Diagnose fan/temp relay

[mrt6644]

Hello.  Ive been through countless threads and can't seem to get this straight.
I have a 95 K75 and I want to get the fan working as it is supposed to when new.

I replaced the fan so I know it's working.

I am using the oem relay and wiring.

What is going on is that the fan turns on right when the engine starts and stays that way.
I am trying to figure out how the relay is supposed to work.

I know that power goes to pin 15, ground to 31.
I know what A2 and A3 are for.

What I don't get is the triggering.  Originally I thought the the fan relay was triggered by low resistance to pin E.
However, it seems that the relay only triggers with 12+ volts to pin 9.

Which doesn't make sense as power on Pin 9 is always on right?

Ive tried applying ground to E, nothing.

What am I getting wrong?

[frankenduck]

When E resistance to ground goes down into the 150-200 ohm range the temp relay shorts 15 to A2 to power the fan. 9 powers the temp relay.

[mrt6644]

I was testing by putting e to ground and no dice.  Is ground too
Low resistance for this?
I was testing the relay with a power supply and I might have fried it

[Laitch]

From your description of the Brick, it could have been damaged before it came to you or it just could have failed from old age. Beemer Boneyard has a used one and there a couple of used ones on eBay.

[mrt6644]

Yeah, I was thinking g the relay is damaged and I damaged it worse.
If the resistance to E is brought down close to 1 ohm or a direct connection, does that still trigger the fan?

[frankenduck]

If E resistance gets really low or grounds then it should trigger both the fan and the overheat light in the luster.

[mrt6644]

So then the relay was probably damaged. I ordered a used one from Beemer boneyard
Thanks