Exterior Lights misteriously stop working

[LHirshman]

My truck is a 2005 quad cab.

Two weeks ago I drove my truck and all is well. Today I start it and the "lamp out" indicator lights. I figured a bulb. Well the front left and right turn signals don't light. The front parking lights don't light. The only lights on the front that work are the right low beam and left high beam. The rear brake lights work. The reverse lights work. Only the right turn signal and one bulb on the right parking light works. I did not check the fog lights.

I checked fuses, they look good. Is it possible all these bulbs went at once or is there some other cause?

Where do I start? I am familiar with electronics being an engineer. Help I'm stumped!

 

[Yo Hoot]

Sounds like the switch. Others who had the same issue can chime in.

Replacing it is easy. Just pop out the module that the switch is mounted in.

This is more in depth with diagnosis

 

[LHirshman]

Thank you. The symptoms, in the video, fit my problem exactly. When you wrote, switch, did you mean, the power module shown in the video?

 

[Yo Hoot]

Thank you. The symptoms, in the video, fit my problem exactly. When you wrote, switch, did you mean, the power module shown in the video?

The switch you use to turn on the headlights. My 04 it's on the left under the vent.

 

[LHirshman]

Will check it out, thanks.

 

[Ozymandias]

Will check it out, thanks.

If you disconnect the switch - the lights will be ON by default as soon as you start the engine. It's a fail safe measure.

 

[seafish]

This is more in depth with diagnosis

What a GREAT diagnostic video !!

Did you make that ??

 

[LHirshman]

Hi everyone. Today I was able to get the Power Module out of the truck. It is not hard once you figure it out.
Once out, I was able to see parts of the PC board inside. You can see the corroded trace thru one of the holes
in the housing. It is exactly in the same spot shown in the YouTube video posted by, Yo Hoot.

I will be attempting the repair this week. Stay tuned.

 

[LHirshman]

I opened the power module. Just like in the video the copper trace is gone. The picture is taken after I cleaned up the PC Board.
Judging from J64's connection, there is a lot of current flowing through that trace.

The board is conformal coated, which over time and heat at that spot, flaked off. The oxidation of the copper ensued resulting in failure.
My guess is, the vias (connecting holes) by J64 and in the cleaned area had a connection on the other side of the board.
Which may have failed some time ago precipitating the failure seen in the photo.

Since I design PC Boards for my job, my opinion is this was a bad design from the get go.

The power module is now repaired. I will reinstall it and (fingers crossed) my lights will work again.