[GrievousAngel]

The climate control blower motor is not running ... 2x in 2 months it did run for a short while though!

I have replaced the Climate Control Unit and checked fuse F7 and the blower 30A in-line fuse with voltmeter and they check out K at ~ 12VDC. When the blower ran last, it did not make any strange noises and pushed air strong.

Where is the blower relay box or is there one? How do I check the blower motor and regulator ... I can't locate them?

Suggestions please. MY girlfriend is freezing going to work in the CO Rockies ... Urgent please! THanks, Billy

 

[sbaert]

1st step would be to replace ALL fuses with the updated ceramic copper type.

With age, the fuses corrode internally causing erratic operation.

You can get a complete vehicle kit from joetlc.com

 

[sbaert]

The blower & regulator are located beneath the wiper transmission.

 

[i6h000]

Double ck the 30 A fuse, remove it to ensure it is intact. Many times there is a barely visible hairline crack and it splits in half when removed.

 

[Real1shepherd]

1st step would be to replace ALL fuses with the updated ceramic copper type.

With age, the fuses corrode internally causing erratic operation.

You can get a complete vehicle kit from joetlc.com

Be warned;
Ceramic fuse kit: $3.99
Shipping: $16.22

Kevin

 

[bigdogbitu]

My issue was a bad ignition switch and climate control unit. Electrical gremlins!

 

[chuckh0308]

Mine was doing the same thing last year. I ordered a new motor, but then ended up not needing it. The problem was a bad connector at the motor. The plastic had cracked and the terminal was grounding out. I replaced the terminal and wrapped everything in electrical tape and no trouble since.

 

[Clarkz71]

... moreover, you should NOT see 12v at the 30a fuse... it should read ZERO...
If you're seeing 12v, then the fuse is popped... get a new one.

... and figger out why it popped...

The fuse should have 12 volts on both ends if its good.

if you measure 12 volts with the meter leads on each end of the fuse
then it's blown and there's a short.

This fuse feeds the blower regulator red wire. Yellow is the signal from pushbutton.
Black is ground. This is the plug behind the brake booster.

 

[augapfel]

Accessing a replacing the blower motor or speed controller is not the first job you want to perform on a 124. Those components are buried pretty deep.

 

[GrievousAngel]

voltage reading at 30A fuse strip

should read 0VDC if 30A fuse is good ... if measured between ground and fuse, it would read 12VDC if GOOD. Correct? thx Billy

 

[Clarkz71]

​

should read 0VDC if 30A fuse is good ... if measured between ground and fuse, it would read 12VDC if GOOD. Correct? thx Billy

Ground lead of meter to block or battery negative, positive
lead to either side of fuse.

As far a the fuse, it could blow from being old & weak OR from a short.

Replace it and then test. Don't dwell on the 0 volts thing, just check for 12 volts on both sides.


Just check for 12 volts at red wire, ground at black wire, and signal voltage at yellow wire at this plug
on the body side, not the harness side. the harness goes to the blower regulator.

 

[GrievousAngel]

THe X64 connector (red,yel,blk wires VDC test GOOD. I do have a bad mono valve but would not affect the blower from running, correct?

So, if fuses are OK, also replaced the climate control module, and X64 VDC check OK, then what else may be defective in order to prevent blower airflow?

If the flaps are closed preventing air flow to cab, would I be able to hear the blower running? What is the best way to check vacuum/flaps and determine if the blower iss actually running?

Thanks, Billy

 

[Real1shepherd]

Fried reg, no blower. You can get down to the blower wires themselves and put 12vdc to it and if it takes off, you have a bad regulator. Otherwise, you're trying to work through the reg on your testing-don't do it this way.

You could also have worn brushes on your blower and it's not making contact....sometimes in this scenario if you slam a front door hard, it tries to run. Quit throwing random parts at it and get down to the blower itself. When the blower runs you hear it, flaps closing/opening or not.

