Just changed the motor of the blower,

is turning when key on, does NOT turn off threw the climate control,

Disconected the climate control two plugs,

Still on,

What did I wrong again?

Did I wired it wrong ,+to - ?

thanks in advance,

300SDL, california,

Brushes where bed ,

Fan speed control is probably toast (shorted transistor). It's the module with the heatsink on it up in the blower housing.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

Thanks for replying,

any idea of replacing the power transistor ?

could not find information,

Thanks again,

You have to replace the entire module, it's encapsulated in epoxy. If the fan motor were in poor condition, the brushes arcing badly enough can cause the transistor to fail in a shorted condition. When it does, it doesn't matter what button you push on the CCU, the fan will always run max speed.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

Thank you Diesel300

Diesel300 is smarter than me. OP just stated "300SDL". Does that tell a year range? Also "Brushes where bed" might mean something.

My 84-85 300D have just mechanical relays in the "blower control box". Even my 1996 Voyager has mechanical switches and resistors. My 2002 T&C blower is transistor controlled, but only because the optional digital ATC. It similarly runs "always high-speed" when the transistor "resistor"-pack fails, though it can be turned off.

__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

300SDL means it's a 1986-1987 model. Unlike the earlier models with relays and an actual blower "resistor", the 1986+ cars are solid state with a transistor pack in the blower plenum. On the SDL's the key switch has a dedicated contact to the blower motor, if the transistor pack fails shorted, the blower will run when the key is on, but not when the key is off, and always at the same speed regardless of input from the CCU.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

Did order Heater Blower Motor Regulator Resistor 1298213351 For Mercede 300SL 500SL SL320
( 202141416589 )

From Ebay, $20,

Looks similar to my control,

Will give it a try,

I have an ‘87 SDL that the blower will come on in the off position. It will also quit in the on position. If the fan is set to low speed then the blower will come on on it’s on going down the road at low speed. If it’s set on high speed then it can also come on on it’s on at high speed even with the switch clearly in the off position. If I press the off button and hold it then the blower will stay off until I release the switch. Sometimes it will stay off until I press a selection on the climate control unit. Every time it comes on on it’s on the AC compressor comes on too. In other words, mine comes on with the key switch 95% of the time and blows according to the selected fan speed. It will shut off on it’s on. Every time it’s on the AC compressor is on. I hate electronics! ��

Did the spare part fix it ? .

-Nate

The pushbutton units are well known for bad solder joints, especially on the push button switches themselves. Poor connections or broken solder joints will cause the behavior you're describing, the biggest indication being that it will stay off if you hold the "off" switch.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

? Who re solders them ? .

I bought a rebuilt one from that place in Florida, they don't .

TIA,

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

The 1986+ cars are very different from the earlier cars. The PBU is full of electronics. Opening the unit and unclipping the PCB's will get it to where you can work on it yourself. Resoldering is a DIY job if you know how to solder.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

I replaced the control panel with one of my spares and all is well. Thanks!