Another solution to A/C compressor problems at fan speeds 2 and 3

[kyle's protege5]

Switch results

I dont see any that get 12v all the time through all positions. Im gonna test out the other plug next. Will post results

 

[kyle's protege5]

Just tested every wire on the other plug. There are 2-3 wires that have power all the time, no matter what fan speed. There is no wire that gets any voltage of any kind when the fan is switched from off to any position.

 

[kyle's protege5]

OK just got done planting some trees for the wifey. I have the whole AC unit out and apart and I'm going to solder back together the connections I cut for the A/C Defrost Mod

Will post results later.


*UPDATE*

Soldered back connections on A/C control board, tested and verified they are re-connected, and still no 12v on the blue/red wire.

 

[kyle's protege5]

Im studying the wire diagram, and i just wanna make sure i understand how this works exactly.

Looks like 12v goes Battery -> Relay -> Blower
Then the ground side of blower goes to #4 switch. So in position 4 it goes straight to ground, but in 3,2,1 it goes through more and more resistors to slow its speed, correct?

There is a Blue/Yellow wire coming off of position 1, between switch and resistor pack, that goes to the circuit board to tell the A/C the fan is on in all positions.

Your device is essentially just replacing the wire from the switch/resistor to the circuit board to give it a better ground so it knows the fan is on. Because in position 1, the wire is straight to ground, but in the other positions, it goes through the resistors and is too low by the time its gets back to the #1 wire.


*update*
Found the Room fuse and it was blown.......... how the heck was my stuff working before then????


Now on the blue/red wire, it looks like it goes: Battery -> Main 100A -> BTN 40A -> Room 10A -> A/C circuit board.

It doesn't even go through the ignition switch, so it should be hot all the time...... I'm gonna find that fuse labeled "Room". You would think if it was out the whole A/C wouldn't work, who knows.
It looks like the P wire, whatever color that is, gets a switched 12v power, wouldn't that be better anyways?

 

[Fresco]

Im studying the wire diagram, and i just wanna make sure i understand how this works exactly.

Looks like 12v goes Battery -> Relay -> Blower
Then the ground side of blower goes to #4 switch. So in position 4 it goes straight to ground, but in 3,2,1 it goes through more and more resistors to slow its speed, correct?

There is a Blue/Yellow wire coming off of position 1, between switch and resistor pack, that goes to the circuit board to tell the A/C the fan is on in all positions.

Your device is essentially just replacing the wire from the switch/resistor to the circuit board to give it a better ground so it knows the fan is on. Because in position 1, the wire is straight to ground, but in the other positions, it goes through the resistors and is too low by the time its gets back to the #1 wire.


*update*
Found the Room fuse and it was blown.......... how the heck was my stuff working before then????


Now on the blue/red wire, it looks like it goes: Battery -> Main 100A -> BTN 40A -> Room 10A -> A/C circuit board.

It doesn't even go through the ignition switch, so it should be hot all the time...... I'm gonna find that fuse labeled "Room". You would think if it was out the whole A/C wouldn't work, who knows.
It looks like the P wire, whatever color that is, gets a switched 12v power, wouldn't that be better anyways?

Room Fuse???

well i kinda did my own mod and it works for me the only thing is my speed 2 and speed 1 is the same speed (speed 2) i took one of those wires with alligator clips on both sides and put one end on speed one and the other on speed 2, before this the ac wouldnt come on at speed 2, and now it does, i dont know what type of load its putting on the wire but frankly i dont care anymore, im at the point when the ac finally does take a crap im selling my p5 (shrug)

 

[kyle's protege5]

UPDATE - Fixed!!

Replaced fuse and everything works perfect!!!


THANK YOU!
THANK YOU!
THANK YOU!

When I put in the new fuse, the door chime started and the dome light came on. Those worked before, so only thing I can think of is that I accidentally touched the hot and grounds together when I was soldering on new wires.

So let this be a lesson that I never follow LOL

Unhook the battery when you do this. Will save you hours later!

 

[kyle's protege5]

Room Fuse???

well i kinda did my own mod and it works for me the only thing is my speed 2 and speed 1 is the same speed (speed 2) i took one of those wires with alligator clips on both sides and put one end on speed one and the other on speed 2, before this the ac wouldnt come on at speed 2, and now it does, i dont know what type of load its putting on the wire but frankly i dont care anymore, im at the point when the ac finally does take a crap im selling my p5 (shrug)

The Room fuse covers the radio, door chime and dome lights I found out. And just do this mod. It was really easy to make the thing, and as long as you dont pop a fuse like I did, it works perfect and all speeds work like they are supposed to.

