Re: [MBZ] Air Conditioning Mystery
Don, my experience is with W123 chassis cars, but I think the climate control system is similar to your 380. My '82s have the climate control with monovalve. Assuming your pushbutton panel directs air where it's supposed to go, I'd start looking for cracked solder joints. Reflow all the solder connections in the pushbutton unit, blower switch and temp control wheel. An illuminated gooseneck magnifier makes it a snap if your eyes are getting a little dim like mine. If reflowing the joints in the panel doesn't make a difference, I'd pull the blower relay and climate control relay box. In the W123 they're behind the glovebox, but I have no clue on the W126. Wherever. Open 'em up and reflow them too. My experience is with my '82 300cd, which blew icy cold on hot days but would suddenly stop blowing altogether (this is with the center button depressed) at any speed. After a couple minutes it resumed with fan speed at full-blast, like it was catching up. How about trying this to indicate whether your CC problem is electrical rather than vacuum related: I could get the blower back into action in my car manually by punching the No. 2 button, the one to the immediate right of the defrost button that sends air to the footwell. I reflowed the pushbutton unit first to no avail, but the resoldering in the blower/cc relay boxes did the trick! I wish I could tell you which one made the difference, but once I cracked out my 25a soldering iron, I was a raging bull. If it looked like a lead/tin alloy, I was melting it. Russ Maki Ixonia, Wis. Don Teresa Merriman wrote: Gracias for the input. For awhile if I turned on the air with blower on before I started the car it would run for awhile, Don´t ya just love it when ya don´t get all the information on the first go around, dahhh, sorry. Should I still let out some freon? Don On 6/21/05, Trampas [EMAIL PROTECTED] wrote: You have too much Freon in the system. When you stop the high side pressure gets higher due to low air flow, this will turn on the Aux fan in front of car. If pressure continues to increase it will turn off the AC compressor. If you remove a small amount of Freon this problem will go away. Regards, Trampas -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rich Thomas Sent: Monday, June 20, 2005 11:50 PM To: Don Teresa Merriman; Mercedes mailing list Subject: Re: [MBZ] Air Conditioning Mystery Is the condenser condensing at low speeds? Is there a cutout on the blower if things are not as they are supposed to be in the system? I went through the whole circuit diagrams and schematic for the A/C system a couple of years ago, and forgot most of it, but I do remember there are a bunch of switches and such that monitor temps and pressures, and turn stuff on and off when those things change. Might be worth studying the diagrams and seeing what is connected to the blower to shut it off? That isn't much help, but in studying the schematics I got a good understanding of how it works or not, as the case may be. --R Don Teresa Merriman wrote: Hola amigos I have a air conditioning mystery with my 1982 380SEL. Replaced the condenser and compressor, both only lasted 472,000 miles. Interesting that the Delco Morraine OE unit only lasted 472,000 miles, same unit as used on new GM products in the 80´s. The blower motor works at all three speeds, the button for the automatic temp control system works. The temp control wheel works OK. The problem is when the air flow is slow or non exitant. Driving on the open road with a constant air flow the air conditioning works all day long, the problem is when the air flow is cut down, stopped, in traffic, or when you really need the air. The engine temp is consistent at 80C, never a under the hood temp too high, only when stopped or low air flow. When the temp goes up the electric fan kicks in at the appropriate temp. The mystery is why only does the blower quit working when the air flow is low or non existent? Gracias amigos -- Don Teresa Merriman Market Place Mexico Vacation Rentals Property Administration ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com http://www.buymbparts.com For repairs see www.oldworldauto.com http://www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com http://www.buymbparts.com For repairs see www.oldworldauto.com http://www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com http
Re: [MBZ] Air Conditioning Mystery
