|
|
|
#1
|
|||
|
|||
300SDL Blower inop, crazy question...
Could it be the outboard temp sensor? I found mine unplugged, and the compressor is locked up (just bought the car) I am getting zero response from the blower on any setting. I'm getting power at the fuse in the big box, but have yet to check the one by the firewall. Thanks in advance for any info…lost here
|
#2
|
||||
|
||||
I don't know how hard it is to get at the Blower itself but maybe that is also unplugged. Once you locate the Connector at the Blower try to jumper wire connected to a 12 Volt Voltage Source the Blower to see if it moves.
__________________
84 300D, 82 Volvo 244Gl Diesel |
#3
|
||||
|
||||
The motor itself is under the glovebox...couple of screws and you are there. There is also a primitive looking resistor (spring within a metal box with holes) on the pass. side fender (in the engine compartment).
__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein 09 Jetta TDI 1985 300D |
#4
|
|||
|
|||
Also Could be the Ignition Switch
Try twisting the key left (counter clockwise) a "hair or two" from the run position. The contacts seem to wear over time...
So start the motor and then with a blower setting of low or high, turn the key a touch to the left.
__________________
1986 300SDL 440,xxx |
#5
|
||||
|
||||
Quote:
You've got to isolate the motor, in order to see if it is operable. To my knowledge, the outside ambient temperature meter has nothing to do with that possibility. |
#6
|
||||
|
||||
We also need the OP to clarify what year his 126 is.
1985 or older 126s have the 123-style ACC 1986 or newer 126s have the 124-style ACC The control panels look almost the same but everything else behind the panel is completely different. The only visible difference from the front of the panel is the Auto button between the High and Low Fan buttons. On the 123-style the Auto button is a small white button, and on the 124-style it is the same size black button as the other two fan buttons. 123-style ACC uses the stepped resistor and relay box for blower speed control. The blower is under the glove box on the passenger side. 124-style ACC uses a PWM controller for continuous fan speed control. The controller and fan are located on the engine bay side of the firewall under the wiper mechanism.
__________________
The OM 642/722.9 powered family Still going strong 2014 ML350 Bluetec (wife's DD) 2013 E350 Bluetec (my DD) both my kids cars went to junkyard in 2023 2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles) 2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles) 1998 E300DT sold to TimFreeh 1987 300TD sold to vstech |
#7
|
||||
|
||||
If it's an 86, 87, 90 or 91 SDL, it'll have a PWM blower motor controller by the blower motor under the glove box. None of the remove the wiper mechanism foolishness in a 124. No primitive resistor box for the blower.
Sixto MB-less |
#8
|
||||
|
||||
Oh wow I thought the gen II 126s were just like the 124s. Learn something every day.
I just went through the blower-wiper-ectomy on my 124. No fun.
__________________
The OM 642/722.9 powered family Still going strong 2014 ML350 Bluetec (wife's DD) 2013 E350 Bluetec (my DD) both my kids cars went to junkyard in 2023 2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles) 2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles) 1998 E300DT sold to TimFreeh 1987 300TD sold to vstech |
#9
|
||||
|
||||
Could be the blower motor regulator (aka bed of nails) that translates the signals from the push button unit into signals for the blower motor.
Our 420SEL had this problem. You just need to probe the connector and see if you get 0-7V when you set the blower on high/low. If you observe no change then its could be a problem in your push button unit.
__________________
Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out. Check here for compatibility, diagnostics, and availability! (4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!) 82 300SD 145k 89 420SEL 210k 89 560SEL 118k 90 300SE 262k RIP 5/25/2010 90 560SEL 154k 91 300D 2.5 Turbo. 241k 93 190E 3.0 235k 93 300E 195k |
#10
|
|||
|
|||
Wow, am I glad to have found this forum!!! The car is an 86 300SDL with close to 400K according to Carfax. I bought it under the impression that the working odo was accurate, but apparently it's been changed. No matter, nice orig. car esp for the miles for 2K in my opinion. I tried backing off the ignition a hair and no go, but thanks for the tip. I'm sure it'll eventually pop up, especially with the miles it has. I will look under the glove box by the blower for the controller and test it. I can't seem to find the "porcupine" anywhere, but I'll find it. I got the new compressor (salvage) today, and it was nearly 90 here in Atl today so I guess I need to get back at it. Where would I find the numbers on the head to see if it's been changed or it's the good one? Just curious, it runs great and maintains good temp with zero pressure on upper rad. hose.
