Ok so a quick background of whats happened...

Last October I took the car off the road for the winter. It got broken into (bye bye stereo hello hole in my door) and now my heater fan doesn't work.

From what I have seen for this model car (91 fc na) so far is there should be 2 relays visible on the blower unit. The "Heater Relay" which I have and clicks when I turn the blower fan on. The "Ex Hi Relay" isn't there. I called Mazda and gave them my V.I.N. and they said I only have 1 relay for my car. I've had 2 other people look at the problem but to no avail so the question is do I need the ex hi relay? I tried to bridge 1-3 on the wire harness but it did nothing, the fan works ran it off a 12v constant, I get power through the blower wire harness but the fan won't spin.

If anyone could help plz let me know much appreciated. I'm also trying to find a driver side door handle for the same car preferably red but will take others

thx

 

The online , 1991 series five wiring manual shows a ex-hi relay for that year. I don't know what else to say.

If you find the relay base, which I show in the attached jpg, then get a piece of wire and jumper the L/W to the R/Y wires in the relay base and move the lever to full right. The blower should blow, but it'll be only one speed.

My guess is the power transistor in the blower housing is shot. If you download the series five HEATING AND A/C section ,there is a test there where you see if the slider is varying the voltage to the transistor.

 

yup turns out I jumped the wrong side of the relay base last time just went out with a flashlight and checked lol. Thanks for the reply hehe I'll have my baby back on the road soon!

 

ok so I got the Ex Hi Relay from mazda and my mechanic put a new blower motor in for the hell of it. Heres my new problem...

the fan will only work on 1 speed with both relays in...and only if the blower fan is disconnected when turning the key on and then connecting it afterwards. If I move the slider to change fan speeds it dies and it won't turn back on unless I repeat the process. This is really irritating, any thoughts?

 

You might check the HEATING AND A/C series five FSM section.

I'd check the L/O wire out like the jpg attached. It seems to me you could check that output wire at the plug next to the blower housing (maybe) easier? The voltage should vary like the jpg says.

What is this one speed? FAST or slow?

I think the thing should work like my third jpg. Power from the HEATER fuse flows thru the HEATER RELAY (if it pulls in).........leaves there and goes to the Power Transistor. IF the power transistor is getting the varying volgage from the LO wire, then the power will flow from the Powr Transistor to the blower motor and it'll run.

If power is varying at the Power Transistor and the blowr motor isn't varying, the the Power Transistor is kaput imho. Probably

If the fan is blowing hard only and only when the slider is put far right, then the EX-HI is sending the Heater fuse power thru the EX-HI relay to the blower motor and the power transistor is bypassed. I didn't draw that path, but it would be from the RY wire thru that relay to the LW wire and on to the blower motor.

I really don't understand why yours is acting like it is. I'm not that good at heater/blower motor problems. I kinda recognize a blown transistor though. Sorta....in a fashion.