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Discussion Starter · #1 · (Edited)
I just learned that my car has a hydraulic pump for the convertible top mounted in the trunk area and if the fluid is low, the top will stop working. Some people say it's a closed system and that would be hard, but maybe ? I have already checked my brake lights and they work so the brake light switch should be fine if it works with the convertible top ? The doors are closed, the handbrake on, the windows slightly down and I lift the top 8+ inches...but still nothing. So, I'm thinking switch or pump. Anyone with help as to how to diagnose which one ? I can grab the multimeter and start testing terminals and take a guess, but can anyone else offer any simpler ideas since I am working alone ? Thanks.

According to a very cool mechanic. Could be the micro switch that run from the first fold on the driver's side up top to the base of the top (the bottom hinge area). Trying to get to the switch under that plastic cap..any ideas ?



Optional Information:
Year: 2001
Make: BMW
Model: Z3 Roadster
Engine: 3.0

Already Tried:
Removing and fiddling with the switch, checked connections at the switch, moved convertible top higher, checked the brake lights to make sure they were working, dropped window down a little bit, closed the doors and checked fuses #1 and #46 and had continuity between them...
 

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I highly approve, your car is a twin to mine.

The brake switch on the pedal arm might be bad. I had that problem on an E34 I had. The brake lights worked fine but it still lit up a check control light.

Does your cruise control work?
 

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Discussion Starter · #3 ·
Thanks twin.

It worked this morning and now that I am messing around with the micro switch in the main area of the convertible hinge, the brake lights don't work now. The fuse is great....how do I test the brake switch ? Wait, let me check the forums first...
 

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It worked this morning and now that I am messing around with the micro switch in the main area of the convertible hinge, the brake lights don't work now. The fuse is great....how do I test the brake switch ? Wait, let me check the forums first...
One indication of your brake switch being bad is, your cruise control may not function properly. At least, that's happened to me in the past.
 

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Discussion Starter · #5 ·
Hey Doc

It wound out to be both the top micro switch and the brake light switch both went out...what are the chances of that. That micro switch is expensive...holy cow!

Speaking of...does anyone know of a good place to get this part number at decent price ? 54 34 8 407 250
 

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Discussion Starter · #7 ·
Great price

ordered mine finally for about $95....the labor that I saved made me feel better in buying it. When I get a chance, I will post a "how to" for diagnosing the convertible top problem and the brake light issue. Thanks everyone.
 

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If installing a new switch, it's easy, remove the cover plate remove the switch, trace the wire rearward into the dvr's side B piller, being carefull not to rip the rubber around the top mounting area, unplug the old switch...... reverse to install. I spliced in a used switch....
 
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