Good day, thank you for your help. Last weekend was sunny and clear so I took my chance and dismantled the instrument cluster as advised, found two connectors on the back side of the cluster and carefully cleaned those using a tooth brush and a dielectric spay (I used a Liqui Moly electric contact cleaner spay). After cleaning, I used a disposable syringe needle to unbend the socket pins in the two connectors to make them tighter a tad and ensure better contacts between the connectors and the instrument panel. I also got under my jeep, disconnected a speed sensor (located on the back of a transfer case) and cleaned contacts in the connector plug the same way I did to the instrument cluster connectors. Plugged everything back and the problem was gone. But, now my speedometer seems lagging a bit, meaning it is not up to my acceleration tempo by ca. 5 miles maybe, and I think whatever was an original problem, my speed sensor has reached the end of its service life and now needs to be replaced.
Monday, November 11th, 2019 AT 7:23 PM