I tried the following:
1. I made a strap between the two connector on the sensor to see if there is any light on the dashboard. Nothing!
2. I squeezed the connectors with pliers to have more pressure for contact on the sensors. Nothing!
3. I tried to tighten the sensor with about 1/4 but I was not able to do it. It is in an impossible position! Nothing happened!

I left out of neutral lights running on the road. Nothing unusual! What can I do more? Thanks!

 

Replace it?

 

replace the bulb

 

I sprayed some WD40 inside the bulb and it worked for about a day. Than again...
Final decision: replaced already.

Have a great ride!