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High Idle...Why?

2320 Views 23 Replies 16 Participants Last post by  army
I'm picking up my Duramx next week, been reading as much info around this site as I can. I've been noticing people are installing a high idle kit. what does this do? and what does it help?

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it does just exactly that - it raises the idle speed for things such as quicker warm ups on a MN cold night, helps jump start another vehicle, provides extra current for a converter ie 12v to 120v and many more needs, but the most important thing it is real cool to do. Some have even tied it into their remote starters as well.

Engineer Bill
It's a cheap simple install that warms up your truck faster. It might come in handy in MN. I'm in Upper Michigan and its nice to hit the remote start and then trunk release button (which I hooked up the high idle to) while eating breakfast and come out to a warm truck. If you decide to do it and have any questions there's plenty of people here (including myself) that'll help ya.
Same here, these trucks just DO NOT warm up at the factory idle setting here on a Michigan winter morning. The Hi Idle is near the top of my list of mods to do.

Turbo cool down and faster warm ups !!!!! Plus the "IT'S COOL" factor ....

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MAc your pm box is full...
Is there a 2003 specific High Idle "How-To" out there? I had heard that it is a little different from the older trucks.

I followed Kennedy's detailed instructions which were for a 01-02 truck and had no problems with my '03. I think the only real difference was the ECM connector color if I remember right. They are labeled though so you can figure it out from there. Other than that it's pretty straight forward. Edited by: Minn-Kota

Look under the "Do it Yourself and Useful Articles" section. Station10fd posted some excellent pictures of a High Idle install.
His truck is a 03 and he didn't report any problems. Hoot also provides a link to the instructions originally posted @TDP by mdrag. I hope to complete my install this weekend. The pictures are already a help. It's nice to see what things look like before you start.


Edited by: HisDMAX
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Thanks for all the reply's...

Keep us posted on how it goes this weekend.

It sounds like something I should have, being in MN. So, What's the best system and who sells it?
It is something that gets programed in? or how's it work?
Thanks again,


go to this previous post for your answers:


Engineer Bill
I offer a prepared wire with the correct terminal for the pcm connector.

dmaxalliTech said:
I offer a prepared wire with the correct terminal for the pcm connector.


how much and how do i get one??
I thought that heated garages were used to keep them warm at night and use the block heater at work.

Heated garages!

What are those?

Dmax Tim said:
I thought that heated garages were used to keep them warm at night and use the block heater at work.

???? my heated garage if for the toys that the Dmax hauls, no room for the dmax in there with all the other toys!!!!
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I've heard that the lead to the ecm "c71" is present on the pto connector that resides behind where the pto switch would be. i've found the connector but don't know if this is true and if it is what color wire? This would be much handier for the install if you don't have to remove the tcm and ecm and run the wire in. Anyone know about this ? Thanks in advance!
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Not exactly. You're correct that the connector is there and it has the light green wire that should be run to C71. However, that wire terminates at another connector (C106) located on the front of the under hood fuse block. You'll still need to connect that wire to C71.
Thanks Bigrazor- I thought it sounded too easy anyway!
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