Thanks again y'all, I REALLY appreciate your help! |
#11
|
||||
|
||||
Welcome to the forum. You might want to go to User CP and update your profile to list your location. Some of us love to go on "Mercedes" road trips to meet folks, deliver parts, turn wrenches, drink a beverage or two, and eat good food.
__________________
daw_two Germantown, TN Links: Sold last car --- 05/2012 1984 300D Light Ivory, Red interior Cluster Needles Paint New Old Stock (NOS) parts Past: 3/2008 1986 300SDL "Coda" 04/2010 1965 190D(c) "Ben" & many more |
#12
|
||||
|
||||
Quote:
__________________
Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out. Check here for compatibility, diagnostics, and availability! (4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!) 82 300SD 145k 89 420SEL 210k 89 560SEL 118k 90 300SE 262k RIP 5/25/2010 90 560SEL 154k 91 300D 2.5 Turbo. 241k 93 190E 3.0 235k 93 300E 195k |
#13
|
||||
|
||||
The cylinder head casting number is by the #2 injector. You should see a string of embossed numbers in the form 603 016 xx 01 where xx is the telling sequence. Following is a picture of a #22 casting -
Sixto MB-less |
#14
|
|||
|
|||
I don't know who to thank first, but you guys are great here. I apparently registered years ago and didn't come back until recently. I'm admittedly a terrible wrench, but smart enough to know to listen to people that know what they're doing. I couldn't even think about owning one of these cars if I had to pay somebody else to wrench on it. I've had a bunch of them W108/116/123/124/126/140 (gasser)210 and others I can't remember the body code for. I loved every one of them, and glad most people don't…so I can afford them. This 300SDL is one that I need to get straightened out as my new DD, which is currently a Husky 610SM that needs to go.
I got the porcupine out, it's laying on the floor still connected. I need to get another MM today, mine is MIA again. My inclination is that the control unit is bad, but that's just a guess. The radio (factory) is also curiously inop, and wonder if maybe it was flooded at some point. Thanks again y'all |
#15
|
||||
|
||||
A little background on how the porcupine operates. It is actually a PWM drive which sounds scary but really is very similar to a car stereo amplifier. It switches the dc supply on and off rapidly. It can vary how much time it spends 'on' and how much time it spends 'off' and that is how it changes the amount of energy delivered to the motor.
The way it knows how much "off" and "on" time to provide is based on the reference signal from the pushbutton controller unit. This is a dc voltage that varies from 0-6 V dc. 0 V = stop, 6 V = full speed. There are 3 wires going in from the car wiring harness, and 2 going out to the motor. Note that both sides of the motor connect to the controller. Neither motor wire has a direct connection to battery or ground. Red going in = dc+ from main fuse Black going in = ground to chassis Yellow going in = reference voltage from pushbutton controller Red/blue going out = to motor windings. Note that they arranged the quick connectors so that you cannot hook it up wrong to the motor (otherwise the motor would run backwards). Note that the heat sink is there because the transistors get warm in operation, and it requires a constant stream of cooling air over the heat sink. If you are testing with the regulator on the floor pay heed to this or it can damage the regulator. I would check that yellow wire first. With the system in High fan position, or Defrost, you should have about 6 V on that yellow wire. Also make sure you have 12 V dc on the red and black coming from the car side.
__________________
The OM 642/722.9 powered family Still going strong 2014 ML350 Bluetec (wife's DD) 2013 E350 Bluetec (my DD) both my kids cars went to junkyard in 2023 2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles) 2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles) 1998 E300DT sold to TimFreeh 1987 300TD sold to vstech |
Bookmarks |
Thread Tools | |
Display Modes | |
|
|