Blower - Revision history

W220.ee at 14:28, 20 July 2021

2021-07-20T14:28:54Z

← Older revision		Revision as of 14:28, 20 July 2021
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	Use a 10 gauge 40A fuse link and install a new line from the small positive 12V lug located in the passenger footwell. Cut the original Blower Regulator supply wire a couple inches back from the regulator plug and install a compression connector to the new line. Make sure the new supply line and all the connectors are well insulated and cannot be damaged by passengers.		Use a 10 gauge 40A fuse link and install a new line from the small positive 12V lug located in the passenger footwell. Cut the original Blower Regulator supply wire a couple inches back from the regulator plug and install a compression connector to the new line. Make sure the new supply line and all the connectors are well insulated and cannot be damaged by passengers.

			= Repair ACC Blower Motor =

			'''The Issue'''

			Several BenzWorld Members have had trouble with the ACC Blower Motor regulator multiple times on different M-B models. In some cases, they found that the motor rotor was hard to turn. This caused a high current draw and if not caught in time fries the regulator components. After freeing up the motor, the unit will work again. But the root cause of the problem seems to be corrosion of the motor assembly due to excessive moisture due to blocked drains and debris in the plenum. This is another example of poor M-B design. Frequent checks and maintenance in this area must be conducted.

			'''DIY ACC Blower Motor Regulator Replacement'''

			Reference: http://www.benzworld.org/forums/w140-s-class/1453091-diy-blowser-regulator-replacement-diagnosis.html

			It's a 10-15 minute job if you take your time, and this repair worked wonders for my car's A/C!

			I got my blower regulator off eBay for $75 with a supposedly German OEM supplier: Hamburg Technic. I called stealership and they quoted $292 and $399 for two brands. I didn't ask but assume it's Bosch or equivalent. Autohaus has German name brands for ~$170-230 so I took a chance with eBay.

			Tools needed: Philips screwdriver #2 and Torx-20 driver.

			Symptoms: Very weak air flow especially though out the day in Dallas, TX heat. I noticed air flow getting weaker in a period of a month. So I broke out my Fluke DVM and only measured 2-3VDC across the blower terminals. If your press REST on the climate controls for 10sec. you get into the diagnostic mode. I pressed the left AUTO button to cycle up to step 10 then adjusted (+-) fan buttons. On MAX, I only measured 4VDC. First start up in the morning yielded me 7VDC but still didn't flow a lot. When I commanded 1 or 2 bars (MIN), I got 1VDC.

			'''DIY ACC Blower Motor Regulator Repair'''

			Reference: http://www.benzworld.org/forums/w140-s-class/1470248-blower-regulator-electronics.html#post3706621

			Summary: The power transistor driving the motor is actually an N-channel power MOSFET (BTS282Z) which incorporates two temperature sensors mounted on the chip (making it a TEMPFET), sensing the gate and source temperatures. I think the MOSFET operates pretty much as dmac described, allowing for the difference in transistor type. The regulator also contains a pcb with one IC on it - a 14-pin DIP - which carries the IDs: 2901 and 90H815. From the 2901, I guess this is a quad comparator. The rest of the circuitry was not decodable. I assume the four comparators are used with the temperature sensors to stabilise the motor speed as the chip's temperature changes - also to protect the chip, although they don't seem too good at that. The 14-pin DIP would definitely needs its own 12 V line and I think that this is provided by the red connection to pin 4 of the regulator.

W220.ee: /* Testing Control Voltage - Blower Motor */ moved content from page ACC_Blower_Control_Voltage_Typical_Results

2021-07-20T13:08:13Z

Testing Control Voltage - Blower Motor: moved content from page ACC_Blower_Control_Voltage_Typical_Results

@@ Line 80: / Line 80: @@
 MOS500  had these symptoms: Very weak air flow especially though out the day in Dallas, TX heat. I noticed air flow getting weaker in a period of a month. So I broke out my Fluke DVM and only measured 2-3VDC across the blower terminals. If you press REST on the climate controls for 10sec. you get into the diagnostic mode. (See [[Automatic Climate Control (ACC) Service Menus]].) I pressed the left AUTO button to cycle up to step 10 then adjusted (+-) fan buttons. On MAX, I only measured 4VDC. First start up in the morning yielded me 7VDC but still didn't flow a lot. When I commanded 1 or 2 bars (MIN), I got 1VDC. For Service Menus see here: [[Automatic Climate Control (ACC) Service Menus]]
-[[ACC Blower Control Voltage Typical Results]]
+====ACC Blower Control Voltage Typical Results====
 ===Worn Brushes and Commutator - Blower Motor===

Ricebubbles: /* Diagnosis/Testing - Blower Motor */

2020-01-01T02:23:42Z

Diagnosis/Testing - Blower Motor

← Older revision		Revision as of 02:23, 1 January 2020
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	* Eventually a Blower Motor's brushes and commutator will wear to the point where the motor will cease to work.		* Eventually a Blower Motor's brushes and commutator will wear to the point where the motor will cease to work.

