Towing mirror install - auxilliary wire for running lights

[62Blazer]

Installing towing mirrors on my '16. The ones I bought have the option where they have running lights in them (basically the turn signal light will come on with the headlights). However you have to run a new power from the mirrors, out the doors, and into the cab of the truck. I have the wire through the wiring loom between the door and A-pillar, but can't get it fed through the opening in the A pillar to inside the cab. This is where the factory harness feeds inside the cab. I have the wire feeding through the connector at the A pillar as shown in the directions, but the issue is you can't access this location from inside the vehicle. Between the multiple layers of sheetmetal and the parking brake mechanism I can't see the wire or the opening, or get ahold of the wire from the inside to pull it through. Of course the install videos on YouTube make it look super simple, but basically skip that part (Boost Automotive and several other places have videos). The other aspects of installing the mirrors is super easy....probably less than 15 minutes per side minus that stupid wire.
Any advice?

 

[HEMIMANN]

Following.
I need to do what you're doing, bought a travel trailer for 1st time. Std side mirrors not wide enough.

 

[GRKN]

Pretty hard to follow what you're saying without pictures.

 

[jawzs2]

I used a stiffer piece of wire to run it in both my and my son's truck, taped the light wire to it and pulled it thru.

 

[62Blazer]

I used a stiffer piece of wire to run it in both my and my son's truck, taped the light wire to it and pulled it thru.

I tried a coat hanger but if you feed it through the outside of the A pillar I can't see or reach/feel the other side anywhere. It's somewhere behind the e-brake mechanism or in the body cavity.

 

[62Blazer]

Following.
I need to do what you're doing, bought a travel trailer for 1st time. Std side mirrors not wide enough.

The towing mirrors themselves are super easy to install. If the new towing mirrors have the same options as the original mirrors it's literally plug and play. I consider myself to have above average home mechanic ability and have done much harder jobs (pulling transmission, rebuilding differentials, had door panels off before replacing window motors, etc...). Watching a couple YouTube videos on the process just to see where all the screws and fasteners are without searching for them and I could swap mirrors out in under 15 minutes per side. To get the power adjust, turn signals, puddle lights, heated glass you just unplug the old mirrors and plug in the new ones. It's just the added running light option that is not available on these trucks new that requires what I am asking. To be honest I feel pretty stupid having issues with simply running that wire...........

Here is the link to boost auto parts mirror install....but it's the same for any brand you get.
https://boostautoparts.com/pages/showme

 

[jawzs2]

I tried a coat hanger but if you feed it through the outside of the A pillar I can't see or reach/feel the other side anywhere. It's somewhere behind the e-brake mechanism or in the body cavity.

Yeah - it was a PIA. A coat hanger may be a little too stiff to bend and move around. If I remember correctly, there is a small opening right behind the e-brake, I had to wiggle the wire around till I could finally see it.

 

[62Blazer]

Got it last night. Went ahead and installed the passenger side mirror and it was much easier running the wire. Just seems like there is more room and easier to get the connect loose at the A pillar, plus not nearly as much stuff on the inside area. Easy to find a way to pass the wire through to the interior. Went back to the driver's side and worked on it again. Not sure exactly why but way harder to get the A-pillar connectors out of the way (well, part of it there is only 1 connector on the passenger side but 2 on the driver's side...sure it's because of the mirror controls and all of the door locks). Wound up taking a light and moving around along the footwell/inside until I could see a little bit of light coming through on the outside A pillar....had to hold the light right at the exact spot to see it. Then was able find the very small hole to feed the wire through.
Of course was all excited and run the wires out to the fuse box, only to find out the fuse tap I bought was the wrong size.

 

[jawzs2]

Glad you got it - I tapped wire for the cab lights on the pass side dash connector. If I remember correctly, I just needed to pop off the little triangle piece on the side of the dash. Don't remember the wire colors though.