87 300D W124 climate control not working - PeachParts Mercedes-Benz Forum

cropduster · #1 07-22-2015, 11:53 PM

Hello all, new to forum, and new to Mercedes Benz. After doing a fair amount of research and test drives, I settled on a 87 300D turbo W124. I got the car for not much, knowing it'd need things here and there. The important stuff is working well, 308k miles but a tiny puff of smoke on start up, runs cool, has good oil pressure, runs and drives great. This 28 year old car rides better than some new cars I've been in. Anyway, to the point. These are the faults I've found and would like to correct. I've had many, many cars and worked on all of them, so I'm not afraid.

Climate control doesn't work. I can hear some vacuum actuating when pushing buttons, but the fan will not come on and there is no air flow.

Radio does not work, I tested the switched lead and it is not receiving power. The No. 1 fuse is in good order.

Could either of these issues be tied to the ignition switch? I wouldn't think so since I have power to the fuse.

Other problems:
Sunroof appears to be jammed closed.
Rear head rests are locked in the up position
Key doesn't like to work on drivers door, works much easier on the trunk

I got the car for commuting in the winter, and so I can use DSE waste oil to make my own fuel. Like I said, it runs and drives great, I'd really like to get the climate control working though, at least for some airflow. Thanks for the help! I did try and find the answers to my problems before hand.

jay_bob · #2 07-23-2015, 09:20 AM

Go to startekinfo.com or w124-zone.com
Find the link for the service manual
Chapter 83 explains it all.

Check fuse 7 first...that is the main power feed to the controls.
The blower is either Fuse 12 inside the box (early 87s) or in an external fuse holder just forward of the main fuse box.

But if you lost your main fuse 7 then you will have no action at all even on the blower since the controller can't tell the blower to start.

cropduster · #3 07-23-2015, 10:42 AM

Thanks, I'll check it out! Seems funny that both the radio and the climate control both aren't working. I think all the fuses are good, but I'll recheck. Maybe the blower has gone bad?

Maxbumpo · #4 07-23-2015, 11:54 AM

Quote:

Originally Posted by cropduster

I got the car for commuting in the winter, and so I can use DSE waste oil to make my own fuel. Like I said, it runs and drives great, I'd really like to get the climate control working though, at least for some airflow.

What is your personal time worth? I suggest you first estimate the true cost of using any fuel other than pump diesel, and decide if DSE or WVO or whatever is really an economical choice.

Example: in my situation, I calculate that my personal time outside of work hours is worth 1.5x my hourly wage. When I work overtime, that is what I get paid. Let's say that works out to $30/hour. I use about 18 gallons of fuel a week in my '87 wagon, which now costs about $2.70 per gallon, so 18 x 2.70 = 48.60, lets round up to $50 to make the math easier. If I spend more than two hours per week making my own fuel, I'm losing money (I'd have more time or more money in my pocket by working an extra two hours every week). Decide how much your time is worth, plug in your own numbers, now you've got some data to make a decision.

If your decision is not based on economic factors (saving on your fuel costs) then I urge you to really dig into the research to find out how to do it right. Doing it wrong can quickly render the car inoperable or worse destroy the engine, and I don't think you bought the car in order to destroy it. There is a section of this forum devoted to alternative fuels,

Alternative Fuels - PeachParts Mercedes ShopForum

Start there to find out what it takes with a Mercedes to have success. Way too many older Mercedes are ruined and junked because of poorly thought-out use of alternative fuels, and your car is an exceptionally rare model. Good OM603 engines are getting hard to find.

Does your state require you to file / pay extra road taxes for using an alternative fuel? Morally you have an obligation to do that, the roads weren't built for free. The rest of the drivers using pump fuel are paying the tax, so should you if your state requires it.

Phillytwotank · #5 07-23-2015, 01:27 PM

DSE is a Crock! DO NOT waste your money or time... Just my 2₵

cropduster · #6 07-23-2015, 01:42 PM

I have a co worker who's been running DSE for 8 years in his Mercedes, VW, and GMC truck. Seems to have a lot of success with them. If I don't have to buy their additive, so much the better. I do fear messing up the engine with WVO.

cropduster · #7 07-23-2015, 07:17 PM

Checked all the fuses, even the fuse link. Could it be the blower motor?