GMC Truck Forum banner

Finally! GMT800 style towing mirrors on GMT400.

3 reading
49K views 43 replies 26 participants last post by  88GMCtruck  
#1 ·
Finally! After years or people asking, and numerous people installing GMT800 mirrors that didn't correctly fit GMT400 trucks. Well, as some of you know, some ebay sellers started selling mirrors that apparently fit. After much debate, research, etc, I determined that the bases must be correct, and pulled the trigger on a set.

I bought the power, heated and side signal version for my truck. The goal was to put these mirrors on because the towing mirrors I currently have kinda suck. They don't extend out far enough to really see around my trailer, and they vibrate like crazy. Also, the horizontal mirror glass isn't as useful as a vertical mirror would be.

Few comparisons. My factory style CIPA towing mirrors VS the GMT800 style.
Image

Image


I also modified the mirror wiring so I can use the side LED as a marker and signal light. I added the signal wires to the 2 empty sockets in the 8-cavity plug that came with the mirrors.
Image

Image

Image


So, pull your door panel off. 95+ guys, you just have to remove the little triangle cover unlike the 88-94 trucks.
Image


And remove the foam block, and 3-10mm nuts.
Image


Bolt the new mirrors up. The actually designed these with a longer top stud, and brace that holds from the inner door structure.
Image

Image


Old mirrors
Image

Image

Image

Image


New mirrors (only one side done)
Image

Image
Image

Image
 
#28 ·
They are intended as signals. I used 4 diodes and modified the wiring so they are both markers and signals.
 
#31 ·
ahhh, do want! how much did they run you?
 
#33 ·
They were $250 shipped, but run less if you don't get heated glass or signals.
 
#36 ·
go wash that truck plz
Oh you have no idea how badly I wish I could right now. We had a few weeks of snow with freezing temps and now it has gone and melted. Now everything is covered in de-icer, dirt and gravel on the paved areas and my driveway is all mud. Really there is no point, it will look just like this after one day of driving it to town and back.
 
#37 ·
After multiple people asking how to wire the LEDs in as signal and parking lights, I FINALLY had enough time to draw a wiring diagram. If you can't figure it out from here, there isn't really much else I can do. You'll need 4 diodes for each mirror, and 12v+ from the parking lights and each respective signal 12V+

Basically, whichever circuit is de-energized acts as the ground circuit, if both are energized they have no ground and the light turns off. Both the parking and signal circuit have a floating ground when off, hence how the light can utilize this wiring to function. It's exactly how the front 194 marker light is wired.

Image
 
#38 ·
Great to know info. :waytogo:

So the power heated turnsignal mirrors, is that using the OEM mirror controls? How about a truck that doesn't have OEM mirror controls? Do they come with a switch to mount and how cheesey does it look or function???
 
#39 ·
The full power/heated version are for trucks that already had power options and use the factory switch. I made my own harness and used a S-series power mirror switch for my truck to add power and a toggle switch for heat.
 
#41 ·
Yup. I do like them on here though, and have gotten used to the visibility and power function, so I might get another set as I will tow with this truck in certain situations.
 
#42 ·
We were going to get some for my friend's truck a while back but then his mom started driving it when he got a different truck so he kinda lost interest. They look good though. I bet they will look even better on the 6.5.
 
#44 ·
I figured I'd update this, swapped the mirrors over to my "new" 99 silverado, got them wired up yesterday.

Few dusk shots of the cablights, mirror lights, and rear clearance light.
Image

Image

Image

Image

Image

Image