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GM guys...VYU..Pkg..Hole in firewall?

Discussion in 'Commercial Snow Removal' started by TLS, Nov 15, 2004.

  1. TLS

    TLS PlowSite.com Addict
    Messages: 1,425

    I'm currently installing a BOSS V-Plow in my '04 GMC 2500HD. Figured I'd tackle some of the wiring tonite. Start looking for this 42mm hole and grommet.

    I cant find one!

    (YES,....I DO have the VYU package.)

    At least one without something already passing through it. My throttle wires pass through an approx 1.5" rubber grommet in the same general location that the plans on the GM Upfitter site indicate. I see nothing anywhere indicating that I'd be "sharing" a grommet with something as important as my throttle wires.

    The only other big grommet thing has the BIG monster wire loom through it. It is about a 3" hole through the firewall. This, I'm sure isn't it either.

    Then under the dash, I see this little handle that I pull and whammo, a 2" round piece of plastic firewall barrier comes peeling out. Behind it.....the metal firewall. No 42mm hole, just a little centerpunch dimple that I can barely feel.

    Did they (GM) forget to drill the hole through the firewall?

    Does anybody have any suggestions here?

    Also,......anyone have good suggestions on where to mount my solenoid or my row of 4 relays? Not much flat un-obstructed room under there anymore!

    JKOOPERS Senior Member
    Messages: 112

    i ran onto the same problem with the firewall . i just made my own hole . as to the relays you wanna keep them close to battery. i actually put mine on the firewall in the engine compartment
  3. TLS

    TLS PlowSite.com Addict
    Messages: 1,425

    You made your own hole, but isn't the VYU supposed to come with one already there? Do you have the VYU package?

    Where on the firewall? Around the master cylinder? How about the solenoid?
    Last edited: Nov 16, 2004
  4. richardlewis

    richardlewis Member
    Messages: 37

    I don't think there is one at least I couldn't find one on my 2004 Chevy. I ran it threw by the steering column
  5. flykelley

    flykelley 2000 Club Member
    Messages: 2,124

    Guy's on my 2001 Chevy 3/4 HD its on the left side of the steering column. Its about 1 1/2 inch more or less. I heard somewhere that GM was not going to drill the hole any more. I do work for GM truck Div but I'm not at the assy plant any longer. I will try to make some calls and see if I can get a answer.

    Regards Mike
  6. TLS

    TLS PlowSite.com Addict
    Messages: 1,425

    Thanks Mike.
  7. TLS

    TLS PlowSite.com Addict
    Messages: 1,425

    Here is a pic from under the dash.

    Last edited: Nov 16, 2004
  8. TLS

    TLS PlowSite.com Addict
    Messages: 1,425

    And here is the pic from under the hood.

    Any suggestions guys?

    From the looks of GM's diagrams, it "should" be the small grommet with the throttle wires coming out of it.

  9. Bad Luck

    Bad Luck Senior Member
    Messages: 741

    TLS - I did not have one but my truck is only a 1500. I drilled a hole, looking under the hood, just to the left and above where the steering column comes through, in beween the steering linkage and the engine. I had a spot where there was no insulation. Under the dash in this spot there was no plastic or insulation as well. I hit it with a 5/8's drill and whamo, there was my hole. I mounted my relay on the lower part of the under hood fuse box. There is nothing behind the hard plastic, it seems pretty stable. You may also want to check out just under the battery the PCM cover, it comes off, I mounted my iso module there. Check my install thread for pics.
  10. ratlover

    ratlover PlowSite.com Addict
    from IL
    Messages: 1,325

    They stoped drilling it in 03 I believe. I had to drill a hole :mad: The place on the inside of the cab were there is a hole in the insulation(your pic) is the place it used to be and were I drilled.
  11. flykelley

    flykelley 2000 Club Member
    Messages: 2,124

    Ok here is a picture of my hole,2001 Chevy HD. The hole is already filled woth wires but look for the blue loom and the bundle of gray wires for my strobes.


    firewall hole resize.jpg
  12. 04chevyboy

    04chevyboy Junior Member
    Messages: 1

    hey guys im installing a cb radio. any chance there is a grommet located on the passenger side of the truck? its an 04 silverado 1500 with the console in the middle
  13. Burkartsplow

    Burkartsplow PlowSite Veteran
    Messages: 3,248

    i have one on my 04 near the pedals.
  14. Brant'sLawnCare

    Brant'sLawnCare PlowSite.com Addict
    Messages: 1,748

    I've had to drill holes in at least one of mine. Not sure about the other one.