Solution To Flickering Fan Speed 2 Or 3 A/C PART 2

Weborific said:

I had the same issue last year. You need to have a resistor pack replaced. It's located behind the glove box. I guess you can do it yourself but I believe you'll have to get the pack from Mazda. Don't remember the pricing...

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Do you know where I could get more information about this? I assume it would cost like 80 dollars just to have Mazda take a LOOK at the problem right? Then like 200 dollars labour to fix...=(

yeah ive had the same problem and bought a new switch from the dealer and it worked for about 2 months then same problem. I was pissed!!!! i spent $200 on it and now it dosent work again so i will try this.

Thanks(ugh)

this worked for a few weeks and now ac only works on the 1 position. and now 3 and 4 don't blow at all! I need to take it all apart again and see what happened back there, it hasn't been hot enough for me to need an a/c and the heater on 2 is thankfully sufficient.

Wow, I am surprised that all this trial and error and still no lasting permanent solution!
After reading this thread, my problem is that my A/C (green light) is on, but no proper use of my fan switch. I tried selecting different pole (1-4) and still no fan comes on..
I haven't taken a look behind the scenes yet as I just encountered this problem this morning on my way to work. Some interesting ideas though.

going to do some digging around and get back to you guys

i got a question about this, my p5 does the same thing, but what happens with mine, is if you touch the wires that go into the back of the climate control, they are SMOKING hot to the touch, they will burn your fingers in about a quarter of a second when they have been running for more then like 15 minutes, do you think this fix will rectify that problem??

cause i was gonna sell my car but i'm considering keeping it if i can fix this problem with the soldering gun i just bought lol (of course the clutch on my compressor is shot so that will need to be replaced but still....)

so i got back in there and jiggled some wires around. and i was able to get all 4 working again. the wires are extremely hot and the largest black wire (i'm assuming that the gound) seems loose. need to get back in there and replace all connectors and solder them to the posts...maybe that will fix it...

edit: oh yeah, so after i got all 4 work on AC, after a day it went back to 1 and 4 only, and now only 1. and NO heater..

deathwishkid said:

so i got back in there and jiggled some wires around. and i was able to get all 4 working again. the wires are extremely hot and the largest black wire (i'm assuming that the gound) seems loose. need to get back in there and replace all connectors and solder them to the posts...maybe that will fix it...

edit: oh yeah, so after i got all 4 work on AC, after a day it went back to 1 and 4 only, and now only 1. and NO heater..

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Check your heater cable. It may have fallen off when you were messing with the wires

@002 Protege 5 A/C switch position 2 & 3 problem

I'm looking for more help. I'm still working on the A/C Fan Swtich Pos 2 & 3 problem.

I know that replacing the Heater A/C controller with the latest Rev (Green illumination BL8F Rev D and Amber/red illumination BL8W Rev F) will correct the problem. From what I understand these models and Revs have to do with 2001 & 2002 Proteges.

My questions;

Was the problem corrected with the 2003 models?

What is the part number for a 2003 controller?

Will a 2003 controller fit exactly into a 2002 vehicle console?

Are the electrical connections exactly, electrically and physically, the same?

Are the mechanical control cable connections exactly the same?

Thank you

MJO

MJO said:

I'm looking for more help. I'm still working on the A/C Fan Swtich Pos 2 & 3 problem.

I know that replacing the Heater A/C controller with the latest Rev (Green illumination BL8F Rev D and Amber/red illumination BL8W Rev F) will correct the problem. From what I understand these models and Revs have to do with 2001 & 2002 Proteges.

My questions;

Was the problem corrected with the 2003 models?

What is the part number for a 2003 controller?

Will a 2003 controller fit exactly into a 2002 vehicle console?

Are the electrical connections exactly, electrically and physically, the same?

Are the mechanical control cable connections exactly the same?

Thank you

MJO

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The 2001-2003 heater/ac controls are all the same. Before you buy a new unit, try the soldering solution. I havent tried it yet but soon will

Just finished mine today. Everything works great. Thanks for the how to.

Ive tried everything except controller replacement and soldering the wires to the switch terminals. Im going to try to avoid the latter. I feel that the logic threshold on the controller electronics is so marginal that it may present different effects from vehicle to vehicle. So some fixes (cleaning switch, stronger springs within switch, new switch, and soldering the connector wires to the switch) may or may not provide an effective, long-term fix.
Im working with a re-cycled parts dealer in an attempt to find a controller board with the revision that will (should) correct the problem.

