtunity to order some OEM filters!)!!!

THANKS

Soundguy · Mar 13, 2002

Hi... I'm the guy that changed to a chrysler style voltage reg.. ( and a mitsubishi alternator too ) Inew my system wasn't charging, and i took the alt and reg to the local shop, and confirmed that both were bad. The price for new scared me a bit. The alternator shop had a rebuilt mitsubishi sitting on his dusty shelf that would exactly fit the same bracket, and belt size... was for a very small car.. like a 45 amp job.. he sold it to my with a new ( old style ) chrysler regulator for 60 bucks. Bolted up fine, and worked flawlessly. You just have to identify your spade terminals of the alternator because you are going to need to know the difference between field, and the battery charging side.. usually one is a ground reference as well. Also, you will need to insure a good ground reference for your regulator as well.. or it will deffinately cause much problems. The alternator store you get your reg from should be able to draw you a very simple block wireing diagram with their eyes closed in a couple of minutes on a napkin.
If not, I and roger scotty have discussed this in depth.. and as many know... rogerscotty is the 'da man' around here.

Soundguy

allenp · Mar 13, 2002

While it may be less expensive to order a new regulator from Len or one of the other dealers that post here, I do have an Advance Auto part number of a alternator and regulator that is "suppose" to be an exact replacement. The Advance Auto number for the alternator is 14105 (Hitachi LT135-35B7IH) and the regulator is 265003. From what I understand, the connections on the alternator and the regulator are the same as the OEM parts. However, the alternator does have a slighly higher current output than the original.

Please go the Parts America Website and enter the part numbers and you can see a pic of the parts.

http://www.partsamerica.com