Help! Farmall 400 12v Conversion

TylerFarmallH · Aug 27, 2012

Hey guys, these are some pictures and an attached youtube link of my neighbors 400 conversion I am having some problems. I have done this one before succesfully on an H but this one is giving me fits.

The Alternator Hot wire is going to the amp Gauge
The other line going to amp guage is from the positive side of the coil.

I think the problem comes in for me with the starter, it has a seperate line for the solenoid, but that also how it was wired for 6 volt and it worked fine... Any help is appreciated!

Everything checks out fine as far as what is hot and what isnt compared to my succesful H conversion. but the switch on the 400 doesnt have a hot wire running to it. However the switch worked fine as a 6 volt. We literally changed nothing in the dash panel. I hope you can look at the video link I posted too. Just copy and paste it into Youtube.

http://www.youtube.com/watch?v=FEosUVGBZn4&feature=youtube_gdata_player

oldtanker · Aug 27, 2012

OK take a look at this.

The wire you have running to the hot side of the coil can be there but there has to be a wire from the ignition switch to that post too. That wire is the exciter wire that when energized tells the alt to charge. It has the diode inline to prevent it from back feeding electricty and draining the battery when the engine is off. Without the diode it will backfeed enough that it willl feed the ingition system too not allowing it to shut off.

The wire on the other side of the amp meter has to feed back to the battery to charge it.

howdy1960 · Aug 28, 2012

Oldtanker, I understand reason for diode but what's reason for 'spare'? I presume in case 1st one fails. Would it be consired overkill to install 2nd in parallal (sp) with 1st?

Janicholson · Aug 28, 2012

They often come in a package of 2 or 5 Jim

oldtanker · Aug 28, 2012

(quoted from post at 09:23:02 08/28/12) Oldtanker, I understand reason for diode but what's reason for 'spare'? I presume in case 1st one fails. Would it be consired overkill to install 2nd in parallal (sp) with 1st?

I honestly don't know. That was a picture that a guy sent me and told I could use when I did my first conversion. I've now done over a dozen. There is an auto electric shop here that sells the plug pre wired with the diode and nicely shrink wrapped, I buy those. I've never had to replace a diode on one.

Rick

mkirsch · Aug 28, 2012

One terminal from the ammeter should go to the + post of the battery, or the battery connection on the starter solenoid.

The other terminal from the ammeter should connect to three things:

1. Hot to the headlight switch
2. Hot to the key switch
3. Hot to the BAT terminal on the alternator

The 400 has a twist-key-to-start setup so the key switch will have two other posts:

A. Hot to the ballast resistor
B. Start to the "S" post on the solenoid

The ballast resistor will have two connections:

I. Key switch side to diode and on to the alternator's #1 terminal
II. Open side to + post on coil, - side of coil to distributor

If it's hooked up that way and still doesn't work, check your work again because it isn't hooked up that way. Either that, or you have gremlins.

oldtanker · Aug 29, 2012

Tyler, did you get it fixed?

Rick

TylerFarmallH · Sep 9, 2012

(quoted from post at 04:12:28 08/29/12) Tyler, did you get it fixed?

Rick

Yes, it was the strangest thing. There was a black wire not in the diagram that was more than just a ground. Im not sure what the remedy was but it got fixed. Very strange...

Help! Farmall 400 12v Conversion

TylerFarmallH

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oldtanker

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howdy1960

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Janicholson

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oldtanker

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mkirsch

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oldtanker

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TylerFarmallH

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