Voltage drop?? bill Don Teresa Merriman [EMAIL PROTECTED] To il.com Mercedes mailing list Sent by: [EMAIL PROTECTED] Mercedes-bounces@ cc striplin.net Subject [MBZ] Air Conditioning Mystery 06/20/2005 08:18 PM Please respond to Don Teresa Merriman [EMAIL PROTECTED] il.com; Please respond to Mercedes mailing list [EMAIL PROTECTED] n.net Hola amigos I have a air conditioning mystery with my 1982 380SEL. Replaced the condenser and compressor, both only lasted 472,000 miles. Interesting that the Delco Morraine OE unit only lasted 472,000 miles, same unit as used on new GM products in the 80´s. The blower motor works at all three speeds, the button for the automatic temp control system works. The temp control wheel works OK. The problem is when the air flow is slow or non exitant. Driving on the open road with a constant air flow the air conditioning works all day long, the problem is when the air flow is cut down, stopped, in traffic, or when you really need the air. The engine temp is consistent at 80C, never a under the hood temp too high, only when stopped or low air flow. When the temp goes up the electric fan kicks in at the appropriate temp. The mystery is why only does the blower quit working when the air flow is low or non existent? Gracias amigos -- Don Teresa Merriman Market Place Mexico Vacation Rentals Property Administration ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com For repairs see www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net
Re: [MBZ] Air Conditioning Mystery
Is the condenser condensing at low speeds? Is there a cutout on the blower if things are not as they are supposed to be in the system? I went through the whole circuit diagrams and schematic for the A/C system a couple of years ago, and forgot most of it, but I do remember there are a bunch of switches and such that monitor temps and pressures, and turn stuff on and off when those things change. Might be worth studying the diagrams and seeing what is connected to the blower to shut it off? That isn't much help, but in studying the schematics I got a good understanding of how it works or not, as the case may be. --R Don Teresa Merriman wrote: Hola amigos I have a air conditioning mystery with my 1982 380SEL. Replaced the condenser and compressor, both only lasted 472,000 miles. Interesting that the Delco Morraine OE unit only lasted 472,000 miles, same unit as used on new GM products in the 80´s. The blower motor works at all three speeds, the button for the automatic temp control system works. The temp control wheel works OK. The problem is when the air flow is slow or non exitant. Driving on the open road with a constant air flow the air conditioning works all day long, the problem is when the air flow is cut down, stopped, in traffic, or when you really need the air. The engine temp is consistent at 80C, never a under the hood temp too high, only when stopped or low air flow. When the temp goes up the electric fan kicks in at the appropriate temp. The mystery is why only does the blower quit working when the air flow is low or non existent? Gracias amigos -- Don Teresa Merriman Market Place Mexico Vacation Rentals Property Administration ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com For repairs see www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net
RE: [MBZ] Air Conditioning Mystery
You have too much Freon in the system. When you stop the high side pressure gets higher due to low air flow, this will turn on the Aux fan in front of car. If pressure continues to increase it will turn off the AC compressor. If you remove a small amount of Freon this problem will go away. Regards, Trampas -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rich Thomas Sent: Monday, June 20, 2005 11:50 PM To: Don Teresa Merriman; Mercedes mailing list Subject: Re: [MBZ] Air Conditioning Mystery Is the condenser condensing at low speeds? Is there a cutout on the blower if things are not as they are supposed to be in the system? I went through the whole circuit diagrams and schematic for the A/C system a couple of years ago, and forgot most of it, but I do remember there are a bunch of switches and such that monitor temps and pressures, and turn stuff on and off when those things change. Might be worth studying the diagrams and seeing what is connected to the blower to shut it off? That isn't much help, but in studying the schematics I got a good understanding of how it works or not, as the case may be. --R Don Teresa Merriman wrote: Hola amigos I have a air conditioning mystery with my 1982 380SEL. Replaced the condenser and compressor, both only lasted 472,000 miles. Interesting that the Delco Morraine OE unit only lasted 472,000 miles, same unit as used on new GM products in the 80´s. The blower motor works at all three speeds, the button for the automatic temp control system works. The temp control wheel works OK. The problem is when the air flow is slow or non exitant. Driving on the open road with a constant air flow the air conditioning works all day long, the problem is when the air flow is cut down, stopped, in traffic, or when you really need the air. The engine temp is consistent at 80C, never a under the hood temp too high, only when stopped or low air flow. When the temp goes up the electric fan kicks in at the appropriate temp. The mystery is why only does the blower quit working when the air flow is low or non existent? Gracias amigos -- Don Teresa Merriman Market Place Mexico Vacation Rentals Property Administration ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com For repairs see www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com For repairs see www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net
