I am need some help trying to find out the fix to the following problem: Before anyone ask, I have replaced the brake light switch, but it did not help. I have also checked all the fuses and all a fine.

Car is a 1999 Mazda 626 v6.

Problem: When the parking lights/head lights are turned on, the brake light in the back windows stay on all the time. Also when the lights are turned on, the cruise control doesn't work. When the lights are turned off, the brake lights work find except that when you hit the brake light, the two sigh FRONT flashers (yellow lights) come on when you hit the brakes (very strange). Also when the lights are turned off, the back brake light works fine.


Any suggestions on what may be causing this proble? Should I just go ahead and take it to the dealer?

Stephen

 

Sure sounds like a bulb problem in the back. The rear light bulbs have dual elements, and can cause this. Have the bulbs been replaced recently? If so, make sure there is not a single element bulb in a dual element socket. I have also seen where one filament in the bulb burns out BUT shorts out to the other element in the same bulb causing voltage to feedback through the system. All lights will appear to work normally even though one element is burned out. The vehicle computer thinks the brakes are applied (when they really are not) not allowing cruise control to work. Easiest way to check is to turn the lights on while duplicating the problem and remove bulbs one at a time and see if the center brake light goes off. If so, then you found the bad bulb.

 

Well, that was it...I can't believe it. You saved me!

I was really worried that it was something much more difficult and electrical than that. Now that you pointed it out to me, I turned on the lights and noticed that there was one bulb that was out. Replaced it and now everything works. It seems to me that if just one bulb had gone bad it would just stay out, not effect the entire system!

Thanks for you help. I don't know very much about cars, as you can tell, and this was very helpful. I really learned something. I was getting ready to be ripped off at the Mazda dealership.

Thanks,
Stephen

 

COOL! You got it fixed, it usually turns out to be something simple! All it cost was some new bulbs.