1963 Ford 4000 SOS Wiring Diagram

[nashranch]

Somebody has had their way with the wiring on this newly purchased Ford 4000 SOS Diesel. I can hot wire the lead to the starter and make it turn over and start. There is a wire going into the top of the SOS cover that is grounded when it's in Park. Not sure that right. The manifold heater relay clicks and supplies power to the heaters but the switch under the other side does nothing to fire the starter relay.. I just need a correct wiring diagram to go by so i can troubleshoot this.

Thanks in advance

 

[Sean in PA]

There is a wire going into the top of the SOS cover that is grounded when it's in Park. Not sure that right.

That is correct for the original wiring on that tractor. The push button for on the right side of the dash should complete the circuit from the non-hot side of the solenoid primary to the wire going into the transmission top cover that goes to the Park safety start switch. So the Transmission needs to be in Park and the button needs to be pushed in order to complete the circuit to ground for the starter solenoid. The other side of the solenoid is always hot when the key is on. At least that is how it was when it left the factory. I cannot attest to what changes might have been made to that individual tractor over the years.

 

[nashranch]

Turns out the new solenoid I put in for the system was either no good or it was wired differently from what I need. I swapped relays with the heater relay and know the tractor starts properly.

Do they make relays that are wired different?

 

[Sean in PA]

Yes, most modern automotive solenoids have the primary grounded to the case because they work by applying voltage to the primary and the case completes the circuit to ground. Those old Ford tractors need an isolated primary that is not grounded to the case because it works by using the starter button to completes the circuit to ground.

 

[nashranch]

I'd still like to see a wiring diagram of this 1963 Ford 4000 with a SOS

 

[Sean in PA]

(quoted from post at 10:36:22 08/10/23) I'd still like to see a wiring diagram of this 1963 Ford 4000 with a SOS

The starter circuit is the same as any of the 1956-1964 tractors, except that instead of a single neutral safety start switch button down on the top of the trans, it splits the functionality into two parts, the Park safety switch inside the transmission, and the pushbutton on the right side of the dash.

 

[Hbaxter]

(quoted from post at 07:36:22 08/10/23) I'd still like to see a wiring diagram of this 1963 Ford 4000 with a SOS

I am having the same issue with knowing where the saftey starter switch is routed! I have several service manuals including the big factory parts and service manuals which are not very helpful I have a single wire coming from the switch through the cover that has been disconnected. Where is it connected/ what circuit is it in? Is there supposed to be two wires coming from the cover etc. is it a grounding switch? Unfortunately the wiring on my tractor is completely bastardized with most of the wiring all red and I trying to sort the whole mess out. This is an elementary wiring system I trying to restore with logic of the time.
Thanks for any insight there might be rather than the obvious statements it s dangerous if unfunctional .

 

[nashranch]

PM me HBaxter ...i can give my phone number so you can call me if you want. My 63 4000 SOS is all sorted out and works great. Maybe i can help you sort yours out