i have a 1999 F550 7.3. the starter went bad so i replaced starter and starter relay, (was told both should be replaced together). after replacement i used the truck for a day, turned the truck on and off probably 30 time that day and had no problems.
the next day when i went to start the truck it would not start. when i turned the ignition all the lights came on but when i turned the key to the start position nothing happened. i used a screwdriver to see if maybe it was the relay and i was able to start the truck by jumping the relay. i figured it was in the switch, so i put a aftermarket starter switch in, by running a hot wire from the engine comparetment fuse panel to the aftermarket starter switch then to the relay. it worked fine to start the truck.
i noticed that after i did this the glow plug wait light would not come on when the ignition was turned on, and the truck would not start anymore.
what are any suggestions to fix this problem?

 

I am not sure that I am following all of your wiring changes. Does the starter turn over but the engine just won't fire up?

If it cranks, and this would be purely coincidental, check the large #30 fuse. It powers both the PCM and fuel bowl heater. If the PCM has no power, the WTS lamp will not be visible.

Getting ahead of myself here but if the fuse is blown, unplug the fuel bowl heater, replace the fuse and try to start it again.

 

Presently I have a simular problem - maybe ? I didn't bypass any wiring and all. I had a no start conditon. I noticed the wait for glow plugs light was not working and the light for my OD on the shifter was lighted in "off" position.
I found there is a fuse in the bottom right corner that keeps blowing. The 1st time I replaced the fuse everything worked for a few days. Now it blows the fuse the minute I turn on the ignition. I don't have the operator manual but I suspect the fuse if for my ECM and ???
I'm also looking for something that may lead to the short causing my fuse to blow.
ROBIN - I will tell you from my expereince - I wouldn't be bypassing and adding extra switches to cure a unknown problem - it only complicates matters.

 

If that fuse is a maxi-30 amp fuse, your fuel bowl heater is shorting out.

 

i had a similar issue and what was found was the fuze block was messed up. over time (ive only had truck for about six months) past owners had wedged pieces of metal in to fuse slots to jump them out (rather than buying new fuses) and it caused them to be loose

 

Ya dug up a old one there!!! LOL

 

Hi, did you ever find out what fuse that was and did it fix the issue? I am having a similar issue. Truck just quit, the OD light is on in off position and the wait to start light is not coming on.

Thanks Ron,