JD 6120 No Glow Plug Light, No start

CassieMack · Jul 22, 2024

I have a 2004 JD 6120, went to start it and have no glow plug light and of course it will not start. I didn't force the start without the light on. I am finding nothing in the manual, nothing on YouTube on this tractor at all.

K5lwq · Jul 25, 2024

When you say no start does that mean it turns over but will not run? Or the starter is not spinning the engine?

It should run without the glow plugs energized unless it is really cold where you live.

CassieMack · Jul 25, 2024

It turns over just fine but will not start at all since the glow plug is not working. I read somewhere to turn it over for 5 seconds then let it set for 5 seconds and do that a few times and it would start without the glow plug. So I tried that, and nothing.

K5lwq · Jul 25, 2024

I suspect it is not getting fuel to the injectors. Could be the fuel stop solenoid is not getting power. Because the glow plugs are not working and it doesn’t run, it could be a ground issue for the relays or blown fuses.

Tx Jim · Jul 25, 2024

I don't see "glow plug" shown in 6120 parts catalog but I see an air intake heater & a fuel heater. Cold start aid should only be required in sub-freezing temperatures. I see cold start advance kit which changes inj pump timing during cold temperatures. Have you checked for a blown fuse? Is inj pump fuel control solenoid receiving 12 volts when ign switch is turned to on position??

rScotty · Jul 25, 2024

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K5lwq said:
I suspect it is not getting fuel to the injectors. Could be the fuel stop solenoid is not getting power. Because the glow plugs are not working and it doesn’t run, it could be a ground issue for the relays or blown fuses.

Right. The glow plug ligt not working is probably a symptom of something else not working electrically.
A diesel with normal compression in summer weather will normally will start just fine without the glow plugs being actuated at all.
I'd loosen a fuel line at one of the injectors, crank it for a few seconds, and see if you get fuel squirting out there. If not, go looking for why. It will make a bit of a mess, but is a quick diagnosis.