Hello,

My heater and A/C blow very weak on my w116, especially compared to my w123.

Using the search function, I see that a few people have put in a w126 blower to replace the w116.

I am thinking of going to the junkyard to see if I can find a 126 blower motor. Those of you who have a 116, do you have the same problem? Just checking first to see if there is anything else that could be causing this, like leaks, low voltage to the the blower motor, things like that.

Thanks for any input!

Ok so today I was driving to work, and pushed the defrost button..... it blew very hard for a few seconds, then it went down to slower speed.

So it sounds like the blower should be ok, but for some reason not getting full power.

Anyone experience this or know how to make the blower function at full speed?

I'd check the voltage at the fan. You can remove the glovebox and access the wire with a pointy multi-meter probe to determine voltage. If you search on my name and 116 blower you will see that I had recent blower problems caused by a failed amplifier. Your amp could be failing and causing your problem. When my blower is operating correctly, I notice no problems with its speed.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Hello Kerry,

Thanks for the information on your post. Did the search and found your post about the blower / amp.

I will try testing voltage when I get home from work.

I see that the amplifiers are VERY expensive. Is there a way to bypass the amp and make the blower always run at high speed? Could I just bypass the amp so when I push the HI button it just sends 12 volts to the blower?

I also see there is a 126 at my local junkyard, where I was going to get the blower motor from. Would a 126 amp work in my 116?

Thanks!

The blower in my 123 was working fine one minute and not at all the next so I checked the fuses and found a very corroded but still intact fuse in the box. I put a new fuse in and all is working fine again

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1981 240D 143k 4 spd manual -SOLD

2004 VW Jetta TDI 5 speed 300k -still driven daily

Don't know how to bypass the amp and still get control with the 'Hi' button. But I did decide that if the amp was not the problem, I could wire a separate switch with 12 volts going directly to the fan so I could get hot air until I was able to do further diagnosis. Don't know what else fails to work when the amp goes out, but you can definitely get the blower to blow without it.
Since Defrost mode is the default mode in the servo, I suspect that with a bad amp, the system will resort to putting everything in defrost.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13