The test are made at the 3 wire connector behind the brake booster......Rd/Bk/Yl

R to B -12V
Y to B - 2-8 V , depending on fan setting.

If No R to B , feed is bad .. [ fuse /ign sw]

If Y to B is NO, then CCP is bad or fuse for panel.

If both test are YES , then the reg is bad or brushes in motor are going.

Test for motor is to ground the blu wire ...that gives full fan
If NO , motor is bad ..if Yes , reg is not grounding/regulating b/c it is bad or is not getting trigger variable V from Panel [ yl wire]

__________________
A Dalton