Relying on related info provided by "theMAN" (follows) I'm going to pursue getting a revised controller board (Mazda TSB MT000003895). I know that the electrical current through the switch is high and, on mine, there are signs of excessive temperature surrounding the common switch contact but I haven't seen anything, thank goodness, as excessive as shown on this Forum.
Info from "theMAN"
How-to: Identifying 2001-2003 Protege HVAC switch unit revision
It's safe to say that by now, every owner of the 3rd gen Protege is out of warranty. Some of us may have experienced the blinking A/C light problem at some point of time of owning the car. When the A/C light blinks, the air conditioner will start cutting out and the result is warm air.
Mazda has released a TSB years ago to address this issue, but because all of us are out of warranty, many of us don't want to spend the couple of hundred bucks for a brand new control unit and either learn to live with this defect or get a junk yard unit. Explanation of what was changed is here. (Page 2 Below)
The people who chose to get the junk yard unit in the past did not know specifically what they were looking for and thus didn't really fix the problem as they got an older unit.
The attached pic will show you what to look for to identify what control unit you have. The numbers are stamped on the side of the unit and is easy to read. If you have read the TSB, you will know by now that there are 2 different types of switches. One is for amber/red illumination and the other for green. SE/DX/LX owners will have green illumination, while the ES/P5/MP3/MSP owners will have the amber/red.
There will be some code lettering stamped on the side of the contol unit. The 4 digit alphanumeric code is the type code identifying what specifically it is. "BL8W" is for the amber/red illumination with the A/C button. "BL8F" is for the green illumination with the A/C button. If you see any other codes, it is either NOT for a 2001-2003 or not have the A/C button. There is also a standalone letter after this code and this is the most important of all as it designates the revision level of the part.
Below is a list of revision codes along with the production dates and VIN ranges (to help with online searches) of the car, so that you can know what your car has and what the junk yard car has without having to pull the dash panel out.
Green illumination (BL8F)
A = Before May 10, 2001 (VIN < 469858)
B = Between May 10, 2001 and September 16, 2002 (VIN 469858 to 643684)
C = Between September 16, 2002 and December 1, 2002 (VIN 643684 to 645019)
D = After December 1, 2002 (VIN 645019 > ) ***final revision/problem free***
Amber/red illumination (BL8W)
B = Before April 6, 2001 (VIN < 455734)
C = Between April 6, 2001 and May 10, 2001 (VIN 455734 to 469858)
D = Between May 10, 2001 and September 16, 2002 (VIN: 469858 to 643684 |||||| 2003 wagon VIN: < 127309)
E = Between September 16, 2002 and December 1, 2002 (sedan VIN: 643684 to 645019 |||||| 2003 wagon VIN: 127309 to 150990)
F = After December 1, 2002 (sedan VIN: 645019 > |||||| 2003 wagon VIN: 150990 > ) ***final revision/problem free***
ONLY the newest part will fix the problem. If you end up with an earlier part, you are wasting your money and time. The problem will come back!
Because of the extremely late production change of the part, it will be very difficult to find the updated part at the junk yard, so good luck! Remember, the last Protege's were built only until around August 2003, so there's only a limited number of Protege's with this corrected part!
740-3625
Symptoms and Conditions
Customer may experience A/C switch light going out or blinking and
warm air from vents when operating blower motor in the number 2
position for long periods of time.
Repair Procedure
Request specific fan speed during failure and note in H/L file.
If condition only occurred in the #2 fan speed, condition may be the
result of a logic error within the heater control print board.
The logic of the print board was changed by increasing the check
voltage threshold for A/C compressor engagement with the blower motor
speed set in the #2 position from 1.0V to approximately 2.0V
Date of Mass Production Change
December 02, 2002
Beginning VIN:
Protege N Protege5 JM1BJ2***3*150990
New Part Numbers:
(DX N LX Green) BL8F-61-190D
(ES Amber) BL8W-61-190F
If condition occurred in another fan speed, have dealer inspect system
connections, and confirm with customer about air flow from vents.
condition may be the result of system freeze up. if so please note in
H/L file subject line.