I hope this is in the right section to ask so here goes. I have a 99 Z34 with the usual multifunction switch problem. I haven't replaced the switch yet but I will soon. Now Im having problems with the brake lights going out during rain. The third light works fine. When this happens the ABS is affected also,
because I can feel it when trying to stop. On another forum a member said to check wires in the column but that would be a constant problem not just when raining. After the roads dry out the body brake lights work fine ABS works. Im at a loss. Any ideas on where to start looking? Came close to getting rearended the other morning going to work. Would the BCM have anything to do with this? Location of BCM? Im a newby to this forum seeking help from the masses. All info is greatly appreciated. Muleteam

the diagrams dont show any interaction with BCM. the rear lights go through the turn signal, but the center does not. so unless the turn signal is shorting it out i dont think thats the primary issue. i would look at the rear housings and see if they are water tight or retaining water

Sir, are you referring to the brake light housings? If so, no they aren't holding moisture at all. Could a not watertight connection at the ABS switches be a long shot? This car has not been "butchered" by a PO because he is my brother. He is too to do anything not perfect. I appreciate your reply jwfirebird. If the weather is decent this wknd ill get under the car. Thanks again. Muley

could try a couple things, disconnect the abs and put the connector in a bag or just tape it up then drive it and see. or you could squirt everything down with water while someone is watching the lights and put a brick on the petal or something