I posted this on Ask the Techs and didn't get an answer. Maybe one of you guys can help out here.http://www.dieselplace.com/forum/smileys/Big Smile.gif


I have the Prep Package on my 2004 GMC Sierra. Where the heck is the hole in the firewall supposed to be to run the plow controll wires??http://dieselplace.com/forum/smileys/Ermm.gif Any Pics. would be apprecciated. The owners manuel is not much help.http://dieselplace.com/forum/smileys/Cry.gif


Thanks


Cosgrovehttp://dieselplace.com/forum/smileys/HiHi.gif

I don't think there is one, I had to drill one

Gearhead


Did you drill the hole through the firewall where there is no insulation by the Master cylander.. I think that may be the palce.


Thankshttp://www.dieselplace.com/forum/smileys/Clap.gif


Cosgrovehttp://www.dieselplace.com/forum/smileys/Big Smile.gif

there is a hole in the insulation toward the center of the firewall left of the master cyc.

Does anyone know where the wire is for roof light in the snow prep package?

not sure but I think it is above the headliner, maybe?

The harness is located toward the rear of the cab above the headliner. It is bundled up there. Pull down the headliner a bit and start fishing with a coat hanger....IIRC It should be a brown wire and a black wire...

Gearhead


Did you drill the hole through the firewall where there is no insulation by the Master cylander.. I think that may be the palce.


Thankshttp://www.dieselplace.com/forum/smileys/Clap.gif


Cosgrovehttp://www.dieselplace.com/forum/smileys/Big Smile.gif

I always find a place inside cab that I want wire to come through at them double check in engine compartment to make sure there are no issues with the location.

I fished my wire for the becon out from under the 3rd brake light so i didnt drill any holes. Also coulda weaseled it out the plasic vent grate deal in the back of the cab between the cab and bed


What kinda plow you going to run?

The easiest place to drill through the firewall is where there is no insulation on the firewall above the engine between the center of the engine and the master cylinder. There's a round cut out of the insulation there about 2" in diamater.


If you look on the inside of the cab in the same spot you will see that the insulation is missing there too.


Take a hole saw and cut out as big a hole as you need. I did mine at 1-1/4". The firewall is real thin at this spot so you wont have to drill hard to cut through. And watch the wires on the other side.


I THINK the plow prep package comes with the hole already drilled and a solid rubber grommit installed in the hole which you would cut out with a knife to run the wires through.


Good Luck

I use a 1" hole saw and I insert a rubber gromment into the hole after it is bored.