# ford 4000 diesel wiring issue



## ford64011 (Jan 4, 2019)

just installed new wiring harness on my ford 4000 3cyl diesel. (1973) used sparex wiring harness. now it will not start. only wire that I was unsure of was a wire for the thermostat. was told by seller it was not needed. turn key all dash lights come on. good battery. head lights work. jumped gear box safety switch. no change. any help would be great. all other parts are new. thanks.


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## RC Wells (Dec 26, 2008)

I presume you are working from this first set of instructions below:

But you also need this second harness: 




*Safety Start Harness *
*S.67186 *


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## Ultradog (Feb 27, 2005)

ford64011 said:


> just installed new wiring harness on my ford 4000 3cyl diesel. (1973) used sparex wiring harness. now it will not start. only wire that I was unsure of was a wire for the thermostat. was told by seller it was not needed. turn key all dash lights come on. good battery. head lights work. jumped gear box safety switch. no change. any help would be great. all other parts are new. thanks.


I would take a VOM or test light and check for voltage at terminal 7 when you turn the key. How did you bypass your neutral safety switch?
You can take the two wires from under the dash and temporarily plug them together to test.
If still no power to #7 recheck your start connection on the keyswitch.
By the way, the diagram is incorrect in that they say terminal #6 is for the thermostat. It is not for the thermostat. It is for the Thermo Start - a cold weather starting aid.


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## Hacke (Feb 22, 2011)

Just a thought:

If your ignition switch works like the one in the attached picture, could it be that the old one had the starter wire on lug #3 at the ignition switch, and you are used to run the starter at position 4 in the picture?

You need to go a notch pass position 4 to position 5 in order to run the starter. Both 4 and 5 have spring returns.


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## Hightech1953 (Dec 30, 2018)

Mine did the same thing when i installed new harness and key switch. My starter solenoid had hung up somehow and had to tap the starter with a hammer . Everything was good after that.


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## Hacke (Feb 22, 2011)

*ford64011*/

According to your postings in this thread:
https://www.tractorforum.com/threads/ford-4000-thermostart-coldstart.33087/
your problem is solved. Right?


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## ford64011 (Jan 4, 2019)

found the problem. my pto shift lever was in the engaged position. moved it and tractor started right up. thanks for all the great info.


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