Removing early style ACCII blower regulator (inside front cowl) -- anyone done it?

[Zacharias]

Okay, story so far:

I need to replace the blower regulator in my 1980 300td.

Being an ACCII system, and a wagon, it doesn't use the familiar "toaster" blower regulator on the right inner fender. Instead, it's a weird looking thing located under the wiper cowl panel, near the wiper motor. (See pics - it sits up against the outer firewall.)

Issue is, when I look down on it, it looks for all the world like the wire bundle headed to the connector should be exiting the cowl and entering the engine compartment (in the pics that is the firewall it looks like it is going through). It doesn't. It appears that it enters the passenger compartment and the plug is presumably somewhere up inside the dash, I am suspecting behind the heater box.

I have the instrument cluster and the glove compartment out, and cannot see it. Before I start pulling more stuff out, I'd like to ask some Qs.

Questions:

1. Has anyone done this job?
2. If yes, where is the actual plug location inside the dash?
3. Is there any way to work around this or make life easier?

[DeliveryValve]

I pulled one of those boxes a while back, and if I recall, it definitely part of the box. I am afraid your going to have to pull the dash to get some answers. You might have to pull the box also.

[Zacharias]

shoot

me

now

[funola]

Did you test the continuity of the resistor pack? Put an ohmmeter on the two end connections, if you get no continuity, test each coil and find which one is open and jumper it out and it may work again. If you can't fix it that way, I'd suggest not pulling the dash (too much work) and replace it with a solid state infinitely variable motor speed control.

[Zacharias]

Originally Posted by funola

Did you test the continuity of the resistor pack? Put an ohmmeter on the two end connections, if you get no continuity, test each coil and find which one is open and jumper it out and it may work again. If you can't fix it that way, I'd suggest not pulling the dash (too much work) and replace it with a solid state infinitely variable motor speed control.

Yes I followed your advice, but did not update that thread as I figured a new one would be clearer.

There are two dead coils and it appears that one of the wires into the pack burned and would need to be repaired... that was not evident at first glance.

Problem is, there is no room to work in there, even less so with my huge mitts for hands, and the harness is short - no way to pull it up out of the cowl. Seems that either route means unplugging it.

I have a replacement in hand, if I had any slack on the harness to pull out I would try to just splice it onto the existing harness.

The motor control you describe, you mean adding a manual control outside the ACC? I would prefer not, as I am getting the car ready to sell. Were it a keeper I'd be all over that.

I had also thought of switching it over to a 'toaster' pack but even that would require access to the plug... so no further ahead.

[snorider]

Is the burned wire close to the resistor pack?, If so you perhaps you might be able to use crimp and solder connectorshttp://www.nationalstandardparts.com/images/css/cssinstall.jpg

cut and strip as close to the pack as you can, get a long needle nose to crimp the conncetors then fill em with solder. I have XXL glove size so I feel your pain. This makes me feel even more excited about the prospects of repairing my 79's ACC

[Zacharias]

Originally Posted by snorider

Is the burned wire close to the resistor pack?, If so you perhaps you might be able to use crimp and solder connectorshttp://www.nationalstandardparts.com/images/css/cssinstall.jpg

cut and strip as close to the pack as you can, get a long needle nose to crimp the conncetors then fill em with solder. I have XXL glove size so I feel your pain. This makes me feel even more excited about the prospects of repairing my 79's ACC

Thanks for the advice but I have zero soldering and 4.5/10 general wiring repair skills... and this isn't a strong candidate as a teaching project.

Don't be put off by this, where your system is concerned. This is a problem that was a result of a dumbass move on my part while working with a spare blower plugged in but not bolted in.

You have a better chance of winning a major lottery than ever having to do this one.

[snorider]

Originally Posted by Zacharias

Thanks for the advice but I have zero soldering and 4.5/10 general wiring repair skills... and this isn't a strong candidate as a teaching project.

