E39 Headlights dim when I press the brakes

Oct 05, 2007 5 Replies

Hello,



I have a 2000 E39.



Tonight when I started the car, the "Service engine soon" light was illuminated. The car seemed to be running fine. I started to notice though when my foot hits the brake pedal the headlights will dim. It seem to get more noticeable later.



What could be the problem?



Thanks, Jeff


The Check Engine light means the computer has detected a problem and stored a code. You need to find out what the code is.

Your car is OBD II (on board diagnostics, level 2) compliant. This means you can buy a code reader at virtually any auto parts store for about the same price as paying BMW to plug in the reader they have and pull the codes for you, OR you can ask them at AutoZone to pull the codes or let you use the scan tool and pull the codes yourself. AutoZone does this for free.

Lights dimming when you press the brakes sounds like the alternator isn't charging properly.

More likely to be a wiring problem.

You might check your charging system and your battery it might have lose connections/if it was the alternator it would do it when you turned on or off any electrical appliance....

Nahh - if things were that bad he never start the beast. It will likely be corrosion on one of the light units

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