K2XX / 2015 style Towing Mirror Disassembly How To

[88gmctruck]

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.

*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.

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So, grab your mirror. I suggest laying a nice towel down to avoid scratching.

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.

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.

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.

Here is a closeup of the clips, and the mirror head.

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.

Backside of the convex

Now you have the mirrors removed. There are 4 screws in the corners you remove, then lift off the plastic trim

Here is the front trim and backup light removed. There is a plug on the back of the backup light.

Here you see their wonderful wiring job.......

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.

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.

 

[88gmctruck]

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.

Then remove the 4 bolts holding the post in place

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.

Once it is gone, you can pull the arms free and remove the plastic trim and pull the wiring out.

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.

 

[DieselCash]

Those are nice mirrors, I have them on my truck. Would love to paint the chrome on mine black.

 

[88gmctruck]

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

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Little bit of sanding, painting, sanding, painting, painting, sanding, some more painting and sanding then a bit of polish.

Put them all back together. I'm liking the look.

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.

Once I was done playing around, I decided it was time to take care of that pesky amber signal.....

20% black vinyl. Works SO well. And lets plenty of light through

Few photos of them on the truck, ignore how dirty it is, we haven't had much good weather here.

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

 

[btfarm]

Nice upgrade

 

[88gmctruck]

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.

 

[Will L.]

What does the backup light use as a light source, led? Maybe upgrade that led or lamp?

 

[DieselCash]

Back up lights are good for the sides, I find them helpful when it is dark with no stars or moon out.
Mine turn on with the bed lights. That might make a difference.

 

[Will L.]

Oh, so they light up the lane next to you some?

I owned a grand marquis for a while that had corner lights that came on with the turn signal- on my to do list, way down there, but on it. Might need to add more on the wish list here...

 

[DieselCash]

yes, they can only be used in park or reverse. Mine is integrated into the switch that turns on the bed lights.

 

[88gmctruck]

What does the backup light use as a light source, led? Maybe upgrade that led or lamp?

They are LED. It would be pretty complicated to upgrade them based on their design. However I do have the PN for the actual GM lights, though they are $52+/- each.

Back up lights are good for the sides, I find them helpful when it is dark with no stars or moon out.
Mine turn on with the bed lights. That might make a difference.

yes, they can only be used in park or reverse. Mine is integrated into the switch that turns on the bed lights.

Mine are wired directly to the backup lights. My regular backup lights are really bright LEDs so that is what I'm used to. The days it has been dark they just don't seem to thrown much light beside the truck is all, I need to see what they are like in the actual dark. Maybe dis-connect my other lights first.

 

[GM Guy]

so are these mirrors equipped with the custom base for the GMT400s?

If so, how is the fit and finish?

Got alot of wrecked mirrors here to attend to after the hail storm. Perfect time to upgrade!

 

[88gmctruck]

so are these mirrors equipped with the custom base for the GMT400s?

If so, how is the fit and finish?

Got alot of wrecked mirrors here to attend to after the hail storm. Perfect time to upgrade!

Yup, although they don't offer them with heat which is why i swapped parts between my existing set and this one.

They are built fine by my standards, as you'd expect for something decent from china.