This is a really weird problem. On a 1997 F-150 with no Auto Headlights and no Day Time Running Lights, the right low beam refuses to work. After replacing the bulb and connector, it still will not work. Using a voltmeter, there is 11-12 volts getting to the headlight connector when the headlights are on, 0-1v on the high beam side. When the high beams are turned on, it reverses and all this is normal. So then you would think the bulb is bad, but it works fine in the left side headlight. The right side harness was replaced and wires spliced, but all connections check out ok, and if the harness leads are connected to an outside 12v source, all works fine with the bulb so the bulb/harness connections are good. So since there is power there, and the bulb is good, what on earth would prevent the low beam from lighting up on the truck. This has many people very stumped and frustrated. Any ideas?

 

StS53,

I would make sure the right Side was the same as the left side. Use your volt meter and measure the voltage from each terminal on each Left and right connector both high and low beams and off. If they are not the same check the wiring connections you made.

Hope this helps.

 

Try checking the connection tabs - they might be dirty. Try Checking the voltage at the connection....no the plug, but the actual contact point.

Robbie