Convertible Top Does Not Open

[1998BMWZ3]

Hello everyone:

I own a 1998 Z3 which has an automatic push-button system to lower the leather top. Basically I just remove the hooks, push up the top a little & press the "down" button and it opens down.

Of late however the top just doen't open. Sometimes it works if I push down the top a lot and then press the button. But that isn't reliable. The thing that worries me, is that its totally random, sometimes it opens sometime it doesn't.

Has anybody had this problem with your convertibles? Any solutions?

Thanks for your help!!

[bryan1970]

do the motors run when you push the button or just nothing? i guess it could be a bad control switch, but it might be one of the microswitches on the top aren't being actuated and the car might think the top is in a diffrent position than it actually is.

[Dirty_Tool]

there is a microswitch on the left side of the top that commonly fails and it can be tested using a multimeter right at the control switch.
there are also relays back near the pump that fail and also sometimes the bleeder valve on the reservoir comes loose and wont allow hydraulic pressure to build up.
Poster, let us know what your mechanical/electrical abilties are and if you want help trying to troubleshoot this yourself, or if you only wanted ideas of common problems?

DT

[bryan1970]

i thought Z3 tops were like E36 and didn't have hydrolics??? are they more like E46 i guess

do the Z3's have anything similar to the rear deck lid on a Z4 that has to be up for the top to close?

[zuudbye]

My '96 Z3 is strictly manual and no rear deck lid thing, top just drops in the cutout in the passager compartment. Has a seperate boot to cover it all up.

[1998BMWZ3]

Thanks for your responses guys.

Looks like the motor doesn't run. It does make some sound when its up but now its dead & silent (well, most of the times).

But since it does work sometimes, I am guessing the motor is working fine but somehow its not getting activated. Also, as I mentioned, if I try different positions of the top, at some point the motor triggers and starts running.

I don't have much experience with electrical/mechanical maintenence but would like to give to give this a shot, unless it requires some special tools.

Regards.

[Dirty_Tool]

The first things I would check is fuses #1 and #46. Make sure they are ok. Also make sure that the brake lights are working fine when pressing the pedal. On the z3 you Do have to press the brake pedal in order for the top to work. If all that checks out OK then i suggest testing the microswitch for the top positioning. You will need a multimeter, so if you dont have 1 maybe you can borrow 1.
Put the meter on the ohm setting for testing resistance. Remove the switch for the convertible top and disconnect it. At the connector that the switch plugs into put 1 lead of the meter to pin #2 and connect the other lead to body ground. With the top up and the latch released (basically in the position which you would normally press the button to lower the top) you should have continuity to ground. The meter should have a reading less than 1 ohm. If you have high resistance or an open circuit then that means that the microswitch is faulty and needs to be replaced. It comes with its own new harness. If the reading is within spec but the top still doesnt work, then the problem may lie in the relays or the switch or somewhere else. Do these checks that I recommended 1st and then let us know how it turns out. Microswitches are a common failure, if I had to guess that would be my guess. Good luck and happy testing,
DT

[ZeeMe]

I have a 99 Z3 with the power top, and when you push open the top make sure you push down on the brake pedal and hold it,before you trigger the top down switch. I found that out the hard way. Opens every time now.

[1998BMWZ3]

I am having a tough time removing the switch for the top and disconnecting it. I guess I will consult a mechanic. Will let you guys know what I find.