My '98 E320 developed a problem this week with the indoor fan. After starting the car, the a/c comes on and the indoor fan ramps up to only half speed. The climate control display shows that it should go up to 100% but it's not. Fan or climate control unit problems? How do I stand on my head under the dash to find the fan leads to test? Do these fans have speed resistors at the fan? Thanks in advance for the help!

I forgot to say when I first posted that:
The A/C blows cold
The fan does not ramp up to high speed when it is manually put to "high", it only stays on medium speed (which is the highest speed I'm getting out of it now).

 

I have a 1997 E320. When the blower is turned to MAX, it only blows medium. Another form said it could be the blower regulator which regulates the fan speed.