Simplest from 75 or X is a load reduction circuit, its on when car is on or running and goes off when the stater Terminal 50 is actived to allow more power for engine starting. Not an issue seeing you said you had power at the plug connector to blower motor.
Okay, I got NO light when I hooked test light to positive battery and touched the C11 lead (ground) while it was hooked up to the back of the E87. Does that mean I have another bad E87? (Verified test light was working by touching a chassis ground.)
Thanks for your help
Starter Motor Exciter
No it is not. Hopefully I didn't fry anything. I verified the harness is okay, so it must be a problem with either the E87 or the J126. I don't know how to test the J126 by itself (or the E87). But I did try a new J126 and the fan still does not work - so I don't think the issue is with the J126. I swapped the E87 with a used one, and it behaved the same: fan speed indicator display rose and fell repeatedly with a period of a couple seconds, and fan did not work. I understand that when T50 is energized to start the car, the fan won't get 12V.
How - Because you don't say !
Cancel that - Waste of time and money !!
You have no clue how that blower works !!