The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - How to Drill Doors and Jambs for Loom Install?

sprint_9 · 11-06-2019, 07:46 PM

I will try to explain how I did mine, I thought it turned out pretty good and everything installed and is operating good.

I drilled the holes behind the dash so they would be above my vent, and centered in the pillar. On my truck on the passenger side the dash had a hole already present in the dash panel where its bolted to the cab on the backside of the dash, all I had to do on that side was drill the cab metal. On the drivers side I had to go through both pieces. You can look for that hole and see if you have it, my truck was a 72. I dont have any pictures of the passenger side, only the drivers but it gives you an idea. If you dont have that hole in the dash panel then I think you can also look for the spot welds to make sure you can get centered in the pillar.

From there the wires route through the pillar to the standoff on the pillar for the door switch. I chose to drill the hole to my door inline with that it since all the wires will run together.

On the door Im not sure how you will be able to drill on the truck, I think it would next to impossible since the inside support is angled and there is very little room to work from the inside of the door. You could try to go farther to the outside edge of the door to where it is flat I suppose.

I drilled with my doors off. I previously mocked up the wire conduit and figured out how it would best lay. I then marked on the door where my hole would need to be and removed the door to drill. I drilled everything from the outside in. Starting with the hole that the conduit would sit in, I think my conduit called for a 7/8 hole. Once that hole was drilled I took a 5/8 bit and drilled at the correct angle of the inside piece so the drill was square to the inner panel.

For wire protection I found a plastic bushing and inserted it into the inner brace of the door. The conduit provides wire protection exiting the cab and entering the door. Behind the dash I used a rubber grommet. I drilled holes in the inner door panel to bolt some clamps to, and all the wire is loomed with either braided loom or split loom.

Pictures are,

Behind the dash hole. Conduit exiting cab.

Holes drilled into door. Everything installed.

Inside the door.

11-06-2019, 07:46 PM	#4
sprint_9 Registered User Join Date: Nov 2012 Location: 9 Posts: 862	Re: How to Drill Doors and Jambs for Loom Install? I will try to explain how I did mine, I thought it turned out pretty good and everything installed and is operating good. I drilled the holes behind the dash so they would be above my vent, and centered in the pillar. On my truck on the passenger side the dash had a hole already present in the dash panel where its bolted to the cab on the backside of the dash, all I had to do on that side was drill the cab metal. On the drivers side I had to go through both pieces. You can look for that hole and see if you have it, my truck was a 72. I dont have any pictures of the passenger side, only the drivers but it gives you an idea. If you dont have that hole in the dash panel then I think you can also look for the spot welds to make sure you can get centered in the pillar. From there the wires route through the pillar to the standoff on the pillar for the door switch. I chose to drill the hole to my door inline with that it since all the wires will run together. On the door Im not sure how you will be able to drill on the truck, I think it would next to impossible since the inside support is angled and there is very little room to work from the inside of the door. You could try to go farther to the outside edge of the door to where it is flat I suppose. I drilled with my doors off. I previously mocked up the wire conduit and figured out how it would best lay. I then marked on the door where my hole would need to be and removed the door to drill. I drilled everything from the outside in. Starting with the hole that the conduit would sit in, I think my conduit called for a 7/8 hole. Once that hole was drilled I took a 5/8 bit and drilled at the correct angle of the inside piece so the drill was square to the inner panel. For wire protection I found a plastic bushing and inserted it into the inner brace of the door. The conduit provides wire protection exiting the cab and entering the door. Behind the dash I used a rubber grommet. I drilled holes in the inner door panel to bolt some clamps to, and all the wire is loomed with either braided loom or split loom. Pictures are, Behind the dash hole. Conduit exiting cab. Holes drilled into door. Everything installed. Inside the door. Attached Images Last edited by sprint_9; 11-06-2019 at 07:52 PM.