intermittent electrical
 

Hello
I have a 2002 F350 superduty XLT 4x4 with a 7.3L power stroke.
When I go to start the truck, the dash warning lights flash on and off and I here what sounds like a relay vibrating/buzzing noise under the dash. The glow plug light does not extinguish and the truck won't start. Turns over good but no start.
If I put my foot on the brake everything works 100% normal. As soon as I release the pressure off the brake it stalls. If I,m quick to put the pressure back on the pedal it keeps running. If I ride the brakes I can drive the truck.
This problem is intrmittent and never dupicates when I've had it at the Ford Dealer.
There are no fault codes showing. New battery's and new Alternator. They also replaced the DPFE 3 sensor assembly.