Have 99 7.3. Truck lost power. Now won't start. No power to fuel pump. No wts light. Tach not moving. Reset button good. No oil on icp plug. Oil level good. 30 amp fuse good. Engine cranks over good. No access to good scanner and nearest dealer about 100 miles away. Cleaned screens in mixing chamber. They were plugged. Any ideas?

 

Welcome to FTE.

No WTS light is fuse #30 under the dash. It blows when the fuel bowl heater shorts out. There is a plug on the back of the fuel bowl for the heater, unplug it, tape it up and leave it that way. Now replace fuse 30 and try and start the truck.

 

You say “no power to fuel pump”.
When you turn the key to the ON position do you hear a humming/buzzing sound under the drivers seat area?
The fuel pump is on the drivers side frame rail and will run for about 10-15 seconds and shut off.

Welcome to FTE!

 

30 amp fuse is good. Test light to pump shows no power.

 

#30 fuse. In the fuse box below the steering column. It’s good? Checked with a meter? Sometimes just looking at the fuse it can fool you.
Can you hear the fuel pump run/come on when you turn the key to “run”?

 

Fuel pump not working when key turned on. Going to put another fuse in now and see what happens.

 

Fuse is good.

 

. And…? ........

 

No change. Still no wts light. No tach movement. No power to fuel pump. I will add another detail. Originally I thought it was fuel pump. Wts light was still working. I installed new fuel pump, didnt test for electricity so when pump wasn't working I thought it wasn't getting fuel so I dropped the tank and cleaned mixing chamber screens. When it still didn't pump, that's when I discovered no power to pump. I ran a live wire to pump and truck fired up and ran good. I switched key off, but truck kept running. At the same time, the electric transfer case switch wouldn't work. I pulled live wire off pump to shut it down and that's where I am at now.

 

OK unplug the EBPS and see if the pump starts

 

Won't be able to get back at it until tomorrow morning. Thanks for the info.

 

If you have a way to check vRef see if you have about 5 volts, if not it could be a sensor shorted and dragging vRef down which will disable the PCM. Start unplugging sensors while watching vRef to go to about 5 volts, start with the EBPS because that one has been known to short out, especially a non-OEM one. It can also cause low power which you reported just before it quit running.

Also check the collision fuel shutoff switch and see if there is power on the incoming side

You don't have a chip installed do you?

 

I will have to research on how to check vRef. I don't know if truck is chipped. How can I tell? It did seem that the truck had more power than other 7.3 power strokes I have run but there is no dial or switch like one truck I had.

 

look on the pcm connector for a chip. vRef can be checked with a volt meter, each sensor receives 5 volts just a question of which pin it will be on. https://www.searchautoparts.com/moto...esels?page=0,3 I'll be travelling all day today hopefully the guy's here will steer you right and get it going