Thanks, MJO

the problem i found was the connectors inside the harness are so weak, they bend out of shape (even inside of the plastic clip). the problem isn't with the board ir teh switch, it's the clip and connectors not getting a good contact. by soldering them together, you eliminate the problem of weak connectors. i guess if you wanted to, you could also use stronger connectors and reinsert them into the plastic clip.

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.

ok so i figured out what the problem actually is. i went through the wire diagram and found all the signal wires and where they go. all the wires eventually run into the cotnrol computer for the ac. then after reading the TSB for this issue, i saw that the recomended fix was to replace the control computer with the newer model. the reason it needs to be replaced is because of the voltage thresholds not being properly set in the old ones. after doing a little thinking i realized that doesn't completely fix the problem, it only covers it up. the actual issue goes back to the connector. because of the bad connection, it gets enough voltage to trigger the fan, but not enough to trigger the AC. by replacing the computer it will make it so the low voltage will trigger the AC, but you still have the loose connection problem that may eventually melt the connector due to possible sparking.
so yes changing the computer out for a newer one will "fix" the problem, but you may eventually have a bigger problem to deal with.

Just completed the soldering solution. AC light is solid. Don't have a glue gun, so I just wrapped it up with duct tape. So far so good....

AC still works...

I'm going to figure this out somehow. The switch fix is fixing a completely unrelated problem.

I've scoured over the wiring diagram and the fan not blowing, yes is a problem, but is not the same.

People who's fan stopped working in 2,3 still had their A/C light on. Meaning the A/C was on, just fan was not blowing. All these crimping, soldering, whatever fixes are for that problem.

I did all the "fixes" here and they fixed the problem with the FAN a while ago. But my A/C light goes off in 2,3 and then blinks in 4 now. But my fan works fine in all positions.

This problem is a voltage problem in the control board. I've found that out on here, other forums and the dealer. I want to completely separate the blower stuff from the A/C stuff.

I'm fairly good at figuring this stuff out but would really like some others opinions. I'm going to put up the wiring diagram in my next post with some observations about it.

http://www.msprotege.com/members/kyle's%20protege5/ac%20diagram.jpg

Now to start with it, if you start at the blower relay, it looks like the 2 hots come in on top, with one side being grounded out through the switch pulling the relay in to send the power to the blower motor then the switch, then on to ground.

Does that mean the switch varies the ground for the different speeds?!?!?

The wire coming off of position "1" must trigger the A/C computer to let it turn on only when the fan is at least in position 1.

kyle's protege5 said:

People who's fan stopped working in 2,3 still had their A/C light on. Meaning the A/C was on, just fan was not blowing. All these crimping, soldering, whatever fixes are for that problem.

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Yesterday I noticed that even though the A/C light goes out on either 2 or 3, if I hold the switch exactly between 2 and 3 it comes back on. It was doing it reliably yesterday, but the stars might have just been in the proper alignment at the time. I didn't notice the fan speed change until it clicked into the other position. This doesn't make a whole lot of sense to me since if the in between position was bridging the 2 and 3 pads it should have put those two load resistors in parallel, which should have changed the fan speed up towards 3+ (assuming 4 is the smallest resistor, 1 the highest). Yet the fan speed didn't change.

Does anybody else's car do this too?

pasadena_commut said:

Yesterday I noticed that even though the A/C light goes out on either 2 or 3, if I hold the switch exactly between 2 and 3 it comes back on. It was doing it reliably yesterday, but the stars might have just been in the proper alignment at the time. I didn't notice the fan speed change until it clicked into the other position. This doesn't make a whole lot of sense to me since if the in between position was bridging the 2 and 3 pads it should have put those two load resistors in parallel, which should have changed the fan speed up towards 3+ (assuming 4 is the smallest resistor, 1 the highest). Yet the fan speed didn't change.

Does anybody else's car do this too?

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My wife's Protege sedan does this. If her lights flickers off, I move the dial slightly past 2 until the light flickers on and then move it back to 2. I'm too lazy to do the permanent fix

The fan never kicks into 3.