another glow plug issue

[350dieselsmk]

Hey guys,
Haven't posted on here in forever. my gloplugs in the truck are way out of whack. both of the replays in front of the turbo have power on the line side and nothing on the load side when the key is turned. some times when it is around 60 degrees out side the glow plugs will kick on but other than that i have nothing. its going to start getting colder and i am going to need them soon. anyone have an idea of that it could be? i don't want to go and buy a new relay right away because both of the relays are doing the same thing which makes me think it could be something else. i know one of the relays is a glow plug relay not sure what the other one is.
any ideas would be awesome
thanks
Will

[docweld]

the other one is for the heating coil in the spider.

[stroker0920]

The second relay is for the AIH (Air Intake Heater). Like docweld said, it is in the spyder. It usually doesn't kick on until certain requirements are met. This is what riffraff diesel says the requirements are:

Ambient temperature must be below 32°F
Engine oil temperature (EOT) must be below 131°F
Vehicle power must remain between 11.5 and 15.0 volts
Parking brake must be applied
The transmission must be in Park or Neutral
Glow plugs must be off

From what I've heard is it is basically there to clear up any white smoke after cold start ups.

[NoRalPh]

Read through this to diagnose if you are having a problem or not. Also realize that the WTS light and the relay are in NO Way connected. It's ON when the GPs are Off sometimes and OFF when they're On sometimes

Troubleshooting GPR & GP's

[350dieselsmk]

if it is infact a pcm problem what action do i take? dealership?

[NoRalPh]

I'd be sure it wasn't the wiring first though, trace it right up to the PCM connector, see if the PCM itself is supplying a Ground Path or not to the relay..

Then, either spring for a whole new PCM (ouch!) or make your GP system a Manual one with a switch You control to engage the relay.

[DenverDieselMike]

i have a 03 7.3 powerstroke and i pulled the valve cover off to see if my injector harness was unplugged, but instead i found a glow plug blew out of the hole (dummy before me didnt torque down tight) and i have a big dent in the top of the valve cover and the connection from the harness that plugs on the tip of the plug is destroyed, can i just splice in to change the one glow plug connector or do i have to get a new harness and wires for all 4 GPs?

[350dieselsmk]

any one know of a good manual glow plug switch write up? ive linked mine back to the pcm.

[NoRalPh]

Shouldn't need much of a write-up,, pretty simple thing to do.

The 2 sm terminals on the relay are for energizing the magnetic coil in the relay (that causes the contacts to close and power the GPs). One of them has battery power (+) to it with the key ON. The other one supplies Ground (-) to complete the circuit (Violet maybe, disconnect them both to see which one has the (+)) and is all the PCM does to turn them on. It supplies Ground to that relays coil.

So, all you need to do is to have a toggle sw in the cab that takes that wire that was going to the PCM (-) and grounds it when you need the GPs. It would be nice to have some sort of indicator light that let you know they were on, so you don't forget and leave them on...

On a cool morning, flip the sw for around 30 sec before you crank. In the summer you shouldn't need them at all, in the Winter let them run for a min or so before you crank and another min after it starts. You'd be your own PCM!

[NoRalPh]

Another thought... Before calling the PCM the problem, it makes the decision for using the GPs based on the EOT sensor (Engine Oil Temp) in the back of the HPOP res. IF that were bad, it's possible the PCM just isn't "aware" it should be using them...