Is vacuuming under W126 fusebox enough?

[86560SEL]

We charged the A/C on my mothers 88 W126 today and it had been running with the A/C (fan) on high for about 20 minutes. We turned it off and I kept getting whiffs of what smelled like "hot wood" and I traced it down to the fuse box area... not in it, but around it. It dont smell electrical, it smells like someone has used a wood burning kit. I looked and natually there are alot of leaves in there and I am assuming I was smelling those heat up? I was told once that the A/C / (fan) relays were under there and get very hot. We have not used the fan in a long time (since winter when the heat was used).

I am wondering if vacuuming it alone is sufficient or should the fuse box be removed somehow to get them all? Seems like a lousy design on MBs part.

Thanks

[86560SEL]

OMG, you would not BELIEVE all of the crap (leaves, twigs, paper, etc)! that came out from under the fuse box area. There is one thing that looks like a relay at the bottom that was covered in like 2 inches of leaves/twigs. Its a wonder this car has not burned up years ago! I never dreamed there was that much debris in there.

I had been meaning to vacuum it, but kept putting it off. Apparently part of the A/C heater blower components are under there and heat up... I started the car again and felt of that relay and it was hot, so its a wonder it had not ignited when all of those leaves were under there. Just when I thought I was finished, I would find more and hear it sucking more leaves/twigs. I could not get so much directly under the fuse box itself, as that seems impossible, but I dont think there is anything actually under the fusebox itself in the way of relays? That one relay I mentioned... I was able to get my finger to drag out more crap, but the vac would not get anymore out... I am sure there is still maybe some wedged under there, but I dont see how one could get it, but I think I got as much as possible and it should be OK now. What a crappy design on an otherwise well designed MB.

This is my mothers car, she is 55 and she uses this car to take my baby nephew to therapy 3 times a weel (which is 60 miles per day round trip) and I dont want a fire to break out on her... she would have no idea what to do. Maybe the smell had been there all along, even without the A/C fan on, but we had never had the hood up with it on to smell it.

Hopefully its OK now.

[TnBob]

If your still concerned you might want to mount a battery disconnect someplace she can reach without getting under the hood.

Extinguisher might be nice too.

[86560SEL]

Thanks. Yeah, I carry an extinguisher and first aid kit in all of my cars and moms too, just to be safe.

Well I went back out and vacuumed more and there is "nary" a leaf or anything under there now, so there is really nothing to catch fire now in the way of foliage. Should be fine now. I drove the car 59 miles this evening with no fanfare (after I had vacuumed in there), but I didnt use the A/C. I am going to drive it to work all week, using the A/C (as its supposed to be in the low-mid 90s all week.

I just cannot believe all of the crap tha was down in there... dry crisp leaves (mostly from a Live Oak tree)and Loblolly pine tree needles and like I said, even some kind of paper with a coat and hat size and a small piece of newspaper! All of that was on top of a relay that I think works the A/C or fan because that only got hot when I had the A/C on. If I hadnt of noticed that smell (apparently it had just really started heating that mess up), she could have very well went on that long drive on Wednesday with the A/C and probably about 15 miles down the road (if that), I am sure it would have not been pleasant.

Word to those with a W126, if you have not cleaned out very well in around your fuse box area and well down below, you may want to get the old vacuum cleaner out with the narrow attachment and vacuum, vacuum and vacuum.

[jim16671836]

I had nearly the same thing happen to my SD. I charged up the AC while jumpering the AC Compressor and then I smelled smoke and had a small fire just below the passenger side of the Brake Booster. Their is a small part located there about 3 inches by 2 inches that I can see into where there are exposed coils that were red hot and started the leaves on fire. It is a plugin unit with pins. I don't know what it does or what it is for... Any help would be appreciated. The same kind of unit is in the 123 Euro model and it is located on the inner fender well on the passenger side. I have also seen this type of unit behind the glove box... Jim

[86560SEL]

Hmm... yeah it seems like those relay(s) are down on that side. I just took some pics, I will post and try to circle what I think is the A/C relay.

Yeah, if I hadnt of smelled it, we may have had a fire too. It was not even smoking yet, but I was just getting whiffs of hot wood (like someone had a wood burning gun). It dawned on me then that these cars have that leaf trap down in that area and I think it gets hotter when you use the heater/AC. Must be a fan relay or something or a relay for the A/C compressor.

Its a known design flaw on the W126.

[warmblood58]

Originally Posted by jim16671836

I had nearly the same thing happen to my SD. I charged up the AC while jumpering the AC Compressor and then I smelled smoke and had a small fire just below the passenger side of the Brake Booster. Their is a small part located there about 3 inches by 2 inches that I can see into where there are exposed coils that were red hot and started the leaves on fire. It is a plugin unit with pins. I don't know what it does or what it is for... Any help would be appreciated. The same kind of unit is in the 123 Euro model and it is located on the inner fender well on the passenger side. I have also seen this type of unit behind the glove box... Jim

Yep, I pull my battery once a year and use a blower to blow out all debris on both sides -HIGHLY ADVISIBLE!