2006 Z4 electrical problem

[larrycad]

New to the forum, so be nice!
Wife has a 2006 Z4 convertible, automatic. I just installed a new battery, as I suspected the old one was bad. Apparently there is yet another problem, apparent at several levels.

Watching the battery voltage with the car not on, nor running, the 14VDC immediately begins to drop and within a minute it reads below 13VDC. If I let the car set in the garage overnight, the battery is almost drained. This is true for both the old and the new. (Old one was about 5 years)

With a newly charged new battery, the engine will turn over and start, but the top mechanism will not operate properly. Specifically, the latch mechanism motor will not rotate to lock or unlock the roof. If I repeatedly push either the "open" or "close" buttons, with a brief stop in between, I can get the roof to either lock, or unlock, but still no pump motor action, even with a new battery. Last time I drove it, (about two weeks ago), the roof worked fine.

I think I have two problems, one is the electric issue that drains the battery, and the second is the stubborn pump. The pump is capable of lifting and lowering the roof when i turn the motor by hand, and it turns easily. However, the latch mechanism won't turn properly, and the pump won't turn at all.

Is there an electrical schematic available for this car? (I have sufficient education and training to use a schematic)

Thanks,
Larry

Is there anyone here who has experienced anything like this? Any help would be appreciated.

[Our03z4]

Have you made sure the trunks upper deck didn't get raised or the safety switches aren't broken? That's usually the issue with that. The battery won't stay at the voltage, that's the charge from the alternator. It should settle to 12.6v, what does it settle at?

[wdb]

If you have something draining the battery that quickly, you might try pulling fuses. Loosen the negative terminal and lift it off, then touch it back to the battery, looking for a spark. Pull a fuse, look for spark, lather rinse repeat. If you have a ammeter you can put in line with the battery and terminal that will save you looking for sparks.

The top motors are notorious for getting wet and rusting. Do a visual check.

A code reader might be helpful too.

[charjo]

Had the same problem with "new to me" 2006 Z4. Compartment door between seats should have a plastic part extending down from hinge area of door that pushes a micro switch. Mine was broken off so light in compartment stayed on, draining the battery. Fix was to drill a pilot hole where the part would have been and insert a small round head screw that will hit the micro switch. Worked for me.

[javis20]

Since your draining the battery so quickly and the convertible top isn't working properly, could it be the salmon relays?

The relays are located next to the battery.

[javis20]

Well?