I have a rather odd problem with my acc unit. I thought I knew what the issue was by reading old threads but it didn't help the problem. The issue is I am only getting heat out of the outer vents, no matter where the temp wheel is placed, only hot air. The AC comp still comes on, also, when placed on AUTO, I don't get any other fan speed but low. I have tried another known good acc unit, but the same thing still happens. Any idea?
Thanks

__________________
-Randy Wakefield

1969 220D 4 speed (parts car)
1976 280C
1976 280S
1981 240D 4 speed (parts car)
1982 300D
1983 300TD (Ivory)
1983 300TD (gold)
1985 300TD (gray)
1987 190D 2.5
1970 280SEL (sold)
1977 240D 4 speed (sold)
1974 280 (rusted to death)
---
1927 Chevy 4 door sedan
1938 Chevy 2 door sedan
1950 Willys Jeepster
1955 Studebaker President 4 door
1977 Ford F250
1979 Glastron 17'
1948 John Deere A
1960 John Deere 2010
1979 Satoh S650G
--
2000 Bichon (Doby)

1976 280C
1976 280S
1982 300D
1983 300TD (Ivory)
1983 300TD (gold)
1985 300TD (gray)
1987 190D 2.5
1970 280SEL (sold)
1977 240D 4 speed (sold)
1974 280 (rusted to death)
---
1927 Chevy 4 door sedan
1938 Chevy 2 door sedan
1950 Willys Jeepster
1955 Studebaker President 4 door
1977 Ford F250
1979 Glastron 17'
1948 John Deere A

Which one of the FLEET has this problem?????

__________________
My Truck.. 2007 DODGE, 5.9 Cummins, 6spd stick, 4X4. My car..1977 240D, OTHER WHEELS...1955 VW Oval window bug, European Delivery (Holland) with a 1700cc, 2 barrel, Porsche drum brakes. 1939 WILLYS Pick-up. 1967 Triumph 200cc Tiger Cub. 1976 Honda 550F 4cyl Motor Cycle.

I will give seven to one odds it's not the Deere!!!

Maybe it's the boat.

OMG.....I must be losing my mind.....Its for the ivory 300TD wagon. Thats funny, I could never get the heat to work on the Deere.....haha..
Thanks again!

__________________
-Randy Wakefield

1969 220D 4 speed (parts car)
1976 280C
1976 280S
1981 240D 4 speed (parts car)
1982 300D
1983 300TD (Ivory)
1983 300TD (gold)
1985 300TD (gray)
1987 190D 2.5
1970 280SEL (sold)
1977 240D 4 speed (sold)
1974 280 (rusted to death)
---
1927 Chevy 4 door sedan
1938 Chevy 2 door sedan
1950 Willys Jeepster
1955 Studebaker President 4 door
1977 Ford F250
1979 Glastron 17'
1948 John Deere A
1960 John Deere 2010
1979 Satoh S650G
--
2000 Bichon (Doby)

The vacuum valve is bad....need replacing...and to do it it requires that you remove the dash...so if you decide to do it, you may as well replace them all while you're at it, and consider the whole thing....afterall, that's not a job you want to do twice...

This link may help you: http://www.peachparts.com/shopforum/diesel-discussion/80341-order-installing-evap-box-w123-post526705.html#post526705

I know this one will, it shows the piece that's bad on your car....: Dash removal ---- Not That Bad

Good luck, if you want to do it twice, my wifes 300D needs this done....

__________________
1998 W202 C230 - The money pit of late.
1984 W126 300SD (356,800 miles) Gone to the wrenchapart
1984 W123 300D Gone to the wrenchapart
1972 W108 280SE 3.5 (sold but not forgotten)
1986 Buick Grand National 3.8l Turbo (86k miles)
1966 Glassic Model 'A' Replica http://www.glassicannex.org

http://banners.wunderground.com/weat...Round_Rock.gif

Is temperature and fan speed controlled by vacuum?

No, I don't think vacuum is the problem. If only the center vents didn't work, then it would be vac, but the heat is on all the time, no matter where the wheel is set, and the fan speeds don't change. I'm thinking resistor, but why won't the heat shut off, bad mono? But why all at once? Luck?

__________________
-Randy Wakefield

1969 220D 4 speed (parts car)
1976 280C
1976 280S
1981 240D 4 speed (parts car)
1982 300D
1983 300TD (Ivory)
1983 300TD (gold)
1985 300TD (gray)
1987 190D 2.5
1970 280SEL (sold)
1977 240D 4 speed (sold)
1974 280 (rusted to death)
---
1927 Chevy 4 door sedan
1938 Chevy 2 door sedan
1950 Willys Jeepster
1955 Studebaker President 4 door
1977 Ford F250
1979 Glastron 17'
1948 John Deere A
1960 John Deere 2010
1979 Satoh S650G
--
2000 Bichon (Doby)

Guess I should have specified that I was referring to the no air from center vents part of the question....

__________________
1998 W202 C230 - The money pit of late.
1984 W126 300SD (356,800 miles) Gone to the wrenchapart
1984 W123 300D Gone to the wrenchapart
1972 W108 280SE 3.5 (sold but not forgotten)
1986 Buick Grand National 3.8l Turbo (86k miles)
1966 Glassic Model 'A' Replica http://www.glassicannex.org

http://banners.wunderground.com/weat...Round_Rock.gif

When my Alternator went out a few weeks ago, all I got was hot air and I couldn't turn it off no matter what.

Not saying that's what's wrong with yours, but I had that and other weird things happen till I fixed it.

__________________
1998 W202 C230 - The money pit of late.
1984 W126 300SD (356,800 miles) Gone to the wrenchapart
1984 W123 300D Gone to the wrenchapart
1972 W108 280SE 3.5 (sold but not forgotten)
1986 Buick Grand National 3.8l Turbo (86k miles)
1966 Glassic Model 'A' Replica http://www.glassicannex.org

http://banners.wunderground.com/weat...Round_Rock.gif

If the monovalve is defective or not getting 12 volts to the coil you will have coolant flow through the heater core all the time.

__________________
Joe

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1980 300SD - 495k miles - 'The Ambassador'
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Former Family Members
95 C280
73 280SEL
90 300D
87 300SDL (X2)
86 560SEL
84 300D
80 300SD

Temp sensor?

Do you get high speed fan when you press the top button and low speed when you press the bottom one?

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Yes

__________________
-Randy Wakefield

1969 220D 4 speed (parts car)
1976 280C
1976 280S
1981 240D 4 speed (parts car)
1982 300D
1983 300TD (Ivory)
1983 300TD (gold)
1985 300TD (gray)
1987 190D 2.5
1970 280SEL (sold)
1977 240D 4 speed (sold)
1974 280 (rusted to death)
---
1927 Chevy 4 door sedan
1938 Chevy 2 door sedan
1950 Willys Jeepster
1955 Studebaker President 4 door
1977 Ford F250
1979 Glastron 17'
1948 John Deere A
1960 John Deere 2010
1979 Satoh S650G
--
2000 Bichon (Doby)