Glow plugs and harness............
That is a bad design of a harness if I ever saw one! Wow. Truck didnt want to start this morning. Temps close to 15*, wind chill near 0*. Truck was not so hard to start in the cold before I did my studs. So I had to sit back and think about what I did to cause the cold start issue.
My block heater was plugged in. It will stumble when cranking, and spew a little black smoke. Got fuel. Hmmmm. I left the glow plugs in during the entire stud process. Making sure to have blocks of wood to set the heads on when setting them down.
Thinking about how glow plugs work- center pin that wire harness plugs onto is fed 12V+. The housing, which threads into the block, is your 12V-. If I had set the heads down (all 120+lbs), and set them down on a glow plug, I could have bent the business end of a plug. Which when looked at on a bench test, allows very little clearance between the center heating pin, and the threaded housing (which extends downward with a sleeve).
I picked up 8 glow plugs from Napa. And decided to change the driver side out before it got dark. Back three plugs, piece of cake. The forward most plug was a b!tch!. The harness was frozen into the head. Trying to pull it out by the wire only resulted in ripping the wiring in half. Grabbing it with pliers- yeah right. The housing just broke off in pieces. I drilled a hole into the plastic, and put a #14 stainless tapping screw into it, and yanked it out with pliers. The plastic housing of the harness was caked with aluminum corrosion where is meets the head. Sweet. Saturday afternoon, Ford parts are closed till monday.
I installed the four plugs, cleaned the heads off where the harness plugs in. And now I wait until monday when the parts dept is open.
I bench tested the plugs I pulled out in the garage. 3 out of 4 tested NG. They went from 6 ohms, to .4 ohms, to OL, to 23k ohms. They were all over the board. The readings wouldnt stay consistent to get a solid number. I checked the 4 I have for the passenger side to see what they should be. All our tested out from 1.2-1.6ohms. Steady readings.
I would say I found my problem. Tomorrow (if its above the -10* forecast) I will pull the passenger side wheel and well and do the other side. Ill have to wait till monday and hope one of the four dealers within 25 miles has a harness in stock.
Thanks to the write up in the tech section!!!!