Re: [MBZ] Air Conditioning Mystery
Gracias for the input. For awhile if I turned on the air with blower on before I started the car it would run for awhile, Don´t ya just love it when ya don´t get all the information on the first go around, dahhh, sorry. Should I still let out some freon? Don On 6/21/05, Trampas [EMAIL PROTECTED] wrote: You have too much Freon in the system. When you stop the high side pressure gets higher due to low air flow, this will turn on the Aux fan in front of car. If pressure continues to increase it will turn off the AC compressor. If you remove a small amount of Freon this problem will go away. Regards, Trampas -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rich Thomas Sent: Monday, June 20, 2005 11:50 PM To: Don Teresa Merriman; Mercedes mailing list Subject: Re: [MBZ] Air Conditioning Mystery Is the condenser condensing at low speeds? Is there a cutout on the blower if things are not as they are supposed to be in the system? I went through the whole circuit diagrams and schematic for the A/C system a couple of years ago, and forgot most of it, but I do remember there are a bunch of switches and such that monitor temps and pressures, and turn stuff on and off when those things change. Might be worth studying the diagrams and seeing what is connected to the blower to shut it off? That isn't much help, but in studying the schematics I got a good understanding of how it works or not, as the case may be. --R Don Teresa Merriman wrote: Hola amigos I have a air conditioning mystery with my 1982 380SEL. Replaced the condenser and compressor, both only lasted 472,000 miles. Interesting that the Delco Morraine OE unit only lasted 472,000 miles, same unit as used on new GM products in the 80´s. The blower motor works at all three speeds, the button for the automatic temp control system works. The temp control wheel works OK. The problem is when the air flow is slow or non exitant. Driving on the open road with a constant air flow the air conditioning works all day long, the problem is when the air flow is cut down, stopped, in traffic, or when you really need the air. The engine temp is consistent at 80C, never a under the hood temp too high, only when stopped or low air flow. When the temp goes up the electric fan kicks in at the appropriate temp. The mystery is why only does the blower quit working when the air flow is low or non existent? Gracias amigos -- Don Teresa Merriman Market Place Mexico Vacation Rentals Property Administration ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com http://www.buymbparts.com For repairs see www.oldworldauto.com http://www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com http://www.buymbparts.com For repairs see www.oldworldauto.com http://www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com http://www.buymbparts.com For repairs see www.oldworldauto.com http://www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net -- Don Teresa Merriman Market Place Mexico Vacation Rentals Property Administration
Re: [MBZ] Air Conditioning Mystery
Don Teresa Merriman wrote: Gracias for the input. For awhile if I turned on the air with blower on before I started the car it would run for awhile, Don´t ya just love it when ya don´t get all the information on the first go around, dahhh, sorry. Should I still let out some freon? What you report further suggests something related to BLOWER control and NOT to compressaor operation or cooling. I don't see any way that too much freon could lower the blower speed. I believe that blower speed WILL change as cabin temperature (as measured by the cabin temp sensor) approaches the temp set on the temp wheel if the control is in the auto position. If the temp sensor doesn't have sufficient air drawn across it (if the venturi tube from the lower housing to the temp sensor) - perhaps because the foam tube has disintegrated, fan speed and/or temp control MAY become erratic. Marshall -- Marshall Booth (who doesn't respond to unsigned questions) der Dieseling Doktor [EMAIL PROTECTED] '87 300TD 181Kmi,'87 190D 2.5 199Kmi, '84 190D 2.2 227Kmi, '85 190D 2.0 159Kmi, '87 190D 2.5 turbo 234kmi Diesel Technical Advisor MBCA, member GWSection http://www.dhc.net/~pmhack/mercedes/mbooth1.htm