 

[pasadena_commut]

Room Fuse???

well i kinda did my own mod and it works for me the only thing is my speed 2 and speed 1 is the same speed (speed 2) i took one of those wires with alligator clips on both sides and put one end on speed one and the other on speed 2, before this the ac wouldnt come on at speed 2, and now it does, i dont know what type of load its putting on the wire but frankly i dont care anymore, im at the point when the ac finally does take a crap im selling my p5 (shrug)

That is, in general, a very bad idea. You are now putting the current for fan speed 2 through the wire for fan speed 1, and it is not rated for it. Look at the wires - they are different gauges. At the very least feel the fan speed 1 wire while it is running like that and see how hot it gets. Possibly you can get away with this for fan speeds 2 and 1. No way it would work for speeds 4 and 1, for instance, as there is a huge difference in the wire gauges there.

The problem with your mod isn't that the AC will fail, but that the too thin wire will overheat, which could be a fire hazard.

 

[pasadena_commut]

UPDATE - Fixed!!

Good.

Unhook the battery when you do this. Will save you hours later!

Ahem, instruction step 24. I just edited the instructions to make that red, to emphasize this point.

If you tapped 12V and ground by stripping the insulation in the middle of the wire and soldering on, how did you then insulate the resulting junction? (Electrical tape always falls off eventually, especially when used in cars - which get very, very hot when parked in the sun.)

 

[pasadena_commut]

It looks like the P wire, whatever color that is, gets a switched 12v power, wouldn't that be better anyways?

P would probably work too.

 

[kyle's protege5]

Good.



Ahem, instruction step 24. I just edited the instructions to make that red, to emphasize this point.

If you tapped 12V and ground by stripping the insulation in the middle of the wire and soldering on, how did you then insulate the resulting junction? (Electrical tape always falls off eventually, especially when used in cars - which get very, very hot when parked in the sun.)

I know, I know, you should always unhook the battery. I just never do for some reason.

And I used heat shrink. If you release the wire from the plug by pushing in the little clip, you can slide the heat shrink over it. Then snap it back in the plug.

 

[radioactive_fl]

Thanks Pasadena for posting this *fix*. I just finishing following all your instructions....and BEHOLD I have A/C on fan speed 2 and 3!!! Kyle was right, this wasn't nearly as difficult as I first thought. I had tried the wire crimping fix from the other thread and it worked for about 1 month then started to act up. When the A/C began flickering on #4 I knew I needed to do something.
Another happy protege5 owner!

 

[pasadena_commut]

When the A/C began flickering on #4 I knew I needed to do something.

Glad it helped.

Mine never flickered on #4. Were there any signs of heating at the socket/plug for the #4 or ground wires? It would be good to know what the voltage is on fan wire #4 (measured at the blower resistor) to ground on your car. For comparison, here is what mine measured:

http://www.mazdas247.com/forum/show...3-A-C-PART-2&p=5647383&viewfull=1#post5647383

(Note, after this fix is applied the measurements from post 142 in that thread could change a bit as the sense line is hooked up differently and will likely pass a different amount of current. I guess for completeness I should remeasure those values.)

If your fan position #4 was flickering I'm guessing the voltage there must be .1 to .2V higher than mine was (.81V).

 

[radioactive_fl]

It would be good to know what the voltage is on fan wire #4 (measured at the blower resistor) to ground on your car.

(Note, after this fix is applied the measurements from post 142 in that thread could change a bit as the sense line is hooked up differently and will likely pass a different amount of current. I guess for completeness I should remeasure those values.)

If your fan position #4 was flickering I'm guessing the voltage there must be .1 to .2V higher than mine was (.81V).

Fan position #4 had just begun to flicker the past two weeks. Nothing looked like it had gotten hot/wires weren't brittle. I didn't measure the voltage on any of the fan wires. Next time I tear into the dash, I'll get a reading and post back (will have to wait until summer cools off).

 

[Driver_X]

Well I'm writing to say a year after this thread was created , I've completed this build and it has fixed my ac on 2 and 3. Just completed it this morning. It was really easy to build and install for around 20 bucks worth of parts.

Nice write up!

Thanks for spending the time to doc all your step.

Will try to report back in a month or two and let you guys know how it's working.

 

[P5Zac]

JUST YESTERDAY my fan speed 2 starting flickering and i noticed that the air wasnt as cold as it was on 1 or 3...after toggling between 2 and 3 a couple times it stopped and was back to normal....am i starting to show signs of this problem? if so is the solution the answer to my problems?

 

[jdwk]

Yes and yes.

 

[chubhawk]

ughh my ac light flickers on fan speed 2 to u should really make these kits and sell them

 

[Electron]

Thanks pasadena_commut! I installed this fix today and all seems to be working. I have 144,00 miles on my Protege 5 and the AC has been acting up for the past two years. I have had all the bad symptoms, compressor intermittent at all speeds and burnt wiring also. I replaced the blower motor last year because of the burnt wiring.

 

[Electron]

Two months later and the fix has been working flawlessly.