Anyone know what that little critter is? It sits about dead center on the passenger side fender well, and when I turn my key I can hear it run- sounds like a small pump of sorts. I forgot to snap a pic, I'll try and get one tonight if it will help.

 

That's the solenoid relay for your starter. If you unplug that little snap on wire on the small post your truck won't start. It's an easy way to disable the truck in a pinch.

 

Mine decided to go, and not work, but it never made noise. just didn't work when it got warm.

you can jumper the big post if your truck wont start. I had to, but didnt' like doing it.

 

First thought was girlfriend/wife but then that's not on the fenderwell, just pass. side. Isn't there a vaccum pump over there as well?

 

I believe you will find that is the vacuum pump.

 

Vacuum pump makes more sense for what I'm talking about than the starter solenoid. Is it supposed to make all that noise?

 

Yep -- normal. Diesels don't have a vacuum like gassers, so to run the climate control stuff (and SoTF 4WD if you have it), we need an electric vacuum pump.

 

Okay, good to know. Learn more about this truck every day on here!