7.3 Powerstroke Glow Plug Relay

Posted in Ignition Systems

What does the “glow plug relay” do , on a ford 7.3 powerstroke diesel 1996 ?
engine doesnt start when first started in morn….waiting for wait to start light to go out ….then engine just turns over no fire at all ….alot of white smoke exhausting though while attempting to start….if i shoot a little ether into air box inlet it starts instantly…and will continue to start ok when engine is warmed up ….what could be the prob ?? thx has new pcm/injector module and 4 new glow plugs.

There are 4 Answers for "7.3 Powerstroke Glow Plug Relay"

    1. bitcrazy6464 says:

      the relay turns on and off the glow plugs

      if there is white smoke that means the engine is getting fuel but not enough heat to fire the fuel mixture.it sounds like a glow plug problem.on the two big studs on the relay you want to Check that one stud has power (b+)all the time and the other stud only has power(b+) for a short time when you turn the key.if you have that check the valve cover gaskets there is two plugs on each valve cover gasket that caries the power to the glow plugs they have a habit of melting and burning .make sure that you can unplug them and that they show no signs of burning or melting but don’t break the tabs .the connector is only available from international.also you can check the current of each of the two legs (left leg and right leg )between the relay and the glow plugs .if the two legs are different you have a problem(the low side has a dead plug)
      good luck

    2. QuattroCS says:

      diesels do not have spark plugs, diesel combusts by compression, the glow plug is used everytime you go to start the car, you have to wait for the light to turn off. then it starts much easier. the relay just gets the signal from the ignition instead of the glow plugs getting the power from the ignition, let me know if you need more help

    3. goodfella8243 says:

      Already answered. For more information all about your truck, join a forum/message board.

    4. Rolls-Royce Man says:

      Im wantig to say the glow plugs aren’t getting power