Kevin

 

[GrievousAngel]

Thanks for advice. I will remove windshield wiper system today. BTW: My mono valve was bad, rotten rubber boot, stuck valve spool, put solenoid coil checks OK at ~ 13 ohms, so I havd a new one coming. Does the mono valve interface to blower circuitry in such a way to prevent it from running? I think not but I keep hearing .... mono valve!

Thanks, Billy

 

[dtsdig]

Be warned;
Ceramic fuse kit: $3.99
Shipping: $16.22

Kevin

Or you could but it from here and pay less than $14 shipped:

Mercedes Ceramic Fuse Set 8 16 25 Amp Set New Flosser | eBay

This is where I bought my set and the seller was great. Fast shipping and everything as it should be.

 

[Real1shepherd]

Thanks for advice. I will remove windshield wiper system today. BTW: My mono valve was bad, rotten rubber boot, stuck valve spool, put solenoid coil checks OK at ~ 13 ohms, so I havd a new one coming. Does the mono valve interface to blower circuitry in such a way to prevent it from running? I think not but I keep hearing .... mono valve!

Thanks, Billy

If your mono valve craps out depending on what position the solenoid is in, you'll either get heat all the time or little heat...or some weird combo. Your blower issue is separate and will work with or without the mono valve working.

Kevin

 

[Real1shepherd]

Or you could but it from here and pay less than $14 shipped:

Mercedes Ceramic Fuse Set 8 16 25 Amp Set New Flosser | eBay

This is where I bought my set and the seller was great. Fast shipping and everything as it should be.

Good link source...thanks for that!:thumbsup: Somehow, I wound up with the copper but plastic body....I think it was from Kent's DIY site yrs ago.

Kevin

 

[sbaert]

Good link source...thanks for that!:thumbsup: Somehow, I wound up with the copper but plastic body....I think it was from Kent's DIY site yrs ago.

Kevin

That sounds like a Kent move alright. Those fuses are probably made by Meyle or some such.

This has a eerie resemblance to the Bosch voltage regulator I bought from them, but came in a nice Meyle box made in China. When I called them about it, I was told "it's all good". Yeah right, that Meyle part went straight in the dumpster. Not worth my time or money to ship back.

Maybe I should have complained harder by telling them "If I wanted a Chinese car, I would have bought one from the Great Wall of Mart."

Perhaps URO's new slogan should be "Buy cheaply, live poorly."

 

[Real1shepherd]

That sounds like a Kent move alright. Those fuses are probably made by Meyle or some such.

This has a eerie resemblance to the Bosch voltage regulator I bought from them, but came in a nice Meyle box made in China. When I called them about it, I was told "it's all good". Yeah right, that Meyle part went straight in the dumpster. Not worth my time or money to ship back.

Maybe I should have complained harder by telling them "If I wanted a Chinese car, I would have bought one from the Great Wall of Mart."

Perhaps URO's new slogan should be "Buy cheaply, live poorly."

Yrs ago I was all gun-ho for their services & products. I still watch his videos and I'm convinced he's a decent sorta guy. But I bought 'used' accumulator spheres from him for the wagon's SLS....$150. Said to have only been on another wagon for 5K. The long & the short of it was;they're no good and "as is"...even though they had the MB Star on them. At that point I was about to invest a lot of money with them in suspension/brake products. Yeah, they were saying their stuff was "fine", but it wasn't entirely, as Kent was trying to bleed pennies with the cheap crap we've all come to know and dread. I appreciate thrifty thinking, but not on critical mechanical & suspension parts...not on these cars. So yrs ago I cut the cord....and I would caution anybody to be wary of his poser critical parts. Nice guy though.....but can you really trust an old guy that completely dyes his hair?

Kevin

 

[GrievousAngel]

BLower motor runs, good. I was able to run the blower motor via the blower wires coming from regulator! It appeared the blower motor ran full speed all the time, but ? How do I test the regulator if out of circuit? Back in circuit? I do not want to put all back together and the blower still does not run!

Suggestions on testing while putting back together? Hall Effect device test?

Thanks, Billy