Alright, I have my father's 1987 300D turbo to be restored soon. Well obviously I havent touched the car in a long time. But ive noticed the climate control does not work properly. I only get air out of the defrost mode. I press center vents , floor or economy and the air only comes out thru the defrost and side vents. I also think the temp dial is not working eiether. Is this a electrical problem or some sort of vacume situation.

Though my '87 was not suffering from no air flow from the center vents as you are indicating you are facing, a couple of forum members gave me great advice. Vacuum is so important to these systems. Do you have a miti-vac to test some of the components? If not, get one. How about manuals? After reading the threads pertaining to the automatic climate control, I purchased the MB Service Manual Automatic Climate Control Model 124. It covers everything. So, are you yet armed with the above?
Steve

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Steve
'87 300TD - 132K - Soon 4-Sale
'84 300D Turbo - 122K - Driving
'77 VW Type II - 77K - Restored
'08 250EX Ninja
English Bulldog (Brier) - My best friend. Passed away 12/02/04 while in my arms.

If you ONLY get air out the defrost and end vents, you have a vacuum problem. Could be in the engine comapartment, you'll need to test. If the temp is wrong, that's probably electrical.

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Dave
Boise, ID
Check out my website photos, documents, and movies!

I think the temperature is working fine now. I just didnt think it was regulating temperature correctly. I think I have a huge vacumm problem. The rpm gauge does not work eiether, i think that might be a vacumm also. Where should i start?

Vacuum problems are pretty common when the car gets that old. Time to start troubleshooting.

The tach (RPM gauge) not working is NOT vacuum related, it's electrical, and not likely related to your ACC issues. However, with the tach dead, your A/C compressor won't turn on at all - it's part of a safety circuit. First check the fuses. (It's actually a good idea to replace ALL the fuses every 5 years or so - some may fall apart when you take the old ones out.) Anyway, the dead tach is most likely a bad sensor, about $50 or so last time I checked. It bolts into the engine right below the starter, and the wire goes up by the oil filter and then behind the battery. Splice the new sensor in near the battery after routing the wire up there. You can test the old one with a volt meter, but you need to cut the wires open to get the probes on there... should read increasing AC voltage (not DC!) as RPM increases. Could be a bad gauge pod (in the dash) but that's not very common.

BTW - if you're new to the world of 1987 300D's, I'd suggest reading this little buyer's guide... it has some interesting tidbits you might like to know:
http://www.w124performance.com/docs/mb/articles/124.1x3_buying_tips.txt

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Dave
Boise, ID
Check out my website photos, documents, and movies!

sorry if I missed it (this is a long post) but does the front footwell pod controll the rear footwell vent as well?

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David
1986 300E Anthracite + ECodes + MB Mileage Award

Yep.

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Dave
Boise, ID
Check out my website photos, documents, and movies!

Thank you SIR!


And another question. Do you think I can jam them open (carefully pry) from the outside -- with a dowel or something -- until I have the time and parts to fix?

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David
1986 300E Anthracite + ECodes + MB Mileage Award

GSXR, I've got an '86 300E w/only weak airflow to the front footwells, I assume they are not opening up. As far as I can tell, everything else in its ACC functions as it's supposed to. Turning the fan up higher will give noticeably more air to the side vents if they're opened, or to the windshield, if side vents are closed. I think the rear seat floor vents are getting (somewhat) more airflow than the front footwells...

I did check the center vents btw, they get strong airflow when A/C is turned to Min. But my feet are Cold driving this car w/the heat on- what's the likely culprit here?

I also wondered the same thing as David, above, if the footwell vents can just be forced open easily in the meantime, for the winter months.

In case this means anything, my fan speed pushbuttons do not always work right when first starting out in cold weather, then they "loosen up" as things warm up and function normally.

MustMakeAmends,

With the heater on max, you should get minimal airflow to the windshield - just a trickle. You should get air out the end vents and the footwell. If the defroster pod is bad, the defroster flaps won't close and you'll get weak airflow out the footwell. If the defroster is ok, then you may have a bad footwell pod that's only partially opening. (??) It's not hard to test or replace the pods, you really should pop out the glovebox and test all 7 vacuum lines. If the footwell or defroster pods are bad, they're easy to change. It's the other 4 that require dash removal.

Side note: Your 1986 model has two small round footwell pods... later cars (mid-1987 up) have a single square pod. If one is bad, you may get little to no airflow out either side. My 1986 300E had one bad pod, which caused similar problems to what you describe. I replaced it and the footwell vents work normally now with decent airflow.

I get fresh air with the system off so I must have a diaphram problem. The first step is to pull the glove box. I removed all the plastic push rivets-only broke one! Then removed the door latch on the roof of the glove box. I thought the glove box should come out. Does the light hold it in? I would hate to break the light /lens. Is there a trick to getting the box out? Thanks

Eric,

The light doesn't hold it in, but you will want to pry it loose and pull it down until you can unplug the connector then it will be out of your way.

Once all plastic fasteners are loose and the light is out of the way, you sort of have to collapse the box a little to get it to pull out.

I wish I were closer or coming to the Metroplex for some reason and I would give you a hand with it.

Hope this helps,

Yep, what Larry said. I pry the light down in front, then pull it out and disconnect the wire. With the rivets out, and metal latch unscrewed, just squeeze the middle of the box together and it will pull out. It's not terribly fragile, don't worry too much about hurting it. You can only replace the defroster pod via the glovebox opening, but you can test all 7 ports with the glovebox out of the way.

I am at the beginning stages of DIY, I think ill try to tackle the AC issue while leaving the mechanical work to someone else until I get more familiarized with the car

Where can i get this tool mentioned in the beginning of the post? [Mity Vac]

My situation for my 300E 89 203k:
Purchased car w/ 103k miles, sometime after...
- cool air / hot air and defroster working fine
- cool air working but speed switches H/L/auto no longer seemed to make a diff / hot air working / defroster working
- cool air started diminishing / hot air working / defroster working
- no cool air / hot air working / defroster working

noticed that the car windows would sometimes fog from within the car when we went to the store, etc. That was during heavy raining season, not sure if it was related to AC or different issue (no longer does that).

- car battery dead / replaced car battery
- blower no longer works (not sure if blower went out before the battery was replaced and I didnt notice or perhaps I sorted something while changing the battery).

checked metal fuse outside of fuse box (appears to be original, do not see any cracks, perhaps i should change it anyways)

In one of the pictures I saw that there seems to be a fuse in one little box next to the rest of the components behind the battery, what is that fuse for?
http://www.davebarnhart.com/mb300e/Blower/images_fullsize/Wiper1.jpg

Had the dealer test the AC when the car was serviced, they mentioned that the climate control unit was currently working but not the blower, and would need to take it apart.

Figured the first thing I need to do is replace the blower after I figure out what all (if more than one) fuses i need to check, but would like to check the pods mentioned as well, so i can start to plan out what all i may need to do.

Thanks

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89 300E - 240k +

That blue fuse is on top of the OVP relay to protect the electronics.

Replace the fan and if you go to the effort of doing pods- a good weekend. Do them all with factory parts- I'm hoping on mine that will mean another 15 years of trouble free service.

Michael

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Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E