Hey yall, my friend and I mounted some lights behind my grill yesterday. Well today we went to try and wire them and cannot find an easy way to get through the firewall. Does anyone have some insight on how to get the wires into the cab? I searched a number of times and couldn't find any sort of diagram or anything. Trucks a 2005.

Thanks yall,
-Barrett

 

My '99 has a rubber grommet next to the brake booster ... did you look for anything like that in your truck? (I know it's a different model)

 

Your truck's the same as mine, Barett. There are two rubber plugs on the driver's side, similar to what fairlaner posted. One is up high, next to the brake booster like his and I ran my video feed from my backup camera through that one. The other is almost directly below it but way down.

- Jack

 

Do you cut a hole through the plug or do you need to remove it?
Also not entirely sure where the brake booster is located.

 

The best route through the grommet is to push through with an awl or ice pick, and attached the wire and pull back through. This way the rubber is as tight around the wire as it can be.

The brake booster is in the engine compartment, the other side of the fire wall from the brake pedal ( the rod the pedal pushes on is inside the brake booster ).

This makes the grommet higher than the pedals, and almost center between the brake and gas pedals if I recall correctly ( did it some time ago, you might have to pull the carpet back a bit for the top one, and the lower one is way under the carpet.

 

I think it's more like "sound padding" up there SSCULLY. In my case, it was already cut out in about a 3/4 circle, so it was easy to pull back away from the hole in the metal that was exposed with the rubber plug out. I removed my plug when I was trying to see where it entered from the inside of the cab.

Agreed, something that makes a small hole is ideal, and I certainly tried to achieve that with a small bore drill. However, the hole up high doesn't get much debris splash, which is one reason I chose it over the lower one. Unfortunately, I had to feed an RCA plug through that hole, so it ended up being a bit larger than the wire that's through it now. Bare wires would be a piece of cake

Mine would be easy to reseal with the "paint on" insulation coating (the correct name's escaping me now due to advanced senility), and someday, I should fix that slightly "too large" opening.

- Jack

 

getting out of my truck earlier I found the hole yall are talking about. Mine appears to be like JackandJanet's: it is cut into about a 3/4 of a circle. Hopefully I get time in the next couple days to figure out what to use to make the hole and how to get wire through it. Does it make any kind of difference punching a hole from the inside of the cab as compared to starting from the outside? Also, is it easier to find the hole from below the truck or looking down into the engine bay.

 

I like SSCULLY's idea of an icepick since you're just poking wires through. Do it from the engine compartment (topside). Just push the wires through (once you've made the hole) far enough to find them inside the cab, then pull them through from in there.

- Jack

 

Liquid Electrical Tape, a.k.a. Tool Handle Dip Coating.

Another way to do it is to add a terminal to an empty position in a factory firewall connector, much like these captions describe:



Yet another would be to add a wire to a pass-thru grommet (not as common on your newer trucks as on my antique) by using a blunt probe (bamboo skewer) to pierce the wiring bundle & create a little more room to pull the new wire through.

The last (and probably WORST) way would be to route the wire thru the door opening & simply tuck it behind the door seal on its way from the fender to the dash.

 

Thanks, Steve - don't know why I couldn't think of the name.

However, a better way to seal up an opening in a plug or grommet I think is to use Black Silicone Adhesive Sealant. Permatex makes one variety and it comes in a tube you can buy at any auto parts store. I should have thought of that before this too. *shrug*

- Jack

 

Silicone doesn't adhere to vulcanized rubber very well, especially in the presence of liquids that "wick" (like oil, ATF, DOT3...). But RightStuff will never let go.

 

Got my way through the firewall, went through the top plug near the brake booster. Thanks y'all.

But I have another question: where would be the best place to mount a relay for the lights? Or is a relay not necessary?

Oh and Fairlaner: I went through the same grommet you went through. So yes it appears to be the same. Just so you know. Thank you for the pic.

 

That's like asking for the "best" color. There isn't a "best". Anywhere that's convenient & safe is as good as any other place. And the necessity of a relay is determined by the lights you add, and what circuit you add them to. If the circuit has enough capacity to handle its original load, plus the lights, with some extra for minor surges, then you don't need a relay. If the lights will push it near or over its capacity, a relay is required.

 

That makes sense, but unfortunately I am still pretty clueless. Think I am going to run the power straight off the battery, not entirely sure how to get it from anywhere else. So still not sure if the relay is necessary or not.

 

Did you read the captions in post #9? If you can't figure out the relay necessity, post ALL the specs of the lights, switch, & wiring: Watts/Amps@Volts, and wire gauge. Do you have an empty relay position in any of your relay or fuse blocks? If you're not comfortable with it, just take it to any stereo shop. They should be able to add lights for you.