W124 300D no power at climate switches
 

How's it going all, been a while. Car has been running fine, but an issue has come up I never dealt with before.
At first the heat would not come on till the motor warmed up. I didn't try the defroster, so I don't know if it was working. The blower would come on later and later, and now does not come on at all. The fuse is fine, so where would be the next place to look? Do these 124's have a thermostat that would control the power to the blower? Any ideas before I pull the dash apart? Thanks

There’s a yellow signal wire to the blower controller at a junction above the brake booster. Set the ACC to defrost and check voltage at the yellow wire. Check voltage at the bigger wires as well. One should be constant 12V the other is ground. The yellow wire sends 0-7V or something like that to the blower controller under the blower. It should register 7V or so on defrost.

Sixto
98 E320s sedan and wagon