500E 1991 No Blower speed/Air

[BRABUS124]

I had it working before. put on its Windshield defroster it would after some 1-3 minutes begin to blow air in and getting higher in speed as the engine varmes up.
Now i got nothing. no Air fan speed is getting the motor to start. Max Auto Min. none of the settings work. even on Defrost mode.
If i put it in Max Varm it will give some small narrow stripes just above the vents for the windscreen. but i guess thats caused by the heat just rising up on its own or wind speed from driving.

So whats to look for.? this is the 1 temp wheel Full Automatic Climate controle system. Ive mostly worked on the dual zone Climate control systems with manual Fan speed and vents settings.
Were should i start testing and mesuring to locate the problem.

Im sure this is either the Fan it self or the Fan speed control unit. cant seems to find a snaped Fuse and ive rolled them all to grind some better electrical contact with no lock.

 

[gsxr]

There is a 30A flat strip fuse for the fan. Locate this and REMOVE the fuse to verify it is intact. If the fuse is good, next try wiggling the ignition key, a failing ignition switch can cause no voltage to the blower. Next check is pulling the blower motor out to check the brushes...

 

[BRABUS124]

Thanx.
I've got 2X 30A flat fused and checked both but only mounted. Wigled them carefully with no difrence.
So I'll take them out and check them. I've got spares as I also have a 500SEC using the same for the rear heated window.

I know from Another 124 that the regulator sits under the fan so I were afraid that's where the fault.
I've also tried to knock on the dashboard to try make an eventually bad blower brush come on again. No luck. But I guess it's not really doing it's trick that way.

But thanx for the tips. I'll try look into it.

 

[BRABUS124]

Ive located 2 flat Fuses one close to the strut tower and the other one on top of the brake booster.
Not sure witch one is what, but i measured 12 Volt on both sides og each.
No difrence changing them either.
I noticed the vacum line on top of the brake booster green with yellow stripe going into the cabin where snaped.
Could this go to the Automatic climate control? and if no vacum could cause the Fan to not run?

I wigled the key but it had no effect.

 

[gsxr]

The fuse on the strut tower is for the HVAC blower underneath the mono-wiper.

The fuse behind the brake booster is for the twin electric cooling fans ahead of the condenser/radiator.

The green/yellow vacuum pipe should go to the HVAC vacuum manifold located behind the glovebox (or, passenger airbag). The vacuum systems are completely separate from the electrical, this won't affect the blower motor.

Next up is checking for voltage at the blower regulator wiring on top of the brake booster area, then pulling the wiper and checking the fan motor / regulator...

 

[BRABUS124]

The other day i went to the car and the blower worked again. sort of strange.
But it could sounds to me like a beginning worn out blower motor or brushes inside my best guess.

 

[BRABUS124]

Replaced the fan. The old one felt hard to turn so now it works again