	==Diagnosis/Testing - Blower Motor==		==Diagnosis/Testing - Blower Motor and Fuse f33==
	===High Resistance in Supply Line - Blower Motor===		===High Resistance in Supply Line and/or Fuse f33 - Blower Motor===
	The Blower Regulator A32n1 is connected to a constant supply of +12V via Circuit 30 in the Right Front Fuse and Relay Module K40/7. What commonly happens is that a small resistance develops somewhere in the line due to oxidization or corrosion and this generates a small amount of heat which then accelerates the failure, eventually melting plastic and making the resistance even higher and making the problem worse. It can easily cause a fire so should be attended to asap.		The Blower Regulator A32n1 is connected to a constant supply of +12V via Circuit 30 in the Right Front Fuse and Relay Module K40/7. What commonly happens is that a small resistance develops somewhere in the line due to oxidization or corrosion and this generates a small amount of heat which then accelerates the failure, eventually melting plastic and making the resistance even higher and making the problem worse. It can easily cause a fire so should be attended to asap.

Ricebubbles: /* Control Voltage - Blower Motor */

2020-01-01T02:19:10Z

Control Voltage - Blower Motor

← Older revision		Revision as of 02:19, 1 January 2020
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	[[File:W220 Over Heated Blower Fuse f33.JPG\|500px\|center]]		[[File:W220 Over Heated Blower Fuse f33.JPG\|500px\|center]]

	===Control Voltage - Blower Motor===		===Testing Control Voltage - Blower Motor===
			Reference: http://www.benzworld.org/forums/w140-s-class/1453091-diy-blowser-regulator-replacement-diagnosis.html

			MOS500 had these symptoms: Very weak air flow especially though out the day in Dallas, TX heat. I noticed air flow getting weaker in a period of a month. So I broke out my Fluke DVM and only measured 2-3VDC across the blower terminals. If you press REST on the climate controls for 10sec. you get into the diagnostic mode. (See [[Automatic Climate Control (ACC) Service Menus]].) I pressed the left AUTO button to cycle up to step 10 then adjusted (+-) fan buttons. On MAX, I only measured 4VDC. First start up in the morning yielded me 7VDC but still didn't flow a lot. When I commanded 1 or 2 bars (MIN), I got 1VDC. For Service Menus see here: [[Automatic Climate Control (ACC) Service Menus]]

	[[ACC Blower Control Voltage Typical Results]]		[[ACC Blower Control Voltage Typical Results]]

Ricebubbles: /* DIY Procedures - Blower Motor */

2020-01-01T02:14:04Z

DIY Procedures - Blower Motor

← Older revision		Revision as of 02:14, 1 January 2020
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	===Blower Regulator - Removing/Replacing===		===Blower Regulator - Removing/Replacing===

	http://www.benzworld.org/forums/w220-s-class/1518325-how-do-i-get-my-c.html		Reference: http://www.benzworld.org/forums/w220-s-class/1518325-how-do-i-get-my-c.html

	* Post #8 by Gabby07621 shows how to remove the Blower Motor and hence the Blower Regulator.		* Post #8 by Gabby07621 shows how to remove the Blower Motor and hence the Blower Regulator.
	* Post #16 and Post #23 by cowboyt issue a warning about replacing the Blower Regulator. Make sure to read and double check the part number before ordering a replacement. The Regulator part number has been superseded by 2308216451 (or A-230-821-64-51).		* Post #16 and Post #23 by cowboyt issue a warning about replacing the Blower Regulator. Make sure to read and double check the part number before ordering a replacement. The Regulator part number has been superseded by 2308216451 (or A-230-821-64-51).

