Trying to change Glow Plug Relay

[Wideopen]

Does my 7.3 have 2 Glow Plug Relays??? Which one in this pic is it??? If I have 2 how do I know which is Bad... http://www.logantele.com/~pbaker/truck/Stuff137.jpg

I've got to get this thing fixed quick..won't start when its cold

Help..And no wise cracks from you Dodge Drivers


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[Max Power]

Well, I am not a diesel mechanic but I do know my way around Electrical.


Here is what I would do.

On the 2 big terminals of each relay, one will be +12v power all the time and one will read ground when the relays are off and the glow plugs are off and SHOULD read +12v when the glow plugs are on.

Now if the relays were faulty, the glow plug side will likely never read +12v.

As far as the small terminals go. I don't know if Ford uses negative or positive to engerise the relay. Either way one small terminal will read negative when the glow plugs are supposed to be on and one will read positive. Now if both read either positive or negative that likely means that either the controller for the glow plugs is shot, or there is an open circuit somewhere or a fuse or fusable link blown.

Test it out and let me know what you come up with and I should be able to provide more insight of what is going on and why. You might have to do more testing at that point as well.

Again I am not a diesel mechanic but doesn't ford use a preheater? If so, would that be what one of the relays is for?

 

[Wideopen]

that was kinda what I was thinking on the Testing Part..but I wasn't sure about the Neg or Pos. Charge..Thanks Boss

 

[Max Power]

 

[Wideopen]

O.K. now I know it is the one in the back....the one in the front is a fuel heater???..Thanks Boss Man

 

[PowerStroker444]

Yep, the one in the rear.

....the one in the front is a fuel heater???.

Yep.

 

[NemoRat]

The '95 - '97's only have one. I have never looked at the newer setup. That looks a bit different.

 

[geonc]

I've wonderd the same thing about the fuel heater.

Where would the heater be located on a '96 PSD?

I knew where the '90 was!

 

[Ramprat]

Originally posted by geonc
I've wonderd the same thing about the fuel heater.

Where would the heater be located on a '96 PSD?

I knew where the '90 was!

The fuel filter sits on it. It's a filter bowl, water seperator and heater all rolled into one unit.

 

[geonc]

Originally posted by Ramprat
The fuel filter sits on it. It's a filter bowl, water seperator and heater all rolled into one unit.

Thanky Kindly, Rampy