1997 BMW Z3 brake lights won't come on.
The brake lamp circuits on your 1997 BMW Z3 are pretty "old-school" and straight forward. Fuse #46 (15 Amp), located in the Front Power Distribution Box at the left rear side of the engine compartment supplies battery voltage to the brake light switch via the VIOLET/GREEN wire going into the switch. When the bake pedal is depressed, the voltage leaves the brake lamp switch on the BLUE/RED wire and supplies power to all of the brake lamp bulbs.
The brake lamp circuits do branch off and go to several control modules. This is ONLY for module INPUT to tell the module that the brakes are being applied. These modules include:
> Transmission Control Module
> Cruise Control Module
> ABS Control Module
> Slip Control Module
The ONLY way that any of these modules could be affecting the operation of your brake lamps is if there is an internal short to ground in the module that is causing the brake lamp fuse to blow.
If NONE of your brake lamps are working, the most likely causes are:
> Fuse #46 open (blown)
> Defective brake lamp switch
> Bad ground connection at ground G400 (Left side of luggage compartment)
> All 3 of your brake lamp bulbs burned out.
Yes, the BLUE/RED wire could be broken as well, but I would check all the other things listed above first.
Apr 24, 2012 |
1997 BMW Z3 Roadster