Glowplug circuit meltdown! Why?

[snowboy]

I turned on the glowplugs of the Mule 4010 this morning and within a few seconds smoke was coming out from the engine compartment. I turned the key off and lifted the back to find that a wire had melted it's way through the vinyl insulation and through the outer plastic sheath.

Can anyone tell me what happened to cause this?

I think I will start by pulling the three glow plugs to see if they are fried. What resistance should they test to be okay?

Has anyone else had this happen? What did you find to have caused this?

[KAWMECH]

I will bet you have a dead short in the wire some where. While driving around, sometimes sticks or other debris can pinch wires accidently

[snowboy]

Good Call

It turned out that the Relay for the glow plugs is also associated with the horn (of all things!). The horn had a dead short. When I turned the glow plugs on it burned the indicator wire for the glow plugs and ruined the relay. Oh yeah, and it blew the fuse too!

It is a good thing it was fused circuit, huh?