Ford 4600 Starter Switch

[calicopatchfarm]

Recently I purchased a 1981 Ford 4600 diesel (830 hrs) with some equipment. I have a question about the starter swith and glow plugs. It does not appear to be the original starter. After holding on glow plugs and starting, it does not appear the key returns to a run position, (seems to still be on plugs), but the dash lights go out. Do I need to manually turn the key back to a run position or is where the key sits ok? Are there two run positions?

 

[Brian Allen]

calicopatchfarm
First off, you don't have glow plugs, you have a manifold heater. This heater ignites diesel fuel right in the manifold, which preheats the intake air as it passes through the manifold.
Second, the switch should spring return to the run position.
Has the switch been replaced? Or, the starter? Or, both?
Does that help?
Brian

 

[calicopatchfarm]

Brian,

It seems the starter swithch was replaced. When you turn the key from the off postition, you go to a run postition?, turn to the right again the dash warning lights display, turn again to start. The spring returns the key to the position where the lights were on. The warning lights turn off since the tractor is running. Should we leave the key in this postition or move the key one to the left? There would still be the off postition one more to the left. There seems to be two run postions for the key.
Thanks for your help.

 

[Sean in PA]

I may be wrong, but I thought that the proper switch for those diesels had the preheat position to the left side of off, and everything to the right of off was the same as the switch for a gasoline model?

 

[Keith Williams]

Calioco Patch Farm,
If you have a test light, or better still, a test meter, you need to check for voltage at the start assist. The assist is in the intake manifold. The assist will have a tube coming into it from the fuel tank and a wire from the switch. Check the wire for voltage at each position.
The way you have described this switch, it sounds like the first position turns on the start assist and the second is the run. BUT THAT IS JUST A GUESS!
Keith

 

[Brian Allen]

calicopatchfarm
I own a 79 4600, my heater does not work either, I just plug the block heater in.
Your switch if original, should have power to the heater in the manifold, when you hold the key against the spring almost in the start position.
If it starts to turn over you have gone too far.
You can verify where it provides power with a tester, or light as another poster mentioned.
Once you find the correct position, trouble shoot from there, if it does not work.
Post back.
Brian

 

[Kirk Grau]

As Sean mentions manual says switch counter-clockwise (left) for "Thermostart", but the switch on my 3600 works only toward the right as well. An old Ford guy told me just put the range lever in gear and turn the key all the way over to start. It will energize the heater, but won"t start due to the neutral lock out. Count to 20 or 30 and place lever in neutral to start. A year or two ago I was having some starting issues so spent quite a bit of time with meter and the back side of my switch. Can confirm that that is how it works. Saves having to find that "sweet" spot between run and start which can be tough with gloved hands in the cold when you really need it.

HTH,

Kirk

 

[calicopatchfarm]

Thanks to everyone for your replies and thoughts. I guess my main question is what position to leave the key in after the tractor is started. I do not have any trouble starting the tractor. There is three postions the key can be in after it is released from the far right start position. The far left is off but there is two positions between the off and start. This does not appear to be the switch described in the owners manual so I am assuming it has been repleased. My fear is that one of the two runs positions will not charge the battery. Any thoughts or similar switches?

 

[Brian Allen]

calicopatchfarm
Does your generator light glow, when it is not running in either of the two positions?
If so, it should charge in that position. Test with a meter to verify, should be running + or - 14 volts.
Brian

 

[Kirk Grau]

Should spring return to run position.

In the archives here you can find discussions of my issues with fuel in the crankcase. Replaced Thermostart as well as rebuilding injector pump. I think both were needed since they helped the issue, but i was still leaking some fuel into the oil. Ended up replacing the switch while troubleshooting some other issues and noting that the key did not actually return all the way to run, leaving the thermostart energized. No longer have fuel in the crankcase.

Long story short try to get key back to "run". Except for energizing lights and charging system, you could just return the key to off.

Kirk