I will be just happy to feel regualer air from these vents.1994 s420

[henboy1]

Fan stopped blowing air in the vents.I then changed the fan motor. Then changed the resistor.Still no air, so, I changed the HVAC climate unit.No air , but air comes on when the ignition is on #1(radio ).It also comes on when doing diags.
From the dtc pdf manual it says to do diag ....
Press .REST
memory. Continue to press the left and right buttons until all DTC's
Within 20 seconds simultaneously press EC and 0 for 2 sec.This is when the fan turns on with a code 01 on the left screen.
Someone mentioned having to program each HVAC unit for each car.Any help please

 

[emerydc8]

Fan stopped blowing air in the vents.I then changed the fan motor. Then changed the resistor.Still no air, so, I changed the HVAC climate unit.No air , but air comes on when the ignition is on #1(radio ).

Check the strip fuse in front of the brake booster. The fuse can be cracked and still look good.

If the fan will work with the ignition switch in the #1 position, I would look into changing the ignition switch. I just went through this. The tab inside the rotary switch broke off. Power to the fan motor (through the regulator) runs through the ignition switch.

 

[henboy1]

Great info.Will check and report

 

[nocfn]

The PBU can also be bad, if you have a spare - give that a try. You can also TEST (a nasty 4 letter word) the voltage coming from the PBU wiring at the firewall going to the resistor/fan as well.

 

[gerryvz]

Since you have an S-class (W140), and this is a W124 forum, it is very likely that you will be challenged to get an answer on this site. This is because the W124 and W140 ACC systems are VERY VERY different in concept and execution. I recommend one of the W140-specific forums like the one on Benzworld.org.

Moving this thread to Off-Topic Discussions.

 

[henboy1]

The PBU can also be bad, if you have a spare - give that a try. You can also TEST (a nasty 4 letter word) the voltage coming from the PBU wiring at the firewall going to the resistor/fan as well.

what is a PBU?

 

[henboy1]

Since you have an S-class (W140), and this is a W124 forum, it is very likely that you will be challenged to get an answer on this site. This is because the W124 and W140 ACC systems are VERY VERY different in concept and execution. I recommend one of the W140-specific forums like the one on Benzworld.org.

Moving this thread to Off-Topic Discussions.

True.They are not as knowledgeable as this site

 

[gerryvz]

what is a PBU?

Push Button Unit. I don't know if this is applicable to a W140 car, as it uses an electronically controlled system, whereas the W124 PBU is a mechanical/electrical hybrid of a different design than the W140.

 

[nocfn]

YEP I did not catch that we were talking about W140 as an "e500e enthusiast" moniker.......