ford 4000 thermostart

[shawn1201]

Quick question that I have on my ford 4000 3 cyl diesel. I have rewired the tractor and I have added a thermostart to it. ( air intake manifold thermostart) . I purchased a new switch for it as the previous owner was using a screwdriver on the old switch. Looking at the ford manual and the switch, it shows the thermostart has constant power going to it even after the tractor has started. The switch does not have a momentary contact just for the thermostart and the wiring diagram shows the wiring going to the ingnition(gas tractor) or thermostart. That to me indicates that the thermostart would have constant power while the tractor was running. I was thinking that the thermostart only had power to it when using the thermostart. From everything I see that is not correct. According to the new switch which is for the ford 4000 diesel with thermostart and factory wiring diagram, it has constant power to it when the ingnition is on. Is that correct. Thanks for any help

 

[RickB]

A 5 pole diesel switch has a dedicated thermostart pole which is powered when the key is in both preheat and crank positions.

 

[shawn1201]

Yes the switch is a 5 pole/lug switch ..3 position .. so I guess the thermostart is always energized then??? No position of the switch would allow you to power the thermostart then when started the thermostart would de-entergize. At first I thought I had a bad switch went to dealer and checked out another one , ohmed it out with a meter and its the same.. I could always install a push button switch for the thermostart but if the thermostart is to allows be powered on than I leave it as though. I just wanted to make sure through before wiring it up

 

[whodat526]

there should be a five postion switch that u need for the ones with preheaters

 

[Jerry/MT]

Yes the switch is a 5 pole/lug switch ..3 position .. so I guess the thermostart is always energized then??? No position of the switch would allow you to power the thermostart then when started the thermostart would de-entergize. At first I thought I had a bad switch went to dealer and checked out another one , ohmed it out with a meter and its the same.. I could always install a push button switch for the thermostart but if the thermostart is to allows be powered on than I leave it as though. I just wanted to make sure through before wiring it up

The positions are Accesories, Off, Run, Thermostart, and Start. The Thermostart is the position between Run and Start and you have to manuallly hold it in the Thermostart position or the key returns to Run. At least that's how it is on my 4610.

 

[RickB]

Yes the switch is a 5 pole/lug switch ..3 position .. so I guess the thermostart is always energized then???

No. No. NO.

The thermostart wire (brown with red tracer) connects to switch terminal #3.

 

[HakanTh]

Perhaps US built and UK built tractor differs from one another regarding the switches. This is how it works on a UK built:

5 positions
4-3-0-1-2

0 = Neutral (You can pull out the key).
1 (first clockwise from neutral) = "Ignition" (Instrument cluster lit, gauges on, warning lamps on etc.).
2 (second clockwise from neutral) = Starter engaged, engine cranks in a normal fashion.
3 (first anti-clockwise from neutral) = Thermostart engaged, to preheat the air in manifold.
4 (second anti-clockwise from neutral) = Thermostart and starter engaged, engine cranks along with air heating.

 

[whodat526]

Perhaps US built and UK built tractor differs from one another regarding the switches. This is how it works on a UK built:

5 positions
4-3-0-1-2

0 = Neutral (You can pull out the key).
1 (first clockwise from neutral) = "Ignition" (Instrument cluster lit, gauges on, warning lamps on etc.).
2 (second clockwise from neutral) = Starter engaged, engine cranks in a normal fashion.
3 (first anti-clockwise from neutral) = Thermostart engaged, to preheat the air in manifold.
4 (second anti-clockwise from neutral) = Thermostart and starter engaged, engine cranks along with air heating.

nope not on the new switches the thermostat enganes right before the starter position and u have to hold it there just like u hold it to start there is no conter clockwise turns on it

 

[shawn1201]

Ok Guys thanks for your help. As far as wire colors with trace colors. The new wire harness I bought for the tractor none of the wire colors matched the ford manual. Also the wire harness did not included the wire for the thermostart in the wire loom. No problem I just ran another wire to the thermostart, problem solved. As far as the switch, I purchased one from the internet and that one was found to be bad after ohming it out with my meter today. Purchased a second one from the new holland dealer and ohmed it out. What I wasnt aware of is that right before the switch hits the start position to engage the starter, it has a slight resting point which is the thermostart (pole 3 on the switch). Then you can turn the switch completely to start the tractor after the thermostart is used. What through me for a loop was the bad switch to begin with. If I remember correctly from today the poles on the switch were marked 1 through 5. Believe it was as follows could be wrong though

1 -- power to switch
2 -- acc/lights
3 -- thermostart
4 -- Cant remember
5 -- starter sol.

Once again thanks for the input