From: owner-diesel-benz-digest-at-digest.net (diesel-benz-digest) To: diesel-benz-digest-at-krusty-motorsports.com Subject: diesel-benz-digest V1 #272 Reply-To: diesel-benz-at-digest.net Sender: owner-diesel-benz-digest-at-digest.net Errors-To: owner-diesel-benz-digest-at-digest.net Precedence: bulk diesel-benz-digest Monday, February 7 2000 Volume 01 : Number 272 Forum for Discussion of Diesel Mercedes Benz Automobiles John Meister Digest Coordinator Contents: Climate Control Question RE: Climate Control Question Re: Climate Control Question Re: Climate Control Question Re: Climate Control Question Re: Climate Control Question RE: Climate Control Question Diesel Benz Digest Home Page: http://www.digest.net/diesel-benz/ Send submissions to diesel-benz-digest-at-digest.net Send administrative requests to diesel-benz-digest-request-at-digest.net To unsubscribe, include the word unsubscribe by itself in the body of the message, unless you are sending the request from a different address than the one that appears on the list. Include the word help in a message to stag-digest-request to get a list of other majordomo commands. ---------------------------------------------------------------------- Date: 6 Feb 2000 00:10:56 -0800 From: "Mark Fountain" Subject: Climate Control Question I have an 82 300D with a climate control problem. The heater appears to be stuck on full no matter what the setting the temperature is. It's no big deal for me but it makes my wife really uncomfortable. I was told once that this might require a $500 part. Anyone have a clue on this? Thanks, Mark Fountain Vancouver, WA ------------------------------ Date: Sun, 6 Feb 2000 04:21:14 -0500 From: "David Masinick" Subject: RE: Climate Control Question Hi Mark, There is a series of test that you need to perform on your system. The procedures are contained in the Heater/AC manual. I will "email" you through some of the tests. You may ultimately find that the pushbutton control unit is faulty, but it is a good idea to test out the system, rather than throwing parts at it. You can find rebuilt pushbutton units for $150. The first thing that you will need to do is to remove the glove box by removing the 6-8 press-in fasteners. This exposes you to the Climate control amplifier and the interior temp sensor. Although your symptoms don't seem to support this, you want to check the foam tube that connects the interior temp sensor (the one in the center of the dash)to the blower motor. This tube provides the "draw" of interior air through the sensor, so that it can sense. If the tube has disintegrated, you will need to replace it. You can test the air draw by placing a piece of tissue near the little square opening on the dash while the blower is operating. You should find the tissue is drawn to the sensor. To test the control system, you will need to disconnect the battery, and turn the ignition switch to the "on" position. You will then remove the 12-pin connector (the pins are numbered)from the CC amp (it's the one on the left, directly behind the glove box) so that you can perform some resistance tests (you'll need an ohm-meter). Try testing the following connections: Test one: In-dash temp sensor and connection lines Connect Ohm meter to sockets 1 and 6. At 15 degrees C 15.7 k-ohms +/- .5 k-ohms at 20 degrees C 10 k-ohms at 35 degrees C 6.5 k-ohms at 80 degrees C (operating temp of coolant) 1.5 k-ohms If out of range, replace sensor in dash Test two: Temp sensor for heat exchanger Connect ohm meter to sockets 6 and 9 Values the same as test one, but remember that this sensor is sensing heater core temp, so if you the engine is at operating temp, you will use the 80 degree spec. Test three: Temp wheel test Connect ohm meter to sockets 5 and 6, press center button (C) on pushbutton control unit. At 22 degrees C setting 3.15 k-ohms +/-.5 k-ohms At Min and/or Max 1.6 k-ohms If values are not within spec, connect to sockets 5 and 7 At 22 degrees C setting 3.5 k-ohms +/- 1.5 k-ohms at Min and/or Max 2 K-ohms If both tests fail, try a new/used temp wheel If temp wheel replacement fails, a new pushbutton unit is called for. The next test (mono valve) is performed with the battery connected, and the ignition switched on. Connect to sockets 1 and 8 At temp wheel setting 22 degrees, 15 ohms +/- 4 ohms At Min or Max, infinity Values outside range, replace monovalve. If that doesn't cure it, pushbutton control unit is in need of replacement. Let us know what you find. Dave Masinick Hopkinton, NH '82 300D MBCA > -----Original Message----- > From: owner-diesel-benz-at-digest.net > [mailto:owner-diesel-benz-at-digest.net]On Behalf Of Mark Fountain > Sent: Sunday, February 06, 2000 3:11 AM > To: diesel-benz list > Subject: Climate Control Question > > > I have an 82 300D with a climate control problem. The heater > appears to > be stuck on full no matter what the setting the temperature > is. It's no > big deal for me but it makes my wife really uncomfortable. > I was told once that this might require a $500 part. Anyone > have a clue > on this? > > Thanks, > Mark Fountain > Vancouver, WA > > ------------------------------ Date: Sun, 6 Feb 2000 08:15:22 -0500 From: "S.D.Byers" Subject: Re: Climate Control Question I seem to remember that when certain failures occur the climate control will default to hot air, so that at least you can defrost if nothing else. Safety critical an all that. Those clever Germans. SDB On 6 Feb 2000, Mark Fountain wrote: |I have an 82 300D with a climate control problem. The heater appears to |be stuck on full no matter what the setting the temperature is. It's no |big deal for me but it makes my wife really uncomfortable. |I was told once that this might require a $500 part. Anyone have a clue |on this? | |Thanks, |Mark Fountain |Vancouver, WA | | | ------------------------------ Date: Sun, 06 Feb 2000 08:32:41 -0800 From: john Subject: Re: Climate Control Question It could be the climate control module in the dash, or the temp sensor on the dash (the line to it could be plugged). I went through this with Fritz. I bought the controller for about $150 or so from Rusty Cullens. He's on the list but is very quiet. :) Rusty Cullens Wholesale Parts, Inc. 1-800-741-5252 He has beaten the jobber pricing I get at the Benz dealer on numerous occassions, has gotten the parts across the country post haste and been there when I needed him. I highly recommend him. FWIW< there are a few key parts on the system. The mono valve, the pushbutton control and the temp sensor. Of course there are a myriad of lesser vacuum lines to deal with. THe Impco catalog for the Benz has some useful diagrams. john (former 300D owner... (driving an 83 Jeep J10 stepside now. ;) At 12:10 AM 2/6/00 -0800, Mark Fountain wrote: >I have an 82 300D with a climate control problem. The heater appears to >be stuck on full no matter what the setting the temperature is. It's no >big deal for me but it makes my wife really uncomfortable. >I was told once that this might require a $500 part. Anyone have a clue >on this? > >Thanks, >Mark Fountain >Vancouver, WA > > - ----------------------------------------------------- john-at-wagoneers.com http://www.wagoneers.com ...don't leave life without Jesus, please! Snohomish, WA - where Jeeps don't rust, they mold... - ----------------------------------------------------- ------------------------------ Date: 6 Feb 2000 18:47:02 -0800 From: "Mark Fountain" Subject: Re: Climate Control Question Hi David, Thanks for the info on climate control. Sounds like you may have worked on this model a lot. I think the tests you describe are something I can do fairly easily and hopefully before I take off with my wife on vacation, driving down to CA next week. As an aside, there is also a problem with the center blowers not blowing air and I think that the vacuum actuator is probably defective, but on investigation have found it almost impossible to get to. Any ideas on how to approach this? Just another minor problem that wasn't real high on the priority list to fix. Also the air conditioning quit working last summer and I plan to change it over from r12 to r134 sometime before the weather gets hot again, but I don't think that would affect the heating control, would it? Thanks for taking time to help me out! Take care, Mark David Masinick wrote: > Hi Mark, > > There is a series of test that you need to perform on your system. The > procedures are contained in the Heater/AC manual. I will "email" you > through some of the tests. You may ultimately find that the pushbutton > control unit is faulty, but it is a good idea to test out the system, > rather than throwing parts at it. You can find rebuilt pushbutton units > for $150. > > The first thing that you will need to do is to remove the glove box by > removing the 6-8 press-in fasteners. This exposes you to the Climate > control amplifier and the interior temp sensor. > > Although your symptoms don't seem to support this, you want to check the > foam tube that connects the interior temp sensor (the one in the center > of the dash)to the blower motor. This tube provides the "draw" of > interior air through the sensor, so that it can sense. If the tube