HELLO AGAIN:

My vehicle has the same problem that many others have previously posted about - I am able to get both hot and cold air from the vents, but no far / blower whatsoever, no matter the adjusted fan speed (MIN / AUTO / MAX).

Earlier today I attempted to determine whether my HVAC's Blower or my HVAC's Blower Regulator is the culprit - thanks to help from detailed proceedures that other boarders have provided as insight. However, I was unable to come to a conclusion...

1st. When getting to the blower and blower regulator I noticed that my filter was extremely dirty. I noticed that one person on this board quoted $100 for the part. Is this correct? - very pricey if in fact the amount!

2nd. I had planned to bypass the regulator by connecting the "blue" wire directly to the blower, but hesitated when I touched a part of the blower with a screw driver which resulted in a large spark. The vehilce was turned off at the time. Does the Blower hold a charge to it after the car it turned off!? If so how do I "decharge" it so to evade shocking myself - what precautions should I take?

3rd. After the above incident I determined that I would hold off on the diagnosis for now - but by eye balling the electric lines that run from the vehicle to the regulator back to the blower - I was confused as to how I should simply take the regulator out of circut. I do not want to cut any of the wires. Is there a plug and play way to go about this?

A/C blower's output is low . . .

I do not have a digital camera to take a picture of my regulator and blower, but as you can see from the picture embedded in the link above - All of the power lines are covered - how am I supposed to "jump" the blue from the regulator directly to the blower???

4. If the entire blower is the culprit - is this easily removed? I could not figure out how to remove the whole piece even if i wanted to - does anyone know where the screws for such are?

THANK YOU - AND GOOD NIGHT!

Just replace it! It's bad.

The two torx screws you see hold it to the fan housing. The connector plugs in to the mating connector on the right.

When you put the new one in, make sure you use silicon grease between the bottom of the regulator's plate and fan housing. Simple job. .

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

One last question then...

When I have everything exposed (filter removed) and I trun on the car and with the air conditioning system running... am I supposed to see any gears / fans moving in the blower unit - even at a minimum speed??? Because I do not.

Before ordering a regulator I wanted to verify that it was not the blower itself. But according to your recommendation I should just go a head an replace the regulator???

Thank you.

When mine went bad, I didn't check to see if the blower was turning but to be honest, it occurred a long time ago, so the details are lost.

I could feel some 'slight' air pressure coming through the vents so it HAD to be turning a little.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

I'm going to look more into "jumping" the regulator and powering the blower directly. If it works... my order for the regulator is being placed ASAP. Thanks for your help!

The blower positive terminal is always Hot, the switching is done on the ground side of the circuit..[ referred to as a switched ground]
So, by hooking a wire to the blu wire coming out of the blower and grounding it , you have completed the blower circuit without the regulator... if the blower runs, you have a reg circuit problem.. If blower does not , check for power at red terminal of blower and if yes, blower is bad..if no power at red , check feed/fuse circuit. If blower checks out yes with jumper, then you have to check that the reg has trigger voltage from the control panel . This will be 2-8 V. at yellow wire [ depending on CP settings]. If there is V at this reg trigger , you have a bad regulator. If no trigger , you have a problem at the CP
A note:
If the reg is found to be bad , I would check the blower Amp draw wired direct to assure it is within spec [ 25A.] If it is higher, that will burn out the new regulator.. Out of spec draw is usually caused by bad/binding shaft bearings or worn brushes.
It is also possible to have a bad reg caused by a plugged air filter system, as the heat-sinz dissapation requires air flow from the system to keep it in check.. so check both of these conditions before installing a new reg. or you can burn up a new one in no time

PS
I always use a jumper with an in-line 25A fuse in the jumper just in case the blower is shorted/bound , for protection of cars harness/feed.