What wiring will I need to add power mirrors?

[Fireball5657]

Hey all, I have a 1994 Sierra with factory power locks and windows, but of course, no power mirrors. I haven’t been able to find a set of 92-94 Blazer or Yukon door panels, I’ve only found Suburban panels and I don’t like the two extra window switches, so I’ve decided that I’ll just put the mirror switch on the gauge bezel, at my local Pull-a-Part, the Burb panels are a dime a dozen out there and the switch panels are also pretty common, so I can take the mirror switch from there.

Anyways, what wiring will I need and how much will I have to wire into my trucks harness? Could I take the wiring from a 95-98 truck instead and just use the 94 mirror switch? And does anyone have any wiring diagrams for the switch and mirror plugs and what each of the wires do?

Thanks for any help!

 

[AK49BWL]

The mirror switches are different from 92-94 and 95+, as they changed the pin-outs due to the added lighting in the later switches. You can use the 95+ switch, but you also need to get all the wiring from a 95+. The mirrors themselves are identical for all years, except 98+ some had auto-dimming and heat.

Only thing is, you'll have to split the mirror harness out of the door-to-door "crossbody" harness, as in the later trucks they ran everything together for the doors (locks, windows, and mirrors). If you get the 94 stuff, the mirror harness is already separate. You may have to build an extension harness so the left mirror wiring will reach the mirror.

As for what needs to be added to the truck, I'd say nothing... Power and ground can be supplied from the convenience center. Even the lighting if you go with a 95+ can be pulled from there.

Wiring diagram for 92-94: https://www.ak49bwl.com/other/wires/1994K1500/PowerMirrors.pdf

Wiring diagram for 95+: https://www.ak49bwl.com/other/wires/1997K1500/PowerMirrors.pdf

I have diagrams for the auto-dimming and heated mirrors as well if you want to go that route.

 

[Fireball5657]

The mirror switches are different from 92-94 and 95+, as they changed the pin-outs due to the added lighting in the later switches. You can use the 95+ switch, but you also need to get all the wiring from a 95+. The mirrors themselves are identical for all years, except 98+ some had auto-dimming and heat.

Only thing is, you'll have to split the mirror harness out of the door-to-door "crossbody" harness, as in the later trucks they ran everything together for the doors (locks, windows, and mirrors). If you get the 94 stuff, the mirror harness is already separate. You may have to build an extension harness so the left mirror wiring will reach the mirror.

As for what needs to be added to the truck, I'd say nothing... Power and ground can be supplied from the convenience center.

Wiring diagram for 92-94: https://www.ak49bwl.com/other/wires/1994K1500/PowerMirrors.pdf

Wiring diagram for 95+: https://www.ak49bwl.com/other/wires/1997K1500/PowerMirrors.pdf

I have diagrams for the auto-dimming and heated mirrors as well if you want to go that route.

Interesting, sounds like it’d be easier just to get everything from a 92-94 rather than try to get each wire from a 95-98 truck.

I’d like to do auto dimming and heated mirrors, I could rip the rear defog switch from a Burb for the heat and I have a GMT800 self-dimming mirror with compass and temp that I’ve been meaning to put in, so I could wire the auto-dimming to that, but I haven’t been able to find brand new power, heated, and self dimming mirrors for the 88-98 trucks. I know they came on Denali’s, Escalades and (maybe?) on high end 98-00 Burbs, Tahoe’s, and Yukon’s, but I haven’t been able to find any in the junkyards that haven’t already been picked, and I don’t want the big fancy tow mirrors, I don’t tow often and I don’t think they’d look good on an otherwise stock truck.

 

[AK49BWL]

Interesting, sounds like it’d be easier just to get everything from a 92-94 rather than try to get each wire from a 95-98 truck.

I’d like to do auto dimming and heated mirrors, I could rip the rear defog switch from a Burb for the heat and I have a GMT800 self-dimming mirror with compass and temp that I’ve been meaning to put in, so I could wire the auto-dimming to that, but I haven’t been able to find brand new power, heated, and self dimming mirrors for the 88-98 trucks. I know they came on Denali’s, Escalades and (maybe?) on high end 98-00 Burbs, Tahoe’s, and Yukon’s, but I haven’t been able to find any in the junkyards that haven’t already been picked, and I don’t want the big fancy tow mirrors, I don’t tow often and I don’t think they’d look good on an otherwise stock truck.

I'm in the same boat with finding mirrors.. I got a driver side off a 2000 Escalade but I'm still out a passenger side. Already have my truck wired up for the dimming and heat.

 

[Fireball5657]

I'm in the same boat with finding mirrors.. I got a driver side off a 2000 Escalade but I'm still out a passenger side. Already have my truck wired up for the dimming and heat.

Sometimes I wish I had a GMT800, all of these features that are “fancy” on GMT400s are basically standard on any non-WT GMT800. Especially the earlier 400’s that didn’t have as many options as the later trucks. I’ve been trying to retrofit so many features onto my loaded-from-the-factory 94 that would be standard on even a mid-level 99-06. Oh well lol. Thanks for the help, I guess I’ve got a trip to make either this weekend or the next.

 

[AK49BWL]

I'll take all the fancy features without all the computers to run them lol. Way too many "modules" in the GMT800+ trucks.

 

[Fireball5657]

I'll take all the fancy features without all the computers to run them lol. Way too many "modules" in the GMT800+ trucks.

Very true, I’ve got family with GMT800 trucks and they’ve had more than a few electrical issues, the GMT400’s seem to have better electronics at least. Though if I remember right, the 99-02 trucks didn’t have as much that ran through the computer, they were more like the 400’s than the 03+. I’d like to pick up a early 800, but prices are crazy right now. Oh well, i’ve got my hands full with my 94 as it is anyways lol.

 

[Erik the Awful]

I'll take all the fancy features without all the computers to run them lol. Way too many "modules" in the GMT800+ trucks.

If we're trying to add these features to our trucks, I'd prefer to have them in separate modules instead of multiplexed to one main computer that's encrypted by the manufacturer.