I replaced my fuel shutoff solenoid today. I replaced the rubber washers that go around the screw to protect it from contacting the housing. I also replaced the washers on the outside with a new set of neoprene washers. As a precheck i connected the back wire on permanently. I then turned on the ignition key and tapped the front wire to the power connector to make sure the solenoid could move. I heard a click from the solenoid but immediately after I saw a small amount of smoke coming from the part in the picture below. The yellow wire at the arrow was warm to the touch. What could I have done wrong and what part is it that lost a little of its smoke and any suggestions what to do next. The wires were disconnected when I got it so my only thought is I might have wired those two pins backwards.

 

That's your glow plugs controller. The smoke means you have a bad connection back there. The glow plugs consume about 120 amps for about 20 seconds, so there's a lot of current going through that system. You should look at the connections and make sure they're clean and tight.

 

Thank you for that info. I found a diagram and i may have plugged my fuel shutoff solenoid into the cold advance solenoid. Im gonna try to switch them in the morning see if that makes a difference. This was never a problem until I replaced the fss

 

Connecting the FSS to the cold advanced solenoid wire won't cause smoke or any immediate problem. It'll cause your truck to die when it gets warm.

 

As mentioned, thats for the glow plugs if the yellow wire is a large one, it likely is the battery feed, and may get warm with the aforementioned 120 amps the glow plugs are pulling. That would be somewhat normal and not a real concern, the engineers used as small a wire as possible to save pennies wherever they could (also a reason the voltmeter on these trucks tends to drop when the headlights and heater fan is blasting pulling the cluster voltage down, while the actual battery voltage is still fine). May just be some dust or bugs/mice stuffed something in there, but definitely needs to be checked out. There is a good sticky on the top of the forum discussing the glow plug system.

Chances are, its a complete fluke that it happened when you were under the hood watching.