03 Z4, Roof wont unlatch / red light blinking

B

BMAD

Member
Hi folks,

I have read tons of posts about the micro-switch, the red hydraulic disabling switch, the drains, the rear left hydraulic motor, the trunk rack being in low position, manual opening and whatnot. But my problem is that I can't even get my roof to unlatch from its closed position. Now i realize this is ideal to it being stuck open, but I still want to operate my top, here are my specifics:

Top was working fine today, I got in and went down a few blocks, came to a stop and decided to drop the roof, the windows went down halfway, the front motor made the typical noise to unlatch...but then nothing happened. I tried pressing it again and nothing, now I am dealing with a permanent red blinking light, I tried initiating the closing sequence thinking it would reset something and allow it to reopen, and it will whirl and the motor will then loudly squeal but the red blinking light remains.

I am not sure what the problem is, most people have the top unlatch and then it wont go down, or its down and it wont go up, but i couldnt find any posts of somebody with their top failing to unlatch. I opened the center panel in the top and fiddled around with the hex key but nothing seemed to loosen/unlatch and I felt like I was going to just make it worse so I left it alone.

Some sensor or something failing to engage is all I can think of but I have no idea where to begin the diagnosis.

Anyone have an idea?

Thanks,

Bob
 
Follow-up, it worked the next morning just fine! Then that evening it wouldnt lower again. Is there some setting that stops the top from going down at night? I have read the thermostat can affect this, but my car reads the outside temp accurately and this is 75+ degree weather...I am confused how this is occurring.
 
Hi Bob, welcome to the forum - quite a few members on here can advise you; just that there are only a few of us active at the moment and I'm not one of them in the know. I guess from the temp that you're not in the UK though as here you're never too far away from help.

How about posting some pics of your Zed (its a forum thing!) and sunshine (its almost autumn here and the days are starting to get shorter and cooler already) while you wait for a roof expert to come along.
 
Hey thanks for the reply, here's my Z.
 

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It’s certainly not thermostat or night time related! If the unlatch motor is operating but its not physically unlatching it could just be the latches need greasing. If you can get it open again make sure to apply some grease on the latch points.
 
ph001 said:
It’s certainly not thermostat or night time related! If the unlatch motor is operating but its not physically unlatching it could just be the latches need greasing. If you can get it open again make sure to apply some grease on the latch points.
Click to expand...

But it works everyday with no problems. It simply doesnt work at night! lol This is the weirdest thing ive ever dealt with, it's as if there is a PM-Disabling button. 11PM rolls around and it wont go down, but next morning I leave for work, it goes up and down just fine.
 
Just as an experiment I went ahead and kept the top down before nightfall. Now it is down and wont go up at night either lol. It is the latch, it simply wont unlatch at night, this is the oddest situation.
 
What sort of ambient temperature differentials are you experiencing between night and day where you live? I wonder if the cooler / warmer temperatures are affecting the alignment of the catches somehow. Have you greased the contact points as mentioned before?
 
... this is what gives these cars such character.

I never had this issue with my old E85, though I did keep it mainly garaged, cleaned drains & tried to squirt the odd bit of WD40, not sure if it ever hit anything but must have just been lucky

Hope u find the fix soon
 
ph001 said:
What sort of ambient temperature differentials are you experiencing between night and day where you live? I wonder if the cooler / warmer temperatures are affecting the alignment of the catches somehow. Have you greased the contact points as mentioned before?
Click to expand...
I live in California, it ranges from 70* to 96* right now, it cant be because its too cold. I cant see it being a need for lubricant as everything works perfect in the day. The motor runs, the latches simply wont disengage, though i hear it seeming to try.

I am going to try one more experiment tomorrow with leaving the top 90% closed without latching and seeing if it will close and latch itself.
 
BMAD said:
The motor runs, the latches simply wont disengage, though i hear it seeming to try
Click to expand...

..at the risk of repeating the above, that sounds exactly like the conical pins sticking in the holes. It's important that both these areas are well lubed. Use a thick grease on the conical pins and a good quality spray grease on the black latches.

roof latch 1.jpg
roof latch 2.jpg
 
You can see how the latch mechanism is operated on this image. There is a single motor in the centre that operates both latch mechanisms via a flexi coupling...

roof latch 3.jpg
 
This You tube video describes how it works and how to access the motor. Maybe you have a gearbox issue as suggested in the video but I wouldn't really expect that to work sometimes and not others....

https://www.youtube.com/watch?v=otCbHnwZ-Ig
 
Update: I work a PM shift at a hospital so I am not usually driving this Z in the early morning hours. My wife took it to the gym this morning, top wouldn't up up until 9:12AM PST. This really feels like a computer/setting issue, if the motor was weak it wouldn't suddenly begin working right? It doesn't go up sluggish or weak, it either goes up normal or it simply doesn't unlatch despite hearing the hydraulic motor trying to work. I am going to see if it stops working around 9PM tonight, I am not sure but i suppose I just want a better picture of what i'm dealing with prior to going to dealer. I cant justify replacing any motors or top when they work just fine during the day.
 
As a final suggestion, could it be related to the battery state of charge? There have certainly been cases of roofs not working properly with a dying battery. If you are certain it's not a gearbox or lubrication issue I would defo be considering a new battery.

There is no way this can be a computer / setting issue.
 
I had considered the battery, but it seemed so unlikely that the battery would be too weak to work the top all night and then be able to operate it come morning without any driving or charging performed. Maybe its some sort of short somewhere mixed with a nighttime setting?
 
I really think you are over-complicating it. Remove that plastic panel at the front of the roof to expose the latch motor. If the motor and flexi couplings are turning when you try and open the roof but it's not unlatching then it's a mechanical problem with the latch mechanism. Note there are limit switches at each end of the worm gear, so perhaps these have failed or come out of alignment so the motor doesn't know where it is?
 
Other option might be a cable break under the hood. This is not uncommon and it might throw the computer off, if the hall sensor data does not change.

If you have access to INPA, check what your roof module reads when its fully locked and when you unlock.
 
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