MF 50 Alternator Conversion

ElkoMF50

New User
I have a MF 50 and converted it to an alternator. Mounting was easy but wiring is tough especially for me. I researched the heck out of it and figured I knew what to do. I got a SI1(single wire) and ran the wires. On the alternator I connected the #2 flat terminal to the batt stud. I ran the #1 flat terminal to the hot start on my ignition. I know every drawing I saw ran it to the oil pressure gauge but I have an a mechanical gauge. The batt wire from the alternator goes directly to the positive post on my amp gauge and the wire from the negative stud goes directly to the stud on the starter. I checked all connections and they are tight and it cranked up almost instantly but not getting and charge from the alternator. My amp gauge read basically zero and output from the batt stud on the alternator reads whatever the battery is charged too. When I checked it while it was running my meter showed 12.3 volts. I know this probably easy for most but I never saw one post to remove the external vreg but I figured since the alternator has a build in regulator I didn't need the external unit. Other than taking the alternator off and going to the parts store to check it I'm at a lost. I know you can get parts new from the store and they can be bad, also my lovely wife was standing there when I first cranked it up and she said she saw sparks coming from the front of the tractor and then they quit. I just figured the new belt had a wire sticking out form where it was made and the pulleys rubbed it off. Any suggestions would be helpful as electrical is defiantly not my strong point.

Thanks Derrick
 
Assuming you mean a 10SI single wire alternator... Your post is a bit confusing. You mention other wires other than bat wire. Sure you don't mean you have the 3 wire variety? If it truely is a single wire job you have to rev it up to like 2k rpm's for the exciter to activate and start charging. A quirk with the single wire units. You can put a smaller pulley on it to lower the rpm kick in range or get a low rpm regulator and it wont matter.
 
Also... Belts haven't had wires in them for decades. They are all a composite of rubber and webbing or cording. If there was sparks flying around something bad happened.
 
You can also get a low cut in regulator for the 1 wire alternator. I've done the conversion to several of mine and they start charging right away, no need to rev up. You can get just the regulator or a complete rebuild kit for less than $20 from:

https://www.aspwholesale.com/voltage-regulator-dr-p1627.html
 
Sorry for the confusion. It was a long day.
You are correct it's a 10SI or at least that
was what I ordered. What I received was an
alternator that has a stud labeled batt and
place that has two terminal spades. I read
several online post saying to hook up these
two wires and some just ignored them. I
liked the idea of having the alternator
charging without review up a cold engine. If
I get a low cut in regulator for a 1 wire
alternator where do I run the wire too? The
stud on the starter solenoid?
 
When you got the alternator did the two spade plug section have a rubber plug installed already or was it open. The 10SI has both 1 and 3 wire options. If yours came with the plug installed that means it was converted to be just a single wire only and you leave the plug in. If it came with that plug open and ready to accept the pig tail then it's a 3 wire variety and needs to be hooked up as such.
 
It came with the plug. So what direction do
I take? Does it mean that I need an external
vregulator and where do I run the single
wire to?
 
Here is a ONE wire 12 Volt Alternator Negative ground:

Purchased from YT Tractor Site:

One and only one wire is ran to one side of Amp meter:

Other connector on Amp meter is ran to and connected to Positive supply from BATTERY at Starter:


Anything above 725 Engine RPM Alternator operates PERFECTLY:

MF FE-35 X
a155083.jpg

a155084.jpg

a155086.jpg
 
Ok so if it came with a plug then it was converted to a truely one wire setup like john deere d is showing. If you pulled the plug and tried to hook up the wires there then the sparks you saw was the regulator exploding.
 
Make sure you check the amperage rating for that alt. If you went for the cheaper model like I did it most likely was a 60 amp model, not the 30 amp. (The new regulator was more expensive than a new alt). Unless you install a different or additional shunt you will have to change the ammeter. I changed the ammeter.
 

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