E420 Blower Speed/ Fault Code B1422
 

Hello All,
If anyone can help with this problem, will appreciate it.

Have production 9/97 E420 on which the blower fan works in all speeds engine off, key on.

But when the engine is running, there is no high speed blower fan.

Pulled fault code B1422 serial interface K1 from cluster to AC push button.

Any ideas?


Thanks all,
Aboantar.

B1422
Power Window RR Motor Circuit Failure

I wouldn't worry about that code. Set your panel to actual values (archives) and look to the blower regulator control voltage. Watch and see if it changes when the situation changes. If the voltage stays the same, look for a voltage drop on the power feed circuit.