So I've been having issues with my ABS and Parking Brake lights coming on only when I have my headlights turned on. I tried something new tonight and got a weird result. Usually I'll click on my headlights in the carport and immediately the ABS and Parking Brake lights illuminate. Reading post after post after post that this was due to the speed sensor I dismissed my speed sensor as the problem because my speedo works just fine. Thinking it still might be a problem back there I left the carport with no headlights tonight. I got up to speed on the road and switched them on. No ABS and Parking Brake lights came on!!! WOOHOO!!! Then I stopped at the stop sign. I could feel a clicking in my brake pedal. I became concerned right away. After four clicks my ABS and Parking Brake lights came on and the clicking stopped. WTF? Anyone have any ideas?

 

yeah i am gonna have to say speed sensor. Now what is throwing you off is that the speed sensor is not what runs the speedometer. That comes off the transmission.
The speed sensor is in the rear axle, and determines if the rear tires are locked up or not. If they are, it tells the ABS system to release the brake on the locked up tire. The 'clicking' you hear and feel is the ABS system releasing the brake that is supposedly locked up.
The headlights dont have anything to do with the problem.

 

But why is it only happening when I turn the headlights on??? If I leave the headlights off everything is fine.

 

i really dont think there is a correlation between the two. However, a easy and fun fix would be to drive with night vision goggles on!

 

I know.... That's why I'm confused. Night vision goggles would be awesome.