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Discussion Starter · #1 ·
Just installed a 2011 tow mirror onto my 02. Looks dang nice, just gotta modify a couple small things. Now, I’m looking up stuff for wiring and I can’t find my test light.
So I was wondering if you guys could help me out with getting the heated mirrors to work, running lights and blinkers?

not using adjustable mirrors fyi

Only thing I did on the truck and mirror for mod was knock off the alignment dowels on mirrors, place mirrors in the bottom two original bolt holes and drill new hole for top
 

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Discussion Starter · #2 ·
Car Vehicle Motor vehicle Automotive lighting Hood
 

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Mirror heat comes from the DEFOG circuit.
I wish I would have noticed this post sooner. I am working on the same problem with new heated mirrors. My 2002 truck did not come with heated mirrors or have a rear window defrost. Fortunately I did not cut my mirror pigtails because all the wires needed are in place. Turns out my truck has the infrastructure for heated mirrors. If you look in the fuse box under the hood you will find a relay for DEFOG plugged in on the right side. The orange wire going to the mirror comes from the 30 amp fuse just to the left of the DEFOG relay. And that orange wire is power for your mirror heat. Your mirror heat is on a timer. I suspect your mirror heater element will burn out if left on all the time. There is a timer circuit in your AC control module.

The circuit is designed so that power is supplied to the control side of the DEFOG relay when you turn your key on. The circuit is not complete until grounded. When the DEFOG button is pressed you are simply completing the circuit by giving it a ground path. This starts the timer and keeps the ground until the timer turns off. The first time you press the DEFOG button the timer stays on for 10 minutes. If you press the DEFOG button again the timer will stay on for 5 minutes. This resets when you turn the key off.

I purchased a PDF manual for my truck a while back and have located the pins that deal with the DEFOG circuit.
One diagram in the manual shows the circuit leading from the DEFOG relay to the AC control module and I was able to obtain the pin location. Unfortunately that diagram did not show anything else. After much reading I was able to find another pin with the label of DEFOG circuit and I suspect that is the pin I need to ground to start the timer going. But I am not sure where that plug is located. It should be another plug into the AC control module. I only recently got this last bit of information. I hope to get a visual on this Saturday - depends on what I can see.

The power from the control side of the DEFOG relay goes to the HVAC Control Module connector: (2 rows of 16 pins)
Pin D14 - DEFOG relay control (The only white wire listed on the D row. The upper row is the C row and has a couple of white wires.)

D1 - DK GRN
D14 - WHT if there is a wire
D13,D15,D16 are not used so D14 should be easy to locate with this info.


The other pin that is labeled DEFOG control is on the Blower Motor Control Switch Harness Connector:
(2 rows of 6 pins - top row ABCDEF -
bottom row GHJKLM (no letter i in there is correct))

Pin J - White - DEFOG relay control

A - DK GRN (Top Row)

G - LT BLU (Bottom Row)
H - GRY
J - WHT if there is a wire <-- DEFOG relay control
K - BRN
L - LT BLU
M - RED

Lets hope this works. I expect to get power on that orange wire going to the mirror if I ground pin J.
 

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Just installed a 2011 tow mirror onto my 02. Looks dang nice, just gotta modify a couple small things. Now, I’m looking up stuff for wiring and I can’t find my test light.
So I was wondering if you guys could help me out with getting the heated mirrors to work, running lights and blinkers?
cut/snip
The BCM (Body Control Module) has 3 plugs labeled Brown Blue and Purple

Blinkers - BCM connector labeled BROWN. Look under your dash. There is literally a sticker labeled BROWN.There are two rows of 12 pins on that plug.
Left Signal Wire: Brown Connector Pin B6 Likely Lt Blue wire
Right Signal Wire: Brown Connector Pin B7 Likely Dk Blue
(The pin numbers should be accurate. Use a 12volt light tester to verify)
(Check the middle two wires. That should be pin 6 and 7)

Running lights - Fuse Box under the hood.
(Running Light Power): FR PRK Fuse (Underhood Fuse Box) Fuse#51 10amp
You will need to use a Fuse Tap. When you pull the original fuse out you will put it in the lower slot on the tap. Put the new fuse for your mirrors in the upper slot.

2002 Chevy under hood fuse diagram
Rectangle Font Line Parallel Pattern
 

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Discussion Starter · #5 ·
The BCM (Body Control Module) has 3 plugs labeled Brown Blue and Purple

Blinkers - BCM connector labeled BROWN. Look under your dash. There is literally a sticker labeled BROWN.There are two rows of 12 pins on that plug.
Left Signal Wire: Brown Connector Pin B6 Likely Lt Blue wire
Right Signal Wire: Brown Connector Pin B7 Likely Dk Blue
(The pin numbers should be accurate. Use a 12volt light tester to verify)
(Check the middle two wires. That should be pin 6 and 7)

Running lights - Fuse Box under the hood.
(Running Light Power): FR PRK Fuse (Underhood Fuse Box) Fuse#51 10amp
You will need to use a Fuse Tap. When you pull the original fuse out you will put it in the lower slot on the tap. Put the new fuse for your mirrors in the upper slot.

2002 Chevy under hood fuse diagram
View attachment 1110353
Thorp, you have been delivered from the gods above!
I have been working on this for a while. Thank you for jumping in.
p.s,Thorp as in thorp wisconsin?
 

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Thorp as in thorp wisconsin?
No, Thorp is a name I made for an RPG character some 40+ years ago. For most sites I try to be anonymous with my personal info.

PS, I did not get back to my truck wiring yet. And yesterday I tried to cut my thumb off. Fortunatley its not a deep cut but it does mess my dexterity. I will try to get some testing done on that defog circuit soon. If someone beats me to the testing please chime in.

The snow here in Western Washington is making this more difficult than I was expecting.
 

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I dont have real headway to report but this is whats going on.

I took the bezel off the dash that covers the instrument cluster and
AC controls for the first time. It realy does just pull off - no
screws. You do need to put the column shifter in the lowest setting.
(Be sure your truck wont roll away) And put the steering wheel in
the lowest position. Then just pull on the bezel starting above the
steering and work the clips loose.

My HVAC control module does not have a 32 pin (2 rows of 16).
It does have the 12 pin with wire colors that matches up exacly with
the manual. Pin J in the manual labeled defog

My HVAC module does have 2 places that connectors plug in. The other
one is an 8 pin with one of the solid copper looking pins missing.
4 pins on one row and 3 pins on the other. A corner pin is missing
and that looks to be OEM. It does not look like there is supposed to
be an 8th. The connector is rectangular. I have not been able find
anything in the manual that matches.

I am hoping to resolve this without tearing my entire dashboard
apart. I still do not know what I am supposed to ground to get the
timer started in the defog system. The manual is imcomplete on this
or I am just not finding the correct passage that explains it.
Of course my HVAC control mudule may not have this timer but I don't
see why not. Seems it would be more expensive to tool up 2 different
HVAC control modules. And all the other wiring seems to be in place.
Just not a button.

I am still digging.
 

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It turns out I dont have a timer circuit in my HVAC control Module.

I missed this the first time around reading the manual.
From the manual:
"The heated mirror system is activated by depressing the rear window defogger switch, which is part of the HVAC control module. "

My control module does not have a button so I don't have a timer circuit. I wonder if I can get a module
with the button.
 
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