	~~===Overcoming a High Resistance in Blower Regulator (and Motor) Fuse f33===~~		Reference: http://www.benzworld.org/forums/w140-s-class/1453091-diy-blowser-regulator-replacement-diagnosis.html
	If the Blower Regulator (and Motor) Fuse f33 is so severely damaged that it is beyond repair, one method to restore a working Blower Regulator and Motor is to bypass the Blower Regulator Supply Line completely.

	~~Use~~ a 10 gauge 40A fuse link and install a new line from the small positive 12V lug located in the passenger footwell. Cut the original Blower Regulator supply wire a couple inches back from the regulator plug and install a compression connector to the new line. Make sure the new supply line and all the connectors are well insulated and cannot be damaged by passengers.		MOS500 states it's a 10-15 minute job if you take your time.

	~~===Regulator Repair===~~		I got my blower regulator off eBay for $75 with a supposedly German OEM supplier: Hamburg Technic. I called stealership and they quoted $292 and $399 for two brands. I didn't ask but assume it's Bosch or equivalent. Autohaus has German name brands for ~$170-230 so I took a chance with eBay.

	~~Reference~~: ~~http://www.benzworld.org/forums/w140~~-~~s-class/1470248-blower-regulator-electronics~~.~~html#post3706621~~		Tools needed: Philips screwdriver #2 and Torx-20 driver.

	~~Summary~~: ~~The power transistor driving~~ the ~~motor is actually an N-channel power MOSFET (BTS282Z) which incorporates two temperature sensors mounted on the chip (making it a TEMPFET)~~, ~~sensing the gate and source temperatures~~. I ~~think the MOSFET operates pretty much as dmac described, allowing for the difference~~ in ~~transistor type. The regulator also contains~~ a ~~pcb with one IC on it -~~ a ~~14-pin DIP~~ - ~~which carries~~ the ~~IDs: 2901 and 90H815~~. ~~From~~ the ~~2901, I guess this is a quad comparator~~. ~~The rest of~~ the ~~circuitry was not decodable~~. I ~~assume~~ the ~~four comparators are used with the temperature sensors~~ to ~~stabilise the motor speed as the chip's temperature changes~~ - ~~also to protect~~ the ~~chip, although they don~~'t ~~seem too good at that~~. ~~The 14-pin DIP would definitely needs its own 12 V line and~~ I ~~think that this is provided by the red connection to pin 4 of the regulator~~.		Symptoms: Very weak air flow especially though out the day in Dallas, TX heat. I noticed air flow getting weaker in a period of a month. So I broke out my Fluke DVM and only measured 2-3VDC across the blower terminals. If you press REST on the climate controls for 10sec. you get into the diagnostic mode. (See [[Automatic Climate Control (ACC) Service Menus]].) I pressed the left AUTO button to cycle up to step 10 then adjusted (+-) fan buttons. On MAX, I only measured 4VDC. First start up in the morning yielded me 7VDC but still didn't flow a lot. When I commanded 1 or 2 bars (MIN), I got 1VDC. For Service Menus see here: [[Automatic Climate Control (ACC) Service Menus]]

	===Regulator ~~Replacement~~===		===Blower Regulator - Repair===

	Reference: http://www.benzworld.org/forums/w140-s-class/~~1453091~~-~~diy-blowser~~-regulator-~~replacement-diagnosis~~.html		Reference: http://www.benzworld.org/forums/w140-s-class/1470248-blower-regulator-electronics.html#post3706621

	It's ~~a 10~~-~~15 minute job if you take your time~~, and this ~~repair worked wonders for my car's A/C!~~		Summary: The power transistor driving the motor is actually an N-channel power MOSFET (BTS282Z) which incorporates two temperature sensors mounted on the chip (making it a TEMPFET), sensing the gate and source temperatures. I think the MOSFET operates pretty much as dmac described, allowing for the difference in transistor type. The regulator also contains a pcb with one IC on it - a 14-pin DIP - which carries the IDs: 2901 and 90H815. From the 2901, I guess this is a quad comparator. The rest of the circuitry was not decodable. I assume the four comparators are used with the temperature sensors to stabilise the motor speed as the chip's temperature changes - also to protect the chip, although they don't seem too good at that. The 14-pin DIP would definitely needs its own 12 V line and I think that this is provided by the red connection to pin 4 of the regulator.

