Why AIH Delete
Fleet Mechanic
Joined: Apr 2011
Posts: 1,441
Likes: 6
From: Marseilles IL
I had never heard of the AIH delete until I bought my gauges from Clay at RRE a few years ago. JD gave me his old homemade AIH delete plug with fitting for boost pressure gauge and it seemed to make the install much easier than tapping in anywhere else. My only word of caution is that if you remove the AIH, don't remove the bolt that the ground wire runs to on the drivers side valve cover. We did, thinking the bolt hole was a blind hole, but in my case it wasn't and I drove around with a hellacious boost leak for a few months until I realized what I had done.
Cargo Master
Joined: Feb 2005
Posts: 2,837
Likes: 1
See this thread. I can't view the pictures at work, but I'm fairly certain it should answer your questions:
https://www.ford-trucks.com/forums/9...with-pics.html
https://www.ford-trucks.com/forums/9...with-pics.html
Fleet Mechanic
Joined: Apr 2011
Posts: 1,441
Likes: 6
From: Marseilles IL
I have that same code eliminator wire and installed it as described and it doesn't work. I still get the code.
To be honest, I still can't figure out how that code eliminator wire would help when placed like the instructions say. Seems to me that the wire should have a big resistor inline and connect the large terminal on the AIH relay to the wire from the engine harness. However, I've never tried it for fear of frying my PCM.
Looking at the OEM set up...there are two wires connected to the heater. One wire comes straight from the AIH relay (heavy gauge wire). On the same stud, but separated by an insulator, there is another wire that runs to the engine harness on the driver's side. What happens with that wire? I presume that is the wire that runs to the PCM and wants to see resistance through the heating element so shouldn't that wire be fed a resisted power signal to eliminate the code?
To be honest, I still can't figure out how that code eliminator wire would help when placed like the instructions say. Seems to me that the wire should have a big resistor inline and connect the large terminal on the AIH relay to the wire from the engine harness. However, I've never tried it for fear of frying my PCM.
Looking at the OEM set up...there are two wires connected to the heater. One wire comes straight from the AIH relay (heavy gauge wire). On the same stud, but separated by an insulator, there is another wire that runs to the engine harness on the driver's side. What happens with that wire? I presume that is the wire that runs to the PCM and wants to see resistance through the heating element so shouldn't that wire be fed a resisted power signal to eliminate the code?
Fleet Mechanic
Joined: Apr 2011
Posts: 1,441
Likes: 6
From: Marseilles IL
I cannot post pictures but the relay is on top of the passenger valve cover. It's the relay towards the front of the truck. The big stud should have a small blue wire on it and if the heater is still hooked up there would also be a big red wire going to the heater element.
Senior User
Joined: Oct 2009
Posts: 411
Likes: 1
From: Plant City
I just followed the instructions at clays site. Worked find for me.
http://www.riffraffdiesel.com/mm5/RE...s_AIH_PLUG.pdf
http://www.riffraffdiesel.com/mm5/RE...s_AIH_PLUG.pdf
Senior User
Joined: Dec 2010
Posts: 198
Likes: 0
I just read this entire thread and i am not sure on if my question was answered or not.
If i do an AIH delete on my 03 7.3L will it turn my check engine light on? Will it screw with my tunes as well?
If i do an AIH delete on my 03 7.3L will it turn my check engine light on? Will it screw with my tunes as well?
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Veteran/Sheepdog
Joined: Feb 2012
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From: Western AR
Cargo Master
Joined: Feb 2005
Posts: 2,837
Likes: 1
You won't notice any performance gains, it's more just a peace-of-mind thing knowing that the little bit of airflow restriction is no longer there. In my case, it was just easier to do the AIH delete and use that hole for my boost gauge.
j/k
Postmaster
Joined: Jun 2010
Posts: 2,555
Likes: 8
From: Longview, TX
If you get gauges from clay, the 3 and 4 gauge kits contain the delete plug with the boost sensor tapped. I actually don't think the AIH causes that much restriction as far as mass flow rate, but it does cause turbulence in the flow. If it was a non-turbo truck I imagine that much reduction in cross section and turbulence created would be bad.
On another note, I have the boost line ran to the AIH delete plug with clays kit because it was easy. That number gives you pressure directly before the engine. What does that tell us? Not much. The reason we monitor Boost is so that we don't destroy the turbo. So we want to know the pressure directly out of the turbo before the pressure drops through the intercooler and IC pipes. It really doesn't matter to most of us, there should just be a few PSI difference, and the trend is what we are looking for. If you want to be really accurate and watch what the turbo is really producing, tapping the spider on the hot side is what you want. If you want ease of installation and the ability to follow trends, the AIH is a great option, and works well for the vast majority of us.
On another note, I have the boost line ran to the AIH delete plug with clays kit because it was easy. That number gives you pressure directly before the engine. What does that tell us? Not much. The reason we monitor Boost is so that we don't destroy the turbo. So we want to know the pressure directly out of the turbo before the pressure drops through the intercooler and IC pipes. It really doesn't matter to most of us, there should just be a few PSI difference, and the trend is what we are looking for. If you want to be really accurate and watch what the turbo is really producing, tapping the spider on the hot side is what you want. If you want ease of installation and the ability to follow trends, the AIH is a great option, and works well for the vast majority of us.
Fleet Mechanic
Joined: Nov 2008
Posts: 1,573
Likes: 4
From: Seattle