Front left bulb, and mirror bulb not flashing. Both of those bulbs are new. Rear bulbs are both flashing fast. Dash light also flashing fast. Multimeter shows they are grounded. Is there a common problem to look at? 09 f150 FX4

 

On what? Can't see your vehicle through the Internet.

 

Most likely, the BCM found something it didn't like so it disabled that circuit. You will need to scan the BCM for fault codes. There aren't really any shortcuts beyond swapping the bulbs. Do make sure you don;t have multiple bad bulbs, regardless of age. Wouldn't be the first time that has happened. Alternatively, there is an open circuit in the feed from the BCM to the first splice in the circuit.

And, no, before anyone throws it out there, it is not possible for the multi-function switch to cause this.

 

Thanks for the info, I'll have to have it scanned by a better scanner than what I have in my little handheld scanner.

 

Forscan can read BCM codes and do a lot of other things.

https://forscan.org/home.html

 

It acted up a few months ago, but then it would flash the front bulb one time as soon as you push down on the lever, and then start blinking the rear fast, it wouldn't blink the front at all. I would just bounce the lever constantly if I needed the left turn, knowing the front bulb was flashing each time. Then out of the blue it started working again. I'm sure it's the same problem just escalated

 

you can check the rear lights to see what bulbs are installed, LEDs without load resister will hyper flash and front signal lights wont work.