Another blower motor switch issue thread

[pbeach]

Hi guys.

Apologies in advance for adding yet another blower motor thread — unavoidable. I've digested related blower motor threads here in the forum + watched a bunch of YouTube vids:

(I've changed out the blower motor and blower motor resistor twice before — last one was a year ago, so familiar territory — though both times, the issue was that the motor only worked on the high setting)

ISSUE: the blower motor doesn't work on ANY of the 4 speed settings on the blower switch.

1. the 10amp fuse in the #8 slot behind the glove compartment is a new Bussmann.

2. I removed the A/C & Heater Control panel — everything looks pristine with the switches and connections — no melting of the common ground.

3. I changed out the blower motor switch on the panel with a second one I had from my spare parts panel. Nothing. (maybe the 2nd switch is bad? Doubtful)

4. Tried hitting the bottom of the blower motor with my hand, thinking it might be stuck with leaves. Nothing.

Q: If the blower motor resistor is bad, can that cause the blower motor switch to not work on any of the settings?

Thoughts? Many thanks in advance gentlemen.

~ Peter

>>> UPDATE.1:

1. installed a new A/C & Heater Control panel — still, the blower motor doesn't work on ANY of the 4 speed settings on the blower switch.

— there's power to the fuses and specifically #8
— there's power to the blower motor (the blower motor — VDO / CONTINENTAL — was replaced less than a year ago, along with the resistor)

Next up: replace the resistor.

Thoughts? Am I missing something?

 

[JKP]

The resistor has multiple resistors to control fan speed. High is just straight through, no resistor, IIRC. Doubtful every path is blown.

The main control switch is what actually turns on the pwr to the fan, the speed switch just selects the resistor path.

With a new motor and resistor, if you only had high, that sounds like a bad fan speed switch.

But it could also be the main control switch since you swapped out the fan speed switch.

I just replaced the entire control panel when my speed switch started acting up.

 

[Mac57]

You confirmed you have power going to the blower motor. If it doesn't operate then I'd suggest the motor itself is the problem.

 

[CharlesHS]

Hope this schematic assists you in troubleshooting your problem.

 

[Edgar Marton]

I would like to install an extra switch for the blower motor - I think this has to be done somehow via the relay. Is there a way to switch off the blower motor in general and switch it on again when required - the control panel for the air conditioning no longer has any function and the switch for flaps positions is fixed and nőt in zéró position. I have installed a new heating system so that the flaps can no longer be moved and the rotary position switch for the flaps can Not moved too.
All I want to do is electrically simulate the zero position of the flap selector switch in a different way as if the flap selector switch is set to zero off and the heater motor is not running. Any ideas?

 

[ColoJeep]

I would like to install an extra switch for the blower motor - I think this has to be done somehow via the relay. Is there a way to switch off the blower motor in general and switch it on again when required - the control panel for the air conditioning no longer has any function and the switch for flaps positions is fixed and nőt in zéró position. I have installed a new heating system so that the flaps can no longer be moved and the rotary position switch for the flaps can Not moved too.
All I want to do is electrically simulate the zero position of the flap selector switch in a different way as if the flap selector switch is set to zero off and the heater motor is not running. Any ideas?

Edgar , Look at the post above with the wiring diagram. look at the far right side , install a switch anywhere in the Z1 20 BK wire. when the switch is open the blower relay will not engage ( turn on ) the blower motor. I hope this helps.

 

[Edgar Marton]

Edgar , Look at the post above with the wiring diagram. look at the far right side , install a switch anywhere in the Z1 20 BK wire. when the switch is open the blower relay will not engage ( turn on ) the blower motor. I hope this helps.

Thanks for the quick reply. Do I need a 40 amp switch for this or is a normal toggle switch sufficient? For example this one:

And which color means BK?
Thanks and all the Best from Hungary

 

[hear]

Thanks for the quick reply. Do I need a 40 amp switch for this or is a normal toggle switch sufficient? For example this one:
View attachment 613103

And which color means BK?
Thanks and all the Best from Hungary

BK is black. I would use a switch rated at least as high as the fuse size for that circuit.

 

[ColoJeep]

Thanks for the quick reply. Do I need a 40 amp switch for this or is a normal toggle switch sufficient? For example this one:
View attachment 613103

And which color means BK?
Thanks and all the Best from Hungary

BK= Black . The Best part about this fix is you are only controlling the coil of the blower relay , there is VERY little amp draw a normal toggle is enough to safely do what you want. Let us know how this works after you are finished.