Blower motor circuit issue

Yesterday, while driving with the fan on high (setting 4) - everything was fine until I tried to reduce the fan to 3m, or 2 or 1, or even OFF. All settings cause the fan to be ON full power.
I initially thought this would be related to a blower motor resistor pack - but even when switched OFF - the fan continues to run on full power.

Anyone ever experienced this?

2004, Mazdas 3 Sport GT


Everything turns off with the ignition switch like usual, but as soon as the ignition is on - the fan is on full power regardless of the fan switch setting - including when the fan switch is in the OFF position

Thoughts?

Anyone have access to the wiring diagram for this circuit?
2004 - manual climate controls

Have you read this article? (lower section)
https://www.2carpros.com/articles/blower-fan-motor-works-on-high-speed-only
It does a good job of explaining what causes the issue and how to fix it.
Good luck.

concept said:

Have you read this article? (lower section)
https://www.2carpros.com/articles/blower-fan-motor-works-on-high-speed-only
It does a good job of explaining what causes the issue and how to fix it.
Good luck.

Click to expand...

Thank you for that.

I think my issue is somewhat different. As my blower remains on full speed even when the fan switch is in the off position...

djltoronto said:

Thank you for that.

I think my issue is somewhat different. As my blower remains on full speed even when the fan switch is in the off position...

Click to expand...

I'd say the root cause of your issue is a failed resistor with the switch having been damaged by the failing resistor.

A/C operational?

Preferio said:

I'd say the root cause of your issue is a failed resistor with the switch having been damaged by the failing resistor.

A/C operational?

Click to expand...

yes - AC fully operational - even when the fan switch is in the OFF position - I can still toggle the A/C switch and it does cycle the compressor.

I will do some testing when I get a chance.

thanks

Preferio said:

Click to expand...

Thank you sir


So, based on this - clearly the blower relay is working - providing +12v to the blower
the ground side of the motor is getting full ground, even when the switch is set to off.

It's as if the B/R wire from the fan is shorted to ground... hmm

Going over bumps, kicking the dash, wiggling the switches, and swearing loudly at the car all have no effect.

OK - issue is resolved - sorta.

Since my car has sorta high mileage - I'm really not trying to spend much money on it.



So - after reviewing the schematic posted by Preferio (thanks), I knew the issue had to be the switch.
I took some shortcuts when disassembling the dash - I did not remove the center console.





When I finally got the switch out - it looked off right away.







The switch inners - I am going to call it the swiper - had melted it's way into the body of the switch... not sure why, perhaps high resistnace in the aged switch.





So, like any cheap/thrifty individual - I decided I could probably live with the fan set on setting #2 (this is the most common setting for me) So I hard wired the switch internally to fan setting #2.
(NOTE - you will notice on the schematic that the climate control unit requires a ground signal from the switch in order to operate. I made sure to enable this as well.




So - now my fan switch rotates and feels completely normal, but the fan mode is hard wired to speed #2 - A/C works as normal

After reinstalling everything, I now had a newly burnt out bulb. I really thought I had a spare - so I removed everything only to find out I do not have a spare... crap.







Lastly - If anyone else is ever either replacing the climate control bulbs or removing the switches for any reason - and taking short cuts like me, I strongly recommend cutting 2 little notches in the plastic console to make instalation simple.





Now I have a burnt out bulb to replace




All the pics
http://imgur.com/a/s2bsA