	~~I got my blower regulator off eBay for $75 with~~ a ~~supposedly German OEM supplier: Hamburg Technic. I called stealership~~ and ~~they quoted $292~~ and ~~$399 for two brands. I didn't ask but assume~~ it~~'s Bosch or equivalent. Autohaus has German name brands for ~$170-230 so I took~~ a ~~chance with eBay~~.		===Overcoming a High Resistance in ACC Blower Regulator (and Motor) Fuse f33===
			If the Blower Regulator (and Motor) Fuse f33 is so severely damaged that it is beyond repair, one method to restore a working Blower Regulator and Motor is to bypass the Blower Regulator Supply Line completely.

	~~Tools needed: Philips screwdriver #2~~ and ~~Torx-20 driver.~~		Use a 10 gauge 40A fuse link and install a new line from the small positive 12V lug located in the passenger footwell. Cut the original Blower Regulator supply wire a couple inches back from the regulator plug and install a compression connector to the new line. Make sure the new supply line and all the connectors are well insulated and cannot be damaged by passengers.

	~~Symptoms: Very weak air flow especially though out~~ the ~~day~~ in ~~Dallas, TX heat~~. ~~I noticed air flow getting weaker in~~ a ~~period of~~ a ~~month. So I broke out my Fluke DVM and only measured 2-3VDC across~~ the ~~blower terminals~~. ~~If you press REST on~~ the ~~climate controls for 10sec. you get into~~ the diagnostic mode. I pressed the left AUTO button to cycle up to step 10 then adjusted (+-) fan buttons. On MAX, I only measured 4VDC. First start up in the morning yielded me 7VDC but still didn't flow a lot. When I commanded 1 or 2 bars (MIN), I got 1VDC. ~~For Service Menus see here: [[Automatic Climate Control (ACC) Service Menus]]~~

Ricebubbles: /* Blower Motor Replacement */

2020-01-01T02:01:09Z

Blower Motor Replacement

← Older revision		Revision as of 02:01, 1 January 2020
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	[[Under Hood ACC Drain Access and Cleaning]]		[[Under Hood ACC Drain Access and Cleaning]]

	===Blower Motor ~~Replacement~~===		===Blower Motor - Removing Repairing Replacing===
	[[Blower Motor Removing ~~Repairing~~ Replacing]]		http://www.benzworld.org/forums/w220-s-class/1518325-how-do-i-get-my-c.html

			* Post #8 by Gabby07621 shows how to remove the Blower Motor.

			===Blower Regulator - Removing/Replacing===

			http://www.benzworld.org/forums/w220-s-class/1518325-how-do-i-get-my-c.html

			* Post #8 by Gabby07621 shows how to remove the Blower Motor and hence the Blower Regulator.
			* Post #16 and Post #23 by cowboyt issue a warning about replacing the Blower Regulator. Make sure to read and double check the part number before ordering a replacement. The Regulator part number has been superseded by 2308216451 (or A-230-821-64-51).

	===Overcoming a High Resistance in Blower Regulator (and Motor) Fuse f33===		===Overcoming a High Resistance in Blower Regulator (and Motor) Fuse f33===

Ricebubbles: /* Control Voltage - Blower Motor */ Added new section Worn Brushes and Commutator - Blower Motor

2020-01-01T01:45:06Z

Control Voltage - Blower Motor: Added new section Worn Brushes and Commutator - Blower Motor

@@ Line 77: / Line 77: @@
 ===Control Voltage - Blower Motor===
 [[ACC Blower Control Voltage Typical Results]]
 ==DIY Procedures - Blower Motor==

Ricebubbles: /* Issues - Blower Motor */

2020-01-01T01:17:00Z

Issues - Blower Motor

← Older revision		Revision as of 01:17, 1 January 2020
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	* ACC Blower Motor hard to turn due to corrosion. This causes a high current draw and if not caught in time permanently damages the motor speed regulator components.		* ACC Blower Motor hard to turn due to corrosion. This causes a high current draw and if not caught in time permanently damages the motor speed regulator components.
	* Root cause of the many blower issues seems to be corrosion of the motor assembly due to excessive moisture due to blocked drains and debris in the plenum.		* Root cause of the many blower issues seems to be corrosion of the motor assembly due to excessive moisture due to blocked drains and debris in the plenum.
	* A ~~blower motor~~ seized due to corrosion can be freed up but if the cause of the moisture is not addressed the issue will reoccur.		* A Blower Motor seized due to corrosion can be freed up but if the cause of the moisture is not addressed the issue will reoccur.
			* Eventually a Blower Motor's brushes and commutator will wear to the point where the motor will cease to work.

