RF2

Spliced from pin 87 on relay to X210. Even used a brown wire. Fan works on all speeds. Life is good.

Oldblue

Bingo! The brown wire! Now to find out where it was broken and why.

tim597

Check the brown wire from x210 to the blower. On my 2010, the wire was pinched from the factory grey wire wrap right behind the motor.

RF2

The wire from pin 87 on the back of the fuse box had come off. Re soldered it back on. All is well now.

Oldblue

Just not the blue wire, Riggs!!!!

David.Lister

So what's the easiest way to get to the back of the inside fuse panel?

Background:
I'm having a similar issue as the OP... Only I'm measuring a not-infinite-but-high resistance (~megaohms) between the front of Relay 30's pin 87 and the X210 connector's brown wire. Because the contact isn't completely gone, when I check voltage with the blower unplugged (open circuit), the wires that would be feeding the blower actually seem to be supplying a misleadingly decent battery voltage; but when a small load is applied (10 ohm) I can only draw a few milliamps of current due to the high resistance somewhere between the relay and X210, and the blower doesn't turn. Ground side is good, with only whatever small resistance is selected by the speed control.
(BTW, I bench tested the relay too. Applying 12V from a wifi router DC power supply open/closes contacts with solid action and negligible resistance through the relay).

So how do I get to the back of pin 87's socket?

donbrew

Then you don't have a similar problem as the OP.

Does the fan work if you jump 30 to 87? Does that blow the fuse? What about resistance of the motor? Does the motor turn by hand?

What exactly is happening?

To answer your question: remove the bolt holding the BCM.

Are you sure you are testing 87?

David.Lister

Thanks. Got it. Found my loose connection.
--

For completeness then:
The blower motor 's resistance is about 3.5 ohms.
The motor turns freely and would blow strong when connected directly to the battery, but not when fed from the BCM.
The connector to the blower appeared to be supplying >12 V (when unplugged from the blower motor). However, when the blower was actually plugged in, there was very little voltage across the motor and very little current being drawn, and the blower did not appear to be turning.

Jumping pins 30 & 87 produced the same effect as having the relay in, i.e. 12 volts at the (unplugged) blower motor connector, but very little voltage across the motor with the blower actually plugged in. Fuses all good. Was measuring a large resistance between pin 27 and connector X210. (Yes, it's pin 27).
I found my bad connection while working to get to the back of the BCM.
Blower now working at all speeds. Thanks.

Oldblue

Awesome, loose connections, always first place to look.


Riggs, on three?