Heat Blowing but not Hot Air; Warm then Cool; 78 450SL - PeachParts Mercedes-Benz Forum

jnanasakti · #1 03-19-2011, 10:23 PM

The heat used to work fine on my car, then it stopped blowing hot air.

I replaced one vacuum check valve, but don't see anything eelse obvious.

Any ideas based on Warm air then cooler on the DEF position?

meltedpanda · #2 03-20-2011, 12:40 PM

I believe you have the ACC II system , in which case it could be the servo itself, the square box thing along the firewall, unfortunately , not easy to repair

jnanasakti · #3 03-20-2011, 09:39 PM

Are you talking about the Climate Control Amplifier? I attached a pic from off the net.

Or, there is the AC & Heater Control Valve; which is more like a servo I think.

Quote:

Originally Posted by meltedpanda

I believe you have the ACC II system , in which case it could be the servo itself, the square box thing along the firewall, unfortunately , not easy to repair

meltedpanda · #4 03-21-2011, 10:54 AM

If you have one of these, it is most likely your issue, assuming you have ruled out the obvious - like disconnected, broken lines , and flaps
ACCII Climate Servo: 102 or 104

jnanasakti · #5 03-21-2011, 03:07 PM

I see now. Not easy to repair and it seems very costly to replace too. Thanks for the info.

meltedpanda · #6 03-21-2011, 08:26 PM

there are after market servos, not bad at just under $400, really have no option if you want your ACC to work, you can bypass but it only used if it is leaking

thorsen · #7 03-21-2011, 10:10 PM

I replaced mine with the UnwiredTools.com kit and am very pleased with it. What part of Chicago are you in?

jnanasakti · #8 06-20-2011, 02:24 PM

Apologies...haven't been on the forum in a while (been working on my car!!). I live in Roscoe Village; west Lakeview, near Ashland and Belmont. Do you live in Chicago?

Quote:

Originally Posted by thorsen

I replaced mine with the UnwiredTools.com kit and am very pleased with it. What part of Chicago are you in?