That is what the first (large) diagram, that I posted, shows. The GPR works the same way, but has no sense (feedback) wire, on the "load" side, back to the PCM. The voltage signal tells the PCM that the AIH is energized.

 

Pete, this might answer your question. On a E99 you cannot do a CCT with AE, because there never was a AIH or any support for it from the PCM. So I would assume if you delete the relay and the blue wire you would loose the ability to do a CCT.

 

What would happen if you moved the AIH signal wires to the glow plug relay. I noticed the signal wire colors are the same on both. Would it give the proper signal so it did not throw the soft code or would it screw something up?

 

Given that the AIH and GPR work under different conditions, I'm not sure I would want to try that for the risk of potentially confusing the PCM. I am NOT a PCM expert by any means, though, so that is simply my first thought/reaction which is based on limited knowledge of the PCM's inner workings.

 

Attaching the powerpoint pdf of this GPR relocation to the passenger fender to this thread. SpringerPop has it on his website as well. I just reviewed it after being away from this forum for awhile. It doesn't really stand alone, given all the good info many have added in this thread, so I wanted to include it here. Hope it's useful to you. Damn I miss that truck.

I see a few have implemented different methods to incorporate the Stancor/White Rodgers relay in the valley and on the fender with good results since this thread started. My situation was a little unique, having changed to manual hubs and deciding to remove the PVH solenoid. Regardless, I sure appreciated the improved visibility for leaks and access this mod provided.

 

Here is a link to the photos in my Album where I moved mine to the fender. Not nearly as detailed as Jeff's document, but this is another way it can look for a 2WD application where you don't have to fiddle with the vacuum system.

https://www.ford-trucks.com/g/album/2843812

 

I like what you've done to keep the terminals away from the fender metal. Amazing the space the 2WD trucks have there.

 

The space is nice, for sure. What's nicest for me, though, is that since the new GPR is hard-mounted to the fender steel, I no longer need to plan on installing the LED mod. Every time I start the engine, I always wait to pull off until I know the GPR has deactivated, and I know when that happens because I hear a very noticeable and loud CLICK sound when the GPR relay switches off!

 

I remember that sound - loved that strong tactile feedback. I was using the Innova voltmeter at the time too, but didn't need it to know that the badass contactor had disengaged. Makes me weep...

 

I might just be talked into selling mine to you if you miss it that much.

 

Don't tease me! I do miss it, but much of the satisfaction I got from owning and working on it was the family I interacted with at FTE. Realize that now more than ever. I gotta wait awhile and educate myself on everything y'all have learned while I was checked out these past few years. I'd like to implement the GPR mod on the next rig, that's for sure.

 

Well, Jeff. I certainly understand. If you do decide to get back in the 7.3 game, let me know, because we just might have something to talk about offline.

 

So what I'm reading is you never came up with a method to eliminate throwing a code with the AIH relay removed......correct? Even with a Bosh relay and a 470 ohm resistor? Did I miss where you came up with the 470 ohms? Is that equal to the resistance in a good working AIH?


.

 

That's correct - I did not get the AIH soft codes to go away. If I remember right, I played with it a bit and decided it was not worth the effort to get the CCT working. I didn't play with the Bosch relay though. I think the 470 ohm resistor was chosen as a convenient signal resistor for a 12V system sense line. We used them to eliminate the PVH soft codes successfully. The actual AIH resistance would be much lower - an ohm or 2, to get the watts needed to heat that intake air.

 

I noticed that the AIH draws 58 Amps GPR AIH Relays . I wonder if the PCM is sensing the slight voltage drop as a result of the 58 amp draw from the heater when the relay is activated. Considering they didn't connect the (Blue) PCM sensing wire to the relay coil activating source (Relay Post 86, Wire 462 VT), it leads me to believe it has something to do with the actual voltage change from a working heater. If my theory is true the PCM would be getting its comparison voltage from a second sensing wire directly from the Alternator. (Which I have not tracked down yet).

There has to be a way of fooling the PCM into thinking their is a 58 amp draw taking place when the relay would normally be activated.