STKR

A little late, but I just read in another thread that you tighten them until the roof light housing is snug against the exterior roof. It would also help to add a little silicone as a backup to the foam gasket. I will be adding some blue Loctite to the clamp bolts as well. Question: You said you know how to locate the holes. Can you share the information you have? Thanks, Jim

I know this may be a few months late, but I found a link to the GM Upfitter site, and it has every wiriring diagram, and explanations that you could probably want. I have a 2016 2500HD LTZ, so all of my page references are for my wiring diagrams, but they should get you close. PG & Description: 46 - Center Mount High Stop Lamp (CMHSL) - - - Fed from X61A jct box, X3 connector, slot 7. 49 - DQS Cargo Lamps - - - J302 is the harness connector that goes from the X61A jct box, and splits to the left/right door jamb connectors (X500 & X600). The mirror cargo lamps are fed from X61A, connector X1, slot 17 (WH/VT wire). - - - Those two pages should give you options. If you follow the WH/VT wire back from the door jambs, you should be able to find a tie in point to isolate the mirror cargo lamps from the high mount. The diodes, relays, and wiring are up to you. LOL 292 - Power and Signal Distribution (beginning) 307 - Passenger Compartment Left Harness 405 - Master Component Locations 864 - BCM, X1 connector, goes through... (X1, X2, X3, X4, X5, X6, and X7) 877 - BCM, X7 connector. GM Upfitter: https://www.gmupfitter.com/pdflists/view/36 The 1500/2500/3500 trucks are under the Light Duty section. Drill down to the Electrical PDF (see attached image). You can download the entire PDF, but it’s around 85MB, so be prepared. Hope this helps, Jim

A big thank you goes to pgamboa for his help with the wiring on my recent upgrade. Thanks Phil! ? I just upgraded my DL3 mirrors, to the DQS tow mirrors from 1aauto (P/N: 1AMRP01786). I used Phil’s DIY wiring, and everything went great. This doesn’t mean that I didn’t have questions, but Phil was very quick to respond with help, even though I was probably interrupting his day. Sorry Phil, LOL. Like others have said; If you’re swapping mirrors, watch Phil’s very helpful YouTube videos, and get your wiring from Phil (pgamboa). I’m not sure of how bright the cargo lamp spotlights are on the GM mirrors, but the spotlights on the 1aauto mirrors are bright as hell.

Tons of great information in this thread. Thanks Phil!!! I saw the post about 1aauto parts, and their customer service. I've been trying to find a set of used DQS mirrors through eBay and using a national salvage yard search engine, but I'm not having any luck for a pair, and their cost isn't far off from the dealer cost. Sooooo... If I were to buy the set of mirrors (P/N: 1AMRP01786) from 1aauto, what additional DIY harness wiring would I need? I'm comfortable repining connectors as needed. My truck is a 2016 Chevy 2500HD LTZ that has the DL3 and A45 RPO codes on the glove box sticker, so I have all the same features as the DQS, except for the parking lamps. Jim