Don't be put off by this, where your system is concerned. This is a problem that was a result of a dumbass move on my part while working with a spare blower plugged in but not bolted in.

You have a better chance of winning a major lottery than ever having to do this one.

That is the cool thing about crimp and solder, The solder and flux are inside the fittinghttp://www.nationalstandardparts.com/multilink.html

so you crimp it then heat it and walla. Maybe practice with a couple outside the car first and check continuity?

I have never bought a lottery ticket so hopefully I won't win this one. Good luck man,
Michael

[cooljjay]

No way to remove it, with out removing the heater box.....do yourself a favor, find a 240d and pull all the manual climate control stuff and switch it in...

[Zacharias]

Originally Posted by cooljjay

No way to remove it, with out removing the heater box.....do yourself a favor, find a 240d and pull all the manual climate control stuff and switch it in...

Dude, I am in the rust belt. Pick and pulls have cars that are 8 years old here. Between us, Clacker and I probably own 20 percent of the w123 population within 100 miles LOL. There is no such thing as "finding" a 240d. Old Mercedes last about 72 hours when they do show up, before they look like a skeleton exposed to flesh eating fish.

In any case, I have limited time left to work on this car. And I am about to resurrect another wagon, an '84 that is missing most of its ACC components and has a damaged dash anyway (too lazy to remove the steering wheel to pull the cluster out?... no problem, just tear the dashboard binnacle out and pull it that way!). Any 240d CC gear I can come by needs to get put into that car.

I may have to take Funola's suggestion and install a manual blower control unit. I could probably float that as an 'upgrade' to a potential purchaser with a straight face, as the lack of manual override on the blower has always bugged my behind on all ACC systems... .

[Zacharias]

Originally Posted by funola

I'd suggest not pulling the dash (too much work) and replace it with a solid state infinitely variable motor speed control.

Ok, please elaborate. May seem obvious to some but I am shaky when it comes to electrics and Forrest Gump when it comes to electronics.

Thanks

[cooljjay]

Originally Posted by Zacharias

Dude, I am in the rust belt. Pick and pulls have cars that are 8 years old here. Between us, Clacker and I probably own 20 percent of the w123 population within 100 miles LOL. There is no such thing as "finding" a 240d. Old Mercedes last about 72 hours when they do show up, before they look like a skeleton exposed to flesh eating fish.

In any case, I have limited time left to work on this car. And I am about to resurrect another wagon, an '84 that is missing most of its ACC components and has a damaged dash anyway (too lazy to remove the steering wheel to pull the cluster out?... no problem, just tear the dashboard binnacle out and pull it that way!). Any 240d CC gear I can come by needs to get put into that car.

I may have to take Funola's suggestion and install a manual blower control unit. I could probably float that as an 'upgrade' to a potential purchaser with a straight face, as the lack of manual override on the blower has always bugged my behind on all ACC systems... .

Oopppsss I keep forgetting people have rust issues

Maybe keep an eye on the for sale section and finding someone parting out a 240D and have them send you everything....of course shipping is the issue...

I would think an external resistor pack would work, long as you can get to the harness to splice one in.

[Zacharias]

I happened to look at the ACC to manual climate control DIY on this site and noticed one pic that shows the total length of the harness for the blower regulator (bear in mind what I am seeing is the little stub end from the firewall grommet to the regulator, as you can see in the pic).

Are we sure the dash has to come out to reach that plug? It's certainly long enough to not be buried behind the heater box, though I realize that doesn't mean Mercedes didn't do it....

[funola]

Originally Posted by Zacharias

Ok, please elaborate. May seem obvious to some but I am shaky when it comes to electrics and Forrest Gump when it comes to electronics.

Thanks

It's custom. A potentionmeter and a power transistor variable speed control. I plan on building one for my 85. I can build you one also if you are interested.

[cooljjay]

I am to lazy well sore to walk to my 78, but I believe I seen a plug exactly like that one on the resistor under the hood on the firewall. I was wondering what it was for when I was cleaning connectors.