has > disintegrated, you will need to replace it. You can test the air draw by > placing a piece of tissue near the little square opening on the dash > while the blower is operating. You should find the tissue is drawn to > the sensor. > > To test the control system, you will need to disconnect the battery, and > turn the ignition switch to the "on" position. You will then remove the > 12-pin connector (the pins are numbered)from the CC amp (it's the one on > the left, directly behind the glove box) so that you can perform some > resistance tests (you'll need an ohm-meter). > > Try testing the following connections: > > Test one: In-dash temp sensor and connection lines > Connect Ohm meter to sockets 1 and 6. > At 15 degrees C 15.7 k-ohms +/- .5 k-ohms > at 20 degrees C 10 k-ohms > at 35 degrees C 6.5 k-ohms > at 80 degrees C (operating temp of coolant) 1.5 k-ohms > If out of range, replace sensor in dash > > Test two: Temp sensor for heat exchanger > Connect ohm meter to sockets 6 and 9 > Values the same as test one, but remember that this sensor is sensing > heater core temp, so if you the engine is at operating temp, you will > use the 80 degree spec. > > Test three: Temp wheel test > Connect ohm meter to sockets 5 and 6, press center button (C) on > pushbutton control unit. > At 22 degrees C setting 3.15 k-ohms +/-.5 k-ohms > At Min and/or Max 1.6 k-ohms > If values are not within spec, connect to sockets 5 and 7 > At 22 degrees C setting 3.5 k-ohms +/- 1.5 k-ohms > at Min and/or Max 2 K-ohms > If both tests fail, try a new/used temp wheel > If temp wheel replacement fails, a new pushbutton unit is called for. > > The next test (mono valve) is performed with the battery connected, and > the ignition switched on. > Connect to sockets 1 and 8 > At temp wheel setting 22 degrees, 15 ohms +/- 4 ohms > At Min or Max, infinity > Values outside range, replace monovalve. If that doesn't cure it, > pushbutton control unit is in need of replacement. > > Let us know what you find. > > Dave Masinick Hopkinton, NH > '82 300D MBCA > > > -----Original Message----- > > From: owner-diesel-benz-at-digest.net > > [mailto:owner-diesel-benz-at-digest.net]On Behalf Of Mark Fountain > > Sent: Sunday, February 06, 2000 3:11 AM > > To: diesel-benz list > > Subject: Climate Control Question > > > > > > I have an 82 300D with a climate control problem. The heater > > appears to > > be stuck on full no matter what the setting the temperature > > is. It's no > > big deal for me but it makes my wife really uncomfortable. > > I was told once that this might require a $500 part. Anyone > > have a clue > > on this? > > > > Thanks, > > Mark Fountain > > Vancouver, WA > > > > ------------------------------ Date: Sun, 06 Feb 2000 21:40:23 -0800 From: john Subject: Re: Climate Control Question At 06:47 PM 2/6/00 -0800, Mark Fountain wrote: >Hi David, >Also the air conditioning quit working last summer and I plan to change it >over from r12 to r134 sometime before the weather gets hot again, but I >don't think that would affect the heating control, would it? actually the heat/ac unit uses both to mix them... although when on cold it should draw air from outside... I switched Fritz over to R134. Blew at 39 degrees when done. :) Of course it was 45 degrees outside... what do you expect from a Seattle summer day anyway? ;) Just kidding, it blew 39 when it was close to 80 outside. One of the reasons I sold my 300D was because I was tired of the wide variations in temperature... Dave had provided me with lots of insight and tips, problem is I never got up the motivation to fix everything. I don't know why American cars have such easier to work on climate control systems... simple, yet amazingly effective... :) john - ----------------------------------------------------- john-at-wagoneers.com http://www.wagoneers.com ...don't leave life without Jesus, please! Snohomish, WA - where Jeeps don't rust, they mold... - ----------------------------------------------------- ------------------------------ Date: Mon, 7 Feb 2000 08:12:48 -0800 From: "David Masinick" Subject: RE: Climate Control Question Hi Mark, I'm traveling now, but I will answer some more when I get home on Wednesday. > -----Original Message----- > From: Mark Fountain [mailto:fountain-at-spiritone.com] > Sent: Sunday, February 06, 2000 6:47 PM > To: David Masinick > Cc: diesel-benz list > Subject: Re: Climate Control Question > > > Hi David, > Thanks for the info on climate control. Sounds like you may > have worked on > this model a lot. I think the tests you describe are > something I can do > fairly easily