641D starter switch

[questadg]

I would like to restore the tractor to original starting system. It appears that someone rigged a solenoid from another vehicle and wired it to an aftermarket push button switch. I have the original solenoid and want to purchase the original style switch. The tractor is currently 12 volt. I am also going to order the service manual. So, does the IT service manual have a wiring diagram that will be helpful? I want to wire it up correctly.

 

[souNdguy]

there is a diagram in the fo4.. and plenty online.

luckilly these old machiens have pretty easy wireing.

still got the solenoids for the thermal start aid?

 

[john in la]

Do you need a complete wiring diagram or just the starter wiring??
The manual will have a complete diagram for the original 12 volt generator. I do not know if the IT has starting aid (glow plugs) diagram though if you have them.

For the starter your solenoid will have 4 post. 2 large and 2 small post.
Hook + battery to right large post.
Hook starter to left large post.
Run a wire from key switch or terminal block (side that is hot only when key is on) to the right small post.
Run a wire from starter button on trans to left small post.

How it works...........
You turn the key on to provide power to the solenoid small post.
You push the starter button providing a ground path for said power.
The flow of electricity threw the solenoid (small wires) creates a magnetic field connecting the 2 large wires allowing battery power to flow to starter.

 

[questadg]

There is another solenoid mounted further up in the dash. That appears to run to the two plugs mounted in the intake manifold. The plugs are not hooked up and present owner says he has never used them. Tractor starts right up without them. I would like to have those working also.

 

[souNdguy]

i agree.. deffinately get them working.