Saturday night my "you have a light out" light comes on...or whatever that things called. I try the right signals, everythings fine. Try the left and I get the fast blinking on the dash. When I get home I hit the left one again, and get out to check which light is out. The front lights working. I go around back to check the rear signals. Not only is it not out, it's blinking. But, the right signal is also blinking on and off along with the tag lights. Looked like I had my hazard lights on. I turned the truck off and go inside. I went out later Saturday night and it didn't do it that time. The light is off now, but has come on again on the dash. I did notice that the right signal light did look a little dimmer than the left one. Any ideas? Thanks.

 

What year is the truck?

 

What has the weather been like recently? Sounds suspiciously like a flasher relay/control box short out. Your truck will think that a light is out if too many lights are activated due to a short because the resistance is out of expected ranges. The only place I can think of that could cause a reaction between the left, right AND tag lights would be in the fuse box/flasher relay box. Check your fuse box first.

 

i have also seen this problem, due to a bad ground at the light (just not on a dak) if the ground isnt making good connection, it can back feed through other light trying to find ground, and it will light up the other lights just not to full brightness... just a thought

 

Truck is an 05. It's been dry lately. I thought it might be ground to. Because of the one light not being as bright as the other. I've replaced one of the tail lights in the last couple of months. Don't remember which one. I wasn't sure if it was just the new bulb looking brighter. Where could the ground be?

 

some times a filiment brakes and falls onto the other filiment and makes strange things happen.