Hi everyone!

I need some help solving a brake light problem I am having. My brake lights flash on and off while I'm driving or really anytime the truck is running.
After reading a few posts I thought I would try replacing the PDC, so I ordered one from the dealer with the new splash guard.

Well brake lights still flashing on and off.......... so I thought ok now lets try replacing the FCM. I did and problem still not solved. So I thought maybe the brake pedal switch, I have not done this yet because I don't think that will fix it either. The reason I say that is I can hear a clicking in the dash every time the brakes flash on and off. Maybe something in the dash???

Any ideas would be greatly appreciated.

Ron

 

The brake switch is the first place i would have started. If its got faulty terminals it could intermittently cause the brake light circuit to energize.

One way to find out, get up to 40mph and set the cruise control. If the cruise control either wont set at all, or if it deactivates like you hit the brakes, then the brake switch is the culprit since it controls not only the brake lights, but the cruise control as well.

If the cruise is unaffected, but the lights continue to flash, then you have something in either the brake light circuit or the emergency flasher circuit thats causing them to light.

 

Thank you for the response, I'll try the cruise like you said, but i've never had a problem with it. And yes I prob should have started with the switch. I may order a switch today anyway.

 

After talking it over with another tech, the brake switch may be a dual contact switch, meaning it has one contact for the cruise and another for the lights, so if the cruise test doesnt work then dont rule it out completely...

 

I just checked oreilly auto and they have a switch. I'll go get one and replace it today. I'll let you know if this works. Thanks for your input.

And FYI Dauphin Island is one of my favorite places, love it down there.

 

Well I replaced the brake light switch today and so far no problems, I need to drive it a few more days before I say it's fixed.

My replacing the PDC first started when i took my truck to a repair shop to have them tell me what was going on with the brake lights. And this shop is very popular around here and always busy. I dropped my truck off at seven thirty in the morning and was told they have a Dodge tech they just hired who was very familiar with these type issues and I should have a answer in a couple hours. Now it's four in the afternoon and still no call from them, so I call they say "well it looks like the PDC has gone bad from water damage and will need to be replaced looking around 800 dollars" no thank you I say I'll be down to pick up my truck.

So I ordered one from the dealer, little under four hundred dollars. Thinking this would fix this and save the rip off charges from the shop.
Didn't fix it, so my next thought was ok... replace the FCM, maybe that will do it. Another two hundred dollars. And still no fix.

That brings me to today, after three weeks and seven hundred dollars, a thirteen dollar part and five minutes labor may have fixed it.
Never again will I trust the "local shop with the new hire Dodge tech"
I will do my research here or wherever I can and try to fix myself.

Sorry for the long post just venting, but I do love my truck and the money was well spent knowing I'm good for another hundred thousand miles.
I hope.

 

I'm not sure how they came to that diagnosis in the first place. Either way, glad you got it fixed.