mounting extra brake lights on 1.5” struts, NO drilling.

[LosAngeles]

Hi all. I have a weird little project on the go.

For complex reasons I won’t bore you with …….

(don’t ask why I want to do this)
;-)

... I want to mount these 3” high x 8” wide light plastic trailer brake lights on these 1.5” truck camper tie down horizontal metal struts... down below the rear of the truck camper.
but I do NOT want to drill into the struts, nor bolt into them, for obvious reasons.

I don’t own tin snips or a full shop (otherwise I could fairly easily make some custom metal brackets for the job ... that would quickly rust and be ugly)

I want to do this securely so they don’t rattle and fall off, and I’d like to keep the lights as sealed as they are, if possible.

The trailer tail light kit is less than $30 and I don’t want to have to spend a bunch of $ or time on the mounting.

One option would be to remove the front lens (on each)
Then drill small holes thru the back of the plastic box

Maybe about 2” apart... top to bottom that is. Maybe 6 holes total per box. (So 3 zip ties)

Use strong Zip Ties to secure the box to the struts (see pic)

and then use a good outdoor caulk to re -seal up the holes from the outside - to keep road crud out of the back side of the boxes.

I thought about using bolts / pipe strap / wood / etc but all that gets more ugly and time consuming I think.

These lights will simply plug into the flat trailer lights outlet on the back of the pickup, so isolated from the main trucks brake lights.

Any other simple and clever way to mount these extra brake lights? Ideally something that does not rust or rattle.

The kit comes with a license plate holder that will not work in my situation, by the way. Thanks!
https://www.amazon.com/gp/product/B004L073H8

Here is a pic
https://imgur.com/a/0iru39g

 

[PaulT]

Search for a VHB double sided waterproof foam tape at a price you find “attractive.”

Paul

 

[LosAngeles]

update - thanks Paul for the good idea...... Much appreciated.

So I like the idea of 3M VHB tape - 2 strips of 3/4” - to simply VHB tape the auxiliary brake lights to the *top* of the 1.5” strut… and the base of the brake lights are flat…. so this should work out well.

It is cold (freezing and below) where I currently am…. so I’ll have to wait a bit to install… a quick internet search indicates that VHB tape won’t adhere properly around freezing…..

I guess I could use a hair drier to first warm up the metal… but I’d be afraid that it would cool off too fast, and not bond as well as if it was warmer…..

Here is the 3/4” 3M VHB tape I’d likely buy…… sold from actual Amazon, so less likely to be a cheap fake (that 3rd party sellers sometimes sell on Amazon)

https://www.amazon.com/gp/product/B007Y7E1CU

 

[buckland]

Use your trailer lights plug if you have on. That is how I set up additional brake lights above the door..

 

[ntsqd]

Take a piece of strap metal and drill it to match the mounting holes on the rear of the lights, and bolt them on. Then place a pair of hose clamps around the square tube and the strap that you made for each light. One clamp will hold way more than the light, but it may not prevent it from rotating wonky.

 

[LosAngeles]

Update:

My question is - if I bolt into a pre-existing hole in the truck frame, (recent F-350) with a new, stainless steel bolt…. would the frames coating (anodized?) stop it from being a good ground?

see pic of my attempt at grounding (below)

I was advised to avoid drilling new holes into the truck frame… just use pre-existing holes.

so i got the trailer light kit (Blazer C6421 Trailer Light Kit) and I spoke with Blazer previously…..

and they said: I HAVE to ground the white ground wire to the truck frame.

I asked “could I just wire the white ground wire to the 4 pin flat trailer lights plug?” and they said it likely will *not* work…. and i’d need at least a 12 gauge wire … but it is better to ground to the frame.

So I wired everything up today (very simple with the kit) and plugged in… and tested the lights and they did not work at all. Never lit up. Yes the truck lights work fine, and i know that the 4 pin flat plug *is* working fine. (I tested it with something else)

I suspect the anodizing on the frame is the issue. Yes? No?

and if i have to drill a hole…. i was advised to drill into the hitch assembly, *not* the truck frame.

thanks for any guidance.

 

[ntsqd]

I use "Star" type lock washers to penetrate any dielectric coatings rather than scraping off those coatings.

They want a ground to the truck frame because most everything else on the truck uses it for a ground reference. I forget what brand and year truck you're working with, but usually the tail lights have a ground at the rear of the bed. Can use that ground for the white wire. Or later trucks have a towing connector built into the wire loom and it should have a ground wire.

FWIW I doubt that the frame is anodized as that process only applies to aluminum and titanium. The frame is likely to be steel. If it has a slightly iridescent gold look to it then it could be Alodized, but most frames that I've seen, worked on, etc. are either painted or coated in a waxy undercoating type of thick coating.