all lights work but one running light (the drivers side tail light) I replaced the bulb. No help. Fi50 95
remove the bulb from the socket and use a multi-meter to check for 12 volts inside the socket. If not present, use the pointed probe to pierce the insulation on the wire a couple of inches back from the socket. If still not present, keep checking backward for the fault. Current is usually supplied to one side tail light, and a jumper is used to connect the other side. Check the jumper for presence of 12 volts.
Thank you OJ
Search Ford F-150 Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Ford F-150 Experts