Changed the bulbs on my 2011 f150 because blinker and brake lights were out but it did not correct the problem, what else could it be ?
Check fuses, then if fuse is blown see if the bulb socket or those wires to them have shorts or insulation rubbed off touching metal or each other causing the fuse to blow, the brake light switch and blinker switch are in different places but the common is likely the fuse. Anything else on that fuse could be the issue too, like (do not have wiring diagram) Lighter socket, dome light, radio/stereo, accessory port, ect.
Checked fuse it looked fine....Is it possible that one of the headlight bulbs are bad. Also my husband had work done on left front end repaired ...New headlight and some other parts have been replaced.That is when the blinker started to blink very fast.Didn't notice brake light and blinker didn't work properly.Only blinker working was on outside driver window. My friends riding behind me said to go buy new bulbs because brake and blinker aren't working.I'm thinking it's electrical .
A lot of times blinking fast is either a bad flasher (under dash near or on fuse block) or a bad bulb. The work on front may have something to do with the blinkers and only to brake lights if it shares a fuse or ground. May check light grounds there and to lights not working. Brake light switch at brake pedal for brake lights. Check fuses under hood too. look for grounds wires to frame in rear, under truck. Locate that fuse and change it out to confirm its not bad.
Here is a quote from another page for a older model but possible for you too just may be in a different location, I would look under it real good and clean any connectors and look for bad wires. "Under the rear tire is a "T" connector, for the trailer hookup. Take it apart, clean the contacts, and put it back together, should fix the problem. (even if you do not have trailer wiring, the connector will still be there, just not a T)."
Probably a ground problem. Does it affect only one side of just the front or back? If hubby has a multi-meter checking is simple. Check the net for "checking light grounding problems on F-150" Nine out of ten times it's either be a ground wire broken/corroded or a break in the hot wire feeding the lights.
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