88GMCtruck

Woooo Boost!
Nov 4, 2015
200
47
28
37
Auburn, Wa
I recently picked up a set of 2015 style K2XX mirrors for my 98 Dually. The fine folks at eBay (aka china) have made aftermarket replacements for GMT400, GMT800 and GMT900 trucks. My truck's primary purpose is to haul an 11.5' slide in camper and a 14' enclosed trailer, so towing mirrors are a must. I currently have a set of the GMT800 style mirrors on my truck, however wanted the upgrade for the larger glass area, in glass signal and the side backup lights.

93207307-648D-4E43-929D-97F9992FE906.jpg


*Disclaimers*
- These are aftermarket mirrors. They are very similar to OEM mirrors, typically the largest difference being the power mirror head attachments are usually different.
- The plastic clips that hold the mirror glass to the motor are fragile. Be careful while trying to release them.
- The mirrors are glass. Don't break them by twisting/pulling too hard.
- I'm not going into any custom wiring information since everyone does it differently.

- And finally, i'm not responsible for any damage you do. This is a guide.

-----------------------------

So, grab your mirror. I suggest laying a nice towel down to avoid scratching.
266D97DF-D3C2-46E8-B380-A30AB9706B41.jpg


Now, you will need to push the glass in all the way in the top outer corner, and the convex all the in at the top.
113FB290-2848-4D6F-822D-3CF0EFEF0717.jpg


Hard to see, but there are 4 clips on the mirror motor head, 2 in each corner. I used a combination of my fingers and a long thin screwdriver to carefully release them.
5F66D81C-7B4A-4684-B62B-4B7F59A48D68.jpg


Once you get two sides (4 clips) they should come free with a bit of wiggling. If you have the fully loaded mirrors you will have 3 plugs to unplug, 1 for signal and 2 for heat.
2BF36983-39C6-4B2C-9A50-CDA5E5AC789C.jpg


Here is a closeup of the clips, and the mirror head.
8C3C1891-D59D-4F16-A5BE-A68A0C4CAC6B.jpg

FE9D115E-D8A7-42F6-9E83-A4AAD0964898.jpg


Now, push the convex mirror all the way in at the bottom, and do the same. It's a smaller head, with smaller clips, and much less room.
933B11C9-B868-4090-9D58-93D811FCD6DD.jpg


Backside of the convex
C507B928-D8FC-4CC1-BF70-E294C74A133F.jpg


Now you have the mirrors removed. There are 4 screws in the corners you remove, then lift off the plastic trim
EA763611-DD78-4CC9-AE1E-38546BD67662.jpg

1C2D2DB0-7B69-4863-9E5E-4A7D08FE654A.jpg


Here is the front trim and backup light removed. There is a plug on the back of the backup light.
E102440A-BA80-431D-9C3F-D424A9C3ABDE.jpg

23AAF337-7E63-4131-9023-26828C81401E.jpg


Here you see their wonderful wiring job.......
36EC6FCF-24AE-4803-A07F-8056D84E9BF6.jpg


Now, to remove the mirrors caps. You can see on both the upper and lower they are just held to the mirror in 4 places in a sort of "clip" arrangement. There was no adhesive on my mirror caps.
DCF9B153-D305-4329-BFCD-6089D2B65514.jpg

505F3C5C-0533-434F-BF48-B4529E47A7B6.jpg

A252DDE1-9FCE-48CC-A32A-75463A61F921.jpg


Now, as far as I can tell the fully loaded mirrors are always chrome. My truck is pretty much blacked out so I am going to paint them. Sanded, primed and painted.
73BA3443-440D-4D23-89E2-71FA8580705D.jpg


If you want to remove the wiring, you'll need to remove the bases and arms as well. First is to snap the mirror post cover off, I found it easiest from the back side, use a screwdriver to unclip it.
DB4A8CDD-0C3D-4C6B-9F84-080DED690216.jpg


Then remove the 4 bolts holding the post in place
B66A30DF-1D4B-49A8-B69D-CE887CC8003D.jpg