	==Diagnosis/Testing - Blower Motor==		==Diagnosis/Testing - Blower Motor==

Ricebubbles: /* High Resistance in Supply Line - Blower Motor */

2017-11-19T08:44:31Z

High Resistance in Supply Line - Blower Motor

← Older revision		Revision as of 08:44, 19 November 2017
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	* Both in and out terminals of Blower Fuse Connector X64/1.		* Both in and out terminals of Blower Fuse Connector X64/1.
	* MR1 Pin 2 in the Right Front Fuse and Relay Module K40/7.		* MR1 Pin 2 in the Right Front Fuse and Relay Module K40/7.
	* Both sides of Fuse f33 in the Right Front Fuse and Relay Module K40/7.		* Both sides of Fuse f33 in the Right Front Fuse and Relay Module K40/7. ([[Fuses]])
	* And the connectors and junctions in circuit 30 where it goes from the Right Front Fuse and Relay Module K40/7 to the battery. Exact details TBD.		* And the connectors and junctions in circuit 30 where it goes from the Right Front Fuse and Relay Module K40/7 to the battery. Exact details TBD.

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	The best way to do this is to take a reasonably heavy wire from the +12V in the passenger foot well and connect it to Pin 3 RDYE (Red Yellow) in the Blower Regulator A32n1. It would be a good idea to use a 40A fuse in this hot wire connection just as a precaution. It is not absolutely necessary to remove the original Red Yellow wire from Pin 3 for this test. Just remove Fuse f33 in the Right Front Fuse and Relay Module K40/7.		The best way to do this is to take a reasonably heavy wire from the +12V in the passenger foot well and connect it to Pin 3 RDYE (Red Yellow) in the Blower Regulator A32n1. It would be a good idea to use a 40A fuse in this hot wire connection just as a precaution. It is not absolutely necessary to remove the original Red Yellow wire from Pin 3 for this test. Just remove Fuse f33 in the Right Front Fuse and Relay Module K40/7.

	Once the hot wire is in place and the Fuse f33 removed, switch on the ACC and command the blower to run at maximum speed.		Once the hot wire is in place and the Fuse f33 removed ([[Fuses]]), switch on the ACC and command the blower to run at maximum speed.

	If the Blower still does not work you will have to start the diagnosis again.		If the Blower still does not work you will have to start the diagnosis again.
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	\|}		\|}

	It may be a bit difficult to determine which side of X64/1 is which, so just measure both sides separately and record the results. The same comment applies to Fuse f33.		It may be a bit difficult to determine which side of X64/1 is which, so just measure both sides separately and record the results. The same comment applies to Fuse f33 ([[Fuses]]).

	When you find the Test Point where the voltage does not change with load you are one step upstream of the fault. That is if the X64/1 side of Fuse f33 drops to zero on load and the other side, the Circuit 30 side of Fuse f33 doesn't then the issue is with Fuse f33.		When you find the Test Point where the voltage does not change with load you are one step upstream of the fault. That is if the X64/1 side of Fuse f33 drops to zero on load and the other side, the Circuit 30 side of Fuse f33 doesn't then the issue is with Fuse f33.

Ricebubbles: /* High Resistance in Supply Line - Blower Motor */

2015-11-09T11:56:46Z

High Resistance in Supply Line - Blower Motor

← Older revision		Revision as of 11:56, 9 November 2015
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	With acknowledgement to BenzWorld member 'cmitch' here is a photo of an overheated Fuse f33. Note the melted fuse socket.		With acknowledgement to BenzWorld member 'cmitch' here is a photo of an overheated Fuse f33. Note the melted fuse socket.
	[[File:W220 Over Heated Blower Fuse f33.JPG\|500px\|center]]		[[File:W220 Over Heated Blower Fuse f33.JPG\|500px\|center]]

	~~'''One Method of Overcoming a High Resistance in Fuse f33'''~~

	~~If the Fuse f33 is so severely damaged that it is beyond repair, one method to restore a working Blower Motor is to bypass the Blower Regulator Supply Line completely.~~

	Use a 10 gauge 40A fuse link and install a new line from the small positive 12V lug located in the passenger footwell. Cut the original Blower Regulator supply wire a couple inches back from the regulator plug and install a compression connector to the new line. Make sure the new supply line and all the connectors are well insulated and cannot be damaged by passengers.

	===Control Voltage - Blower Motor===		===Control Voltage - Blower Motor===