Re: [MBZ] Air Conditioning Mystery
Just wondering here for a sec..what happens when you place your A/C on the manual setting...do you have the same symptoms? I think (I knw, that's dangerous) that the temp sensor only comes into play when your setting is on auto. John On 6/21/05, Don Teresa Merriman [EMAIL PROTECTED] wrote: Hola Marshall Where do I look for this tube? Gracias Don On 6/21/05, Marshall Booth [EMAIL PROTECTED] wrote: Marshall Booth wrote: If the temp sensor doesn't have sufficient air drawn across it (if the venturi tube from the lower housing to the temp sensor) - perhaps because the foam tube has disintegrated, fan speed and/or temp control MAY become erratic. Should have read: If the temp sensor doesn't have sufficient air drawn across it (if the venturi tube from the lower housing to the temp sensor FAILS - perhaps because the foam tube has disintegrated) fan speed and/or temp control MAY become erratic. Sorry about that. Marshall -- Marshall Booth (who doesn't respond to unsigned questions) der Dieseling Doktor [EMAIL PROTECTED] '87 300TD 181Kmi,'87 190D 2.5 199Kmi, '84 190D 2.2 227Kmi, '85 190D 2.0 159Kmi, '87 190D 2.5 turbo 234kmi Diesel Technical Advisor MBCA, member GWSection http://www.dhc.net/~pmhack/mercedes/mbooth1.htm ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com For repairs see www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net -- Don Teresa Merriman Market Place Mexico Vacation Rentals Property Administration ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com For repairs see www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net
Re: [MBZ] Air Conditioning Mystery
the temp sensor is above the mirror behind a little plastic grill...i assume that any tube would be nearby...you can test the tube with smoke...if it goes into the little opening, it's not cloged ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com For repairs see www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net ---BeginMessage--- Hola Marshall Where do I look for this tube? Gracias Don On 6/21/05, Marshall Booth [EMAIL PROTECTED] wrote: Marshall Booth wrote: If the temp sensor doesn't have sufficient air drawn across it (if the venturi tube from the lower housing to the temp sensor) - perhaps because the foam tube has disintegrated, fan speed and/or temp control MAY become erratic. Should have read: If the temp sensor doesn't have sufficient air drawn across it (if the venturi tube from the lower housing to the temp sensor FAILS - perhaps because the foam tube has disintegrated) fan speed and/or temp control MAY become erratic. Sorry about that. Marshall -- Marshall Booth (who doesn't respond to unsigned questions) der Dieseling Doktor [EMAIL PROTECTED] '87 300TD 181Kmi,'87 190D 2.5 199Kmi, '84 190D 2.2 227Kmi, '85 190D 2.0 159Kmi, '87 190D 2.5 turbo 234kmi Diesel Technical Advisor MBCA, member GWSection http://www.dhc.net/~pmhack/mercedes/mbooth1.htm ___ For used parts email [EMAIL PROTECTED] For new parts see www.buymbparts.com http://www.buymbparts.com For repairs see www.oldworldauto.com http://www.oldworldauto.com To Unsubscribe or change delivery options go to: http://striplin.net/mailman/listinfo/mercedes_striplin.net -- Don Teresa Merriman Market Place Mexico Vacation Rentals Property Administration ---End Message---
Re: [MBZ] Air Conditioning Mystery
Don Teresa Merriman wrote: Hola Marshall Where do I look for this tube? The tube (made from foam tubing that usually will disintegrate after aging 12-15 years) goes from the blower housing to the cabin temp sensor - I've not worked on 126s, but I understand the sensor could be on the dash in earliest 126s and above the rear-view mirror/front cabin light in cars built after 7/81. Check out 83-640 in the Climate Control Manual or on the CD (I've attached the file). It only tangentially refers to the air hose, but it's the air hose that disintegrates. The hose goes from the blower housing to the dash mounted temp sensor in the early models and from the blower housing to the A pillar where it goes up and over to the ceiling mounted sensor in the later models (up 'til the mid '80s when there was another change). The use of foam (people have used the foam insulation for water pipes to replace it) reduces noise - if you use rubber or solid plastic hose it will transmit SOME noise, but MIGHT last more than 15 years! Marshall -- Marshall Booth (who doesn't respond to unsigned questions) der Dieseling Doktor [EMAIL PROTECTED] '87 300TD 181Kmi,'87 190D 2.5 199Kmi, '84 190D 2.2 227Kmi, '85 190D 2.0 159Kmi, '87 190D 2.5 turbo 234kmi Diesel Technical Advisor MBCA, member GWSection http://www.dhc.net/~pmhack/mercedes/mbooth1.htm 83-640.pdf Description: Adobe PDF document