At this point you'll have to remove the mirror arms. At the end of the bottom shaft, there is a clip. The mirrors need to be about 1/2 way pulled out to remove it.
2C24FB14-7166-4C3F-8698-6A3EFEDBD567.jpg

59D60F9D-CD36-4979-B5BD-A63EC6195D58.jpg


Once it is gone, you can pull the arms free and remove the plastic trim and pull the wiring out.
905ACDB3-F638-4D0D-B79A-A0BD51DDE342.jpg

20FA11F6-1BC7-49F6-9E9C-0D800F783CDD.jpg


Beyond that, re-install is reverse of removal. You can re-assemble the mirrors without the caps and install the caps later, since paint takes time to dry.

I will mention, the aftermarket wiring of these particular mirrors has the forward amber clearance light and in glass signal wired together, which isn't the same as GM did from the factory. The amber signal was a clearance light separate from the signal. I spent the time to re-wire them to separate the lights out, so now mine are glass signal and the amber is a clearance light and signal. I used diodes internally, since everyone wires their stuff differently I'm not going to go into it at this point.

I will update the thread with more pictures once I have the caps on, and once they are on the truck.
 

SuperchargedSS

Active Member
Jan 24, 2011
316
23
28
Would like to add that on the OEM (not replica) mirrors, the top mirror comes off in a different manner. Might want to note this for those who don't want to accidentally break their OEM units.
 

88GMCtruck

Woooo Boost!
Nov 4, 2015
200
47
28
37
Auburn, Wa
For those who are thinking of getting GMT800 99-02 mirrors like i did, there is one little snag I did not know about. The polarity of the mirrors between GMT400 and GMT800 trucks is reversed left and right in the switch, and because of the way the mirror motors and switches are built there is no good/easy way to overcome this, swapping the wires just moves the polarity swap to the up/down function instead of the left/right. Just something I have to live with unfortunately

-----------------------------

Little bit of sanding, painting, sanding, painting, painting, sanding, some more painting and sanding then a bit of polish.
3BFFABBC-C432-45BC-8990-80FF7942C709.jpg


Put them all back together. I'm liking the look.
628C3CC9-01EC-4FA8-A684-53FCCE8EB8B4.jpg


I also snagged a few comparison shots of the new VS old mirror. Both the upper and lower glass is larger by a decent amount. The lower convex is WAY wider of an angle which should be a huge advantage. The mirrors don't stick out any farther while they are in, though when pulled out they actually extend less than the previous style mirror.
843E1BBE-F22A-4240-A52A-B8E59253EBBF.jpg

84457A0C-3FB5-4406-8077-C9BCA394DD34_1.jpg

AF4D1D61-233E-4B12-962F-5A746D8DAC2F.jpg


Once I was done playing around, I decided it was time to take care of that pesky amber signal.....
06DABD9E-C393-4903-99F8-A755DE436CA4.jpg


20% black vinyl. Works SO well. And lets plenty of light through
3B11A6A9-6ECD-409D-BA53-2AF656A7CBEC_1.jpg


Few photos of them on the truck, ignore how dirty it is, we haven't had much good weather here.
42FE1DF1-3778-4A9B-961A-8490DCBACC76.jpg

3310C74E-060E-426A-B1E2-258F4C500130.jpg

5A486CD8-C7BF-4C54-8746-BE8C6312C5D1.jpg


I still haven't finished wiring them up, hopefully will get them done tonight.
 

88GMCtruck

Woooo Boost!
Nov 4, 2015
200
47
28
37
Auburn, Wa
Would like to add that on the OEM (not replica) mirrors, the top mirror comes off in a different manner. Might want to note this for those who don't want to accidentally break their OEM units.
Sorry I missed this, it was the first disclaimer in the post.

--------------------------

Got everything all wired up and working. Here are my observations:

- The Clearnace lights and Glass Signals are nice and bright and useful.
- They seem to vibrate less than the previous style.
- The Convex mirror is WAY more wide angled. I don't think a blind spot exists anymore.
- The backup lights don't really do anything useful it seems. :(