You have high fan when jumping 30-87 and this is the load side of the K-9 relay, so the coil side of the relay is not pulling in or you have a bad relay.

You know you have power as the load fuse feeds both high/low speed fan. So the test is to ground br/gn wire at pin #2 at temp sensor for 105 cut-in. This completes coil side circuit for relay latch.
If high speed now comes on, change ETC sensor.

If it does not , you have a bad relay/open wire.....

I can send you the schematic , if needed