After looking around for a long while, and not really finding a really good post on this mod, I got around to giving it a try..This is the high idle mod..
With a wiring diagram manual for my 04 X(and SD trucks) I had the confidence to go forward with this..My truck is an 04 with 03 engine..I don't know if this works on 05's..If you fry something don't come crying to me..
The manual showed the pin position on the PCM for the +12vt signal input..Just as i've read in the past, there was no wire in the harness or PCM connector for the input..I had to make one myself...
I pulled the driver's battery connections and cover..The SEIC input is in the rearmost PCM connector..The back of the connector will pry off easily with a slotted screwdriver after it's pulled from the PCM..Work it at each corner..
I decided to use a small red spade connector to make the wire to PCM connection..
I cut off the red insulation and gently crushed the round wire recepticle to make it a little oval shaped...The pin you are connecting to is rectangular..Then I trimmed the spade portion of the connector to match the width of the recepticle end...After that i soldered a small 20GA pigtail onto what was left of the spade of the connector...It isn't pretty, but it fits into the PCM connector and mates nicely with the pin in the PCM..
Now I had to get my makeshift pigtail into the connector...I used a small drill bit to go all the way through the connector and fish the pigtail out the back..Be carefull not to hit the other wires when drilling through..
Here's a good pic of the back of the harness for the pin location..The new wire is the blue one..
After I got it all in there I plugged back into the PCM and gave it a test by starting the truck..The first key cycle, no starter..Tried a second time and it started right up...I guess it was because of disconnecting the batteries..I tested by touching the pigtail to the + side of the battery...Engine rolled right up to 1200 rpm's just as I hoped..
Since it was working, I put a little glue in the hole I drilled into the connector for the wire..
I still have to wire in a switch on the dash to finish up..That's the easy part..I'm just glad it worked without the PCM going POOF!!
on edit: switch is in.. all is well!!