I have a question. I have an 04 F350, and I see a lot of guys doing a high idle mod on there trucks, but i wonder why do this if the truck already idles high when its certain temps outside. Mine normally idles @ 650-675 and if its cold it automatically jumps to around 1000 RPM. So does everyones not do it automatically? Is it safe to put this mod on the truck even though it idles automatically?

 

I believe the automatic high idle is a later programming flash, but mine does it too. I was all set to do the high idle mod but when it got cold I realized that mine has the automatic high idle, so I didn't bother. There are other reasons to have a switchable high idle for work trucks, trucks that idle a lot, that have a PTO function, but mine has none of those so I just left it as it is.

Brian

 

As i remember there are two different settings for forced or manual high idle. One circut is for PTO usage and the other is called BCP Battery Charge Protect. They both ramp up the rpm's higher than the auto idle increase. I used the BCP wire for mine.
I use it for any idleing longer than 5 min. Winter use to keep it warm for extended idle and in the summer to keep the A/C spun up.

 

Sorry I never really answered you question, I think the best reason to high idle is to keep engine heat up for extended periods of idleing so the EGR valve will not soot up as fast as it would under lower eng temps.....

 

All good answers above. I use mine when jumping someone off too.

 

Just remember:

05-07's have the 2 different ways to do the high idle.

The 03-04's only have one way.

Food for thought.

 

If you do the aftermarket high idle mod, it will automatically jump to 1200rpms when you hit the switch. Unless youre in cold weather (under 20*) id say 1200rpms is HIGH. But in that weather it can warm things up and unstick egr and turbo n whatnot.. but im on the east coast and it never gets below 30* and i dont like to idle for long at all, just enought to get the tranny up to the 70's.. So 1000rpms is a good high idle for me.

 

my 06 will automatically increase rpm at idle when cold. dk what rpm, i just heard it when hooking up a trailer.

 

My understanding is that the high idle mod will prevent "wet stacking".