# Ford 4000 thermostart (coldstart)



## oldmanfarmer (Mar 24, 2016)

Hello all again,

This might be a little premature but a need to know that i am on the correct path.

Ford 4000 3cyl diesel has a cold start feature that ford calls a thermastart. It has been disconnected and the wire from the injector heater is missing. The wire that connects to the injector heater to a disconnect is missing but the wire connects to a brown wire with a red strips goes to the key switch.

I was testing the wire to ground so i could make sure it was the correct wire but it seems to have voltage to it at all times.

When you turn the key one notch counter clock ways it is suppose to turn on the therostart heater.

When you turn the key two notches, it turns on the heater and tries to start the tractor. Correct?

Well I noticed voltage is continuous even if off, and when you turn the key two notches counter clock ways some time it will try to start some times it will not try to start.

I cant find out what voltage is supposed to be at that wire?
And what may be causing it to be intermittent at starting?

I will probably have to take the dash and key switch apart but waiting for a warmer day and all my information first. if any one has any diagrams besides this one it would be appreciated.


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## sixbales (May 18, 2011)

Howdy oldmanfarmer, 

Welcome back. It's been a while since you last posted. I trust that your Ford 4000 is performing OK?

I found the attached on the YT forum, written by Greg Wolodkin, should be helpful. The diagrams with the post did not copy. I'll try to get them and re-post:
______________________________________________________________

"OK, from my manual an original tractor would have had a 5-position switch with these positions: / heat start / heat / off / run / start / where off was center, clockwise to start normally, counter-clockwise to start with heat. Manual says to move the key switch back to the run position after heat start. 

Mine had been replaced with an aftermarket 3-position switch, which I replaced with a four-position switch: / off / run / hold-for-heat / start / which is spring-loaded to return automatically to the run position. 

The wire for the thermostart should be brown with a red stripe, from pin 3 on the key switch to the heater on the front of the intake manifold. 

For any aftermarket switch I'd test it with an ohmmeter to be sure that your power from the battery/regulator comes into the switch, and goes nowhere with the key off (also chains power over to the light switch). In the run position, power to any accessories. In the heat position, power to the thermostart. And in the start position, power to the solenoid. 

To start in cold temps, set throttle to half open. (If you have the Simms inline pump, set throttle to wide open, push excess fuel button in, and return throttle to half open). Turn key to heat position and hold for 30 seconds. I usually hear a muffled pop after about 25 seconds, sometimes see a wisp of smoke. I assume that's normal. Then crank it over. 

The schematic I have is almost useless because the greyscale or colors didn't copy into the reprint manual. You can see that in the third image.. you'll have to imagine the connection from pin 1 to the regulator, from pin 2 to accessories, and form pin 3 to the solenoid."


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## oldmanfarmer (Mar 24, 2016)

Thanks.

The information is great. 

I cant find what the voltage should be anywhere. 

Any suggestions as to why it intermittently starts/no start from the heat/start position? 

Besides the switch being bad? 

I was told it was a new 5 position switch and it dose act like one and the wires are hooked up to it correctly. 

But the brown wire with red stripe is not connected to anything on the heater side and always has 12 volts. 

As I understand it the voltage should only be there when the key is in the heat mode or the heat/start mode.

Yea I know another strange thing, it happens to me a lot. I don't know why I get the odd ball problems.

I guess I will have to rip it apart and re work it?


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## BigT (Sep 15, 2014)

Hello oldmanfarmer,

The voltage to the thermostart is 12V. If you put the keyswitch in the "heat" position, and using your multimeter, you should find 12V on one terminal of the switch. When you turn the keyswitch to the "off" position there should be no power to that terminal. If it checks out OK, that is where the brown wire with red stripes goes. Otherwise, the switch is wired wrong, OR you have a defective switch. 

Regarding the intermittent cranking in the "heat/start" position, do you have the same problem when you turn the key CW to the "cold start" position? It may be a problem with your transmission safety switch. Very common. Try jiggling the hi/lo shift lever while holding the key in the crank position. Or bypass the transmission safety switch.


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## JGPenfield (Mar 10, 2016)

I have a 3000 diesel and had to rewire everything because wires don't last 50 years. It is easy to replace the heater. It just screws in and out. Voltage is 12 volts. Mine had a push button with a spring so you had to hold it in to heat. I replaced it with a second keyed ignition switch so I had to hold it like I was starting it and it would turn off when not heating. Positive is the wire going to it. Negative is just being screwed into metal. You could just take a hot wire from the battery and touch it to the terminal on the heater in a pinch before you get it wired properly. 
For bad starts it could be the wire to your ignition switch, the ignition switch, the wire from the switch to the starter, the starter solenoid, the positive wire to the battery or the starter itself.


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## oldmanfarmer (Mar 24, 2016)

Thanks guys great help. 

The guy a bought it from bypassed the neutral safety switch. I found that out the bad way, luckily no one was in front of it and for once I am glad it did NOT start.

On the switch I was not sure that when you turn the key to heat/start that the heater did not have to get to a certain temperature before it would turn over. I guess not. I am still learning this tractor. After a few years with this thing I should almost be dangerous in knowledge. Ha ha. 

Thanks for your help. I will let you all know how it goes.:tractorsm:tractorsm


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## ford64011 (Jan 4, 2019)

oldmanfarmer said:


> Thanks.
> 
> The information is great.
> 
> ...


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## ford64011 (Jan 4, 2019)

I have a ford 4000 3cyl that does not have glow plugs. installed new wiring harness that came with a thermostat wire. tractor will not start or turn over. wondering if I have to do something to this wire to start tractor. thanks.


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## thepumpguysc (Jan 25, 2015)

No sir.. THAT WIRE is for a "thermo-start" its a starting AID.. & has nothing to do w/ the starter motor turning..
Its time to recheck ALL your connections & MAKE SURE your levers are in the NEUTRAL positions.. Good luck


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## ford64011 (Jan 4, 2019)

thanks. found that pto lever was in the engaged position. placed in neutral and tractor started right up. never worked on tractor with this type of switch before so my bad. thanks for the help.


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## Hacke (Feb 22, 2011)

Normally it is the hi/lo gear shifter (Park (P) on Select-O-Speed gearbox) that acts upon the safety switch.


User Manual:
https://www.tractorforum.com/manuals/ford-2000-3000-4000-5000-operators-service-manual.2/
and
www.ntractorclub.com/manuals/tractors/Operators%20Manual%20All%20Purpose%20and%20LCG%20Tractors%202000,3000,4000,and%205000.pdf

Tractor identification:
https://www.tractorforum.com/manuals/ford-1000-series-identification.11/

Shop Manual:
https://www.tractorforum.com/manuals/ford-2000-3000-4000-3-cyl-1-65-12-74-shop-manual.6/

Wiring info:
https://www.tractorforum.com/manuals/ford-1000-series-1-65-12-74-wiring-info.13/


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