and hopefully before I take off with my wife on > vacation, > driving down to CA next week. As an aside, there is also a > problem with the > center blowers not blowing air and I think that the vacuum actuator is > probably defective, but on investigation have found it almost > impossible to > get to. Any ideas on how to approach this? Just another minor > problem that > wasn't real high on the priority list to fix. > Also the air conditioning quit working last summer and I plan > to change it > over from r12 to r134 sometime before the weather gets hot > again, but I > don't think that would affect the heating control, would it? > > Thanks for taking time to help me out! > Take care, > Mark > > David Masinick wrote: > > > Hi Mark, > > > > There is a series of test that you need to perform on your > system. The > > procedures are contained in the Heater/AC manual. I will > "email" you > > through some of the tests. You may ultimately find that > the pushbutton > > control unit is faulty, but it is a good idea to test out > the system, > > rather than throwing parts at it. You can find rebuilt > pushbutton units > > for $150. > > > > The first thing that you will need to do is to remove the > glove box by > > removing the 6-8 press-in fasteners. This exposes you to > the Climate > > control amplifier and the interior temp sensor. > > > > Although your symptoms don't seem to support this, you want > to check the > > foam tube that connects the interior temp sensor (the one > in the center > > of the dash)to the blower motor. This tube provides the "draw" of > > interior air through the sensor, so that it can sense. If > the tube has > > disintegrated, you will need to replace it. You can test > the air draw by > > placing a piece of tissue near the little square opening on the dash > > while the blower is operating. You should find the tissue > is drawn to > > the sensor. > > > > To test the control system, you will need to disconnect the > battery, and > > turn the ignition switch to the "on" position. You will > then remove the > > 12-pin connector (the pins are numbered)from the CC amp > (it's the one on > > the left, directly behind the glove box) so that you can > perform some > > resistance tests (you'll need an ohm-meter). > > > > Try testing the following connections: > > > > Test one: In-dash temp sensor and connection lines > > Connect Ohm meter to sockets 1 and 6. > > At 15 degrees C 15.7 k-ohms +/- .5 k-ohms > > at 20 degrees C 10 k-ohms > > at 35 degrees C 6.5 k-ohms > > at 80 degrees C (operating temp of coolant) 1.5 k-ohms > > If out of range, replace sensor in dash > > > > Test two: Temp sensor for heat exchanger > > Connect ohm meter to sockets 6 and 9 > > Values the same as test one, but remember that this sensor > is sensing > > heater core temp, so if you the engine is at operating > temp, you will > > use the 80 degree spec. > > > > Test three: Temp wheel test > > Connect ohm meter to sockets 5 and 6, press center button (C) on > > pushbutton control unit. > > At 22 degrees C setting 3.15 k-ohms +/-.5 k-ohms > > At Min and/or Max 1.6 k-ohms > > If values are not within spec, connect to sockets 5 and 7 > > At 22 degrees C setting 3.5 k-ohms +/- 1.5 k-ohms > > at Min and/or Max 2 K-ohms > > If both tests fail, try a new/used temp wheel > > If temp wheel replacement fails, a new pushbutton unit is > called for. > > > > The next test (mono valve) is performed with the battery > connected, and > > the ignition switched on. > > Connect to sockets 1 and 8 > > At temp wheel setting 22 degrees, 15 ohms +/- 4 ohms > > At Min or Max, infinity > > Values outside range, replace monovalve. If that doesn't cure it, > > pushbutton control unit is in need of replacement. > > > > Let us know what you find. > > > > Dave Masinick Hopkinton, NH > > '82 300D MBCA > > > > > -----Original Message----- > > > From: owner-diesel-benz-at-digest.net > > > [mailto:owner-diesel-benz-at-digest.net]On Behalf Of Mark Fountain > > > Sent: Sunday, February 06, 2000 3:11 AM > > > To: diesel-benz list > > > Subject: Climate Control Question > > > > > > > > > I have an 82 300D with a climate control problem. The heater > > > appears to > > > be stuck on full no matter what the setting the temperature > > > is. It's no > > > big deal for me but it makes my wife really uncomfortable. > > > I was told once that this might require a $500 part. Anyone > > > have a clue > > > on this? > > > > > > Thanks, > > > Mark Fountain > > > Vancouver, WA > > > > > > > ------------------------------ End of diesel-benz-digest V1 #272 *********************************