Blower motor

[Brisfx]

I have a question. I have replaced the whole a/c system and was wondering if I lose refrigerant and the pressure drops will that cause the blower to stop working?

[Rich]

No, it won't.

You can find the wiring details for that blower here:

http://dmctalk.org/showthread.php?40-All-Wiring-Schematics

[TTait]

The compressor will stop kicking in when the pressure goes too low...

If the blower fails on all speeds, check the wires hooking up to the bottom of it first. It's over the ties of the passenger (unless you have RHD - then I'm not sure). Then check fuses, and breakers.

[WelmoedJ]

The compressor will stop kicking in when the pressure goes too low...

If the blower fails on all speeds, check the wires hooking up to the bottom of it first. It's over the ties of the passenger (unless you have RHD - then I'm not sure). Then check fuses, and breakers.

+ check the selector diafragm. That rubber deteriorates over time and starts developing vacuum leaks or by not turning doesn't select the proper functioning of the door valves causing the heating/AC system to fail sending the selected air in the right direction.

[Brisfx]

Thanks fellas

Ok replaced a fuse now I have blower on ist setting but 2, 3 and 4 nothing. Already replaced the diaphragm, just got a new fan switch the other day.


What am I doing wrong??

[WelmoedJ]

Thanks fellas

Ok replaced a fuse now I have blower on ist setting but 2, 3 and 4 nothing. Already replaced the diaphragm, just got a new fan switch the other day.


What am I doing wrong??

Speeds 3 and 4 use a relay.
There is - inside the housing - next to the blower motor a restistor pack.
That resistor pack tends to rusting; perhaps connections are bad, corroded or gone.
If you remove the blower motor, you are able to get to the pack for inspection.

[Brisfx]

I replaced all that new during the rebuiuld a few months ago :)

[WelmoedJ]

If you did replace the resistor pack, did you put the wires back on their proper pins?
Ref: the electrical diagram for the correct colours.

[DMCMW Dave]

For as simple as it is, the blower switch is remarkably fragile. The circuit is a bit convoluted as well. The switch, and therefore speeds 1 and 2 are powered from fuse 10 through the mode switch. Speeds 3 and 4 are powered directly from the battery through a circuit breaker, but the signal to the relays is still from fuse 10. The fan speed is regulated by the resistor.

So - if fuse #10 blows you will lose all 4 speeds. If the resistor fails (usually rusting in two) you will lose speeds from the bottom up, i.e. you can lose speed 1,2,3 but still have 4. You can lose 1 and 2 but still have 3 and 4 etc.

If the mode switch fails you will lose all 4 speeds. If the breaker fails you will lose 3 AND 4. If either of the relays fail you will lose 3 OR 4. There ought to be a logic table for this one.

The fact that it runs on speed 1 tells you that the switch is getting power. When you turn it through the speeds, do you hear the relays in the back click on 3 and 4? If not they are not getting the signal from the switch. If you don't hear them click, try this:

Make yourself a fused jumper wire that you can connect to a 12V source (the lock circuit breaker is handy).

Unplug that round plug from the back of the switch. With the igntion on accessory, connnect each of the pins on the plug to 12V in turn (skip the light green, that's the source). If you hear the relays when you hit the pink/green contacts, and the blower runs at all 4 speeds as you hit the various connectors, the switch is probably bad.

If the relays are clicking and the blower does not come on, you have some other wiring issue but try this first.