I have a 1993 ford f250 with the 7.3 idi. It was all fine until a couple weeks ago when it started hard starting. I assumed glow plugs as opposed to an air leak or something like that so I changed them all out. Truck still wouldn’t start, found an air leak around an injector and solved that issue but still no start. It would click for a while when the key was turned to the on position so now I assumed the co troller was dead. Instead of buying a new controller, I rigged up a pic button start in the cab and the truck fired right up. Worked fine for three starts until today when it failed to crank again. I assumed I hadn’t held the button long enough so I tried again and still nothing. Fearing burned up plugs I gave it a huff of starting fluid and it started up.

sorry for the long winded response but this is frustrating, I smelled something getting hot in the cab so maybe one of my connections? I can see the voltage drop when the button is pushed so something is getting power Not sure any info will help. Thanks

 

what brand glow plugs did you use? anything other than motorcraft ZD-9's and they are probably burned out already.

 

Not sure, ordered a set of 8 off of diesel logic.com. I took one out and inspected it and it seems fine. The ones I tested had around 1.1 ohms of resistance, is this too high?. The relay clicked excessively before I did the push button swap so it’s probably dead. Would a dead relay still effect the plugs even with the manual override. Like I said it started fine 3 times.

 

I popped one out and turned on the controller to see if it got red, no change glow plug was cold to the touch after.

 

you are lucky you got three starts out of them. most only work one time.
rock auto has the motorcraft ZD-9 plugs for $9.45 each
https://www.rockauto.com/en/cart/

 

thank you so much, I’ll order the new ones and get it all fixed up