Roof Microswitch Testing HELP - Now Fixed

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tags
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Roof Microswitch Testing HELP - Now Fixed

Post by tags » Fri 20 Jun, 2014 01:22

Hi All,

I have a small issue sometimes with my roof. Sometimes it works, sometimes it doesnt. Usually, when it does, it is likely to go up and down, up and down, no problem. And when it doesnt, it sort of does after you keep trying.

My break lights work, so I will rule out that for now. It seems it may be the microswitch in the roof. Does anybody know how to read and what i should see if i put a multimeter across the contacts on the switch? I am not an electrical engineer so would like some guidance. If it is the switch, i bought a maplin replacement that will need a little modding and soldering to get it installed. This I can do. I would like to test the current one though before I butcher it.

Thanks Guys.



Tags
Last edited by tags on Tue 01 Jul, 2014 22:39, edited 1 time in total.

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Brian H
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Re: Roof Microswitch Testing HELP

Post by Brian H » Fri 20 Jun, 2014 07:04

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HTH

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BladeRunner919
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Re: Roof Microswitch Testing HELP

Post by BladeRunner919 » Fri 20 Jun, 2014 08:01

You can also just test for continuity at the contacts to the switch, which is probably more accessible.

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lightning
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Re: Roof Microswitch Testing HELP

Post by lightning » Fri 20 Jun, 2014 08:35

The switch is available from BMW if needed, for about £60.
But an alternative can be purchased from Maplin for less than a fiver, although it needs a bit of work to get it to fit.

stevietgr
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Re: Roof Microswitch Testing HELP

Post by stevietgr » Fri 20 Jun, 2014 11:06

I had a similar problem when I first bought my Zed.

Turned out to be the switch in the centre console which I replaced with one from a 3 series convertible
from the local scrapyard. Cost = £10.

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Robert T
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Re: Roof Microswitch Testing HELP

Post by Robert T » Fri 20 Jun, 2014 11:13

It could also be the cable leading up to the microswitch. If you can bridge the pins in the connector you should be able to determine if it is the microswitch (or its wiring) or the console switch.

Cheers R.

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Re: Roof Microswitch Testing HELP

Post by sirius-c » Fri 20 Jun, 2014 11:40

stevietgr wrote:I had a similar problem when I first bought my Zed.

Turned out to be the switch in the centre console which I replaced with one from a 3 series convertible
from the local scrapyard. Cost = £10.

same here.
the part numbers differ but it works fine
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tags
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Re: Roof Microswitch Testing HELP

Post by tags » Sat 21 Jun, 2014 00:36

Thanks for the advise so far.

I am not sure that it is the Microswitch at fault. I managed to get the roof to go up and down tonight. I have left it this evening currently working.

What I have found tends to happen is that when the roof does not work on first attempt, I have to sit with my foot on the brake, finger on the roof down button and the roof opened and pushed up past the microswitch. I have to sit in this position for up to one or two minutes. And then, the roof works.

Tonight, I tried something different, whilst sat with foot on brake etc, after the usual minute or two, still no action. I lifted my foot off the brake and then back on again straight away and the roof started working. Does this mean that it could be the brake switch. I need to clarify by repeating the test next time the roof stops working, which happens to be every time I want it down.

Does anybody have experience of replacing the brake switch. My break lights work fine by the way. Is it possible for the brake switch to function correctly for the brakes but not the roof? And is it also possible for which ever switch is failing to fail and then suddenly work consistently?

Very odd...and I am confused.

Thanks.

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Southernboy
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Re: Roof Microswitch Testing HELP

Post by Southernboy » Sat 21 Jun, 2014 08:00

Brian H has probably identified the issue. If as you say you need to hold the roof up for a minute whilst depressing the brake and activating the console switch, it is likely that the connection of the micro-switch to the loom is faulty. The 2 connecting pins are prone to losing contact. Also as BH suggests, a break may have ocurred in the micro-switch section of the wiring. An erratic connection as you describe is most often in the wiring, but it can also suggest a micro-switch which is about to finally fail. The console switch is not as common a fault as the other areas, but equaly easy to test with a multimeter by removing it from the console, disconnecting it and checking the continuity for lowering and raising roof positions.
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Koolflyer
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Re: Roof Microswitch Testing HELP

Post by Koolflyer » Sat 21 Jun, 2014 09:32

Sounds like its probably not the pedal brake light/roof switch if you are sure that the brake lights come every time you press the pedal. However, if you find that this is the problem area, then replacing the switch is a cheap and easy job to do. Took me the same time to drink my mug of tea!
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Re: Roof Microswitch Testing HELP

Post by tags » Sat 21 Jun, 2014 16:58

I am not doubting you guys. However, i am struggling to understand the switch to be the issue if when it starts to work it works again and again. Also, it still confuses me that after a prolonged press of buttons, etc, it suddenly starts to work.

I have bought the maplin replacement switch and may give it a go. I may also just bridge at the connector to make the switch circuit completely closed and then I can see if I have more success before butchering the original switch. And I will end up making a botch up of it.

I will let you know how i get on.

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Robert T
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Re: Roof Microswitch Testing HELP

Post by Robert T » Sat 21 Jun, 2014 17:21

I would eliminate the microswitch first, as it is the easiest to get to. If you bridge the pins at the connector, then you will eliminate both the microswitch and the wiring leading up to it. If the roof still misbehaves, then you know that it has to be one of the other components.

I'd need to look very closely at the wiring diagram for the brake light switch - if it is a single pole switch, then the fact that your brake lights are working means that the switch is fine, if however it is a double-pole (or more) then it is possible for one set of contacts to fail whilst the others are still working.

There are other components that may fail - there are a pair of relays that control the direction of the pump motor and if one of these has sticky contacts, then this could cause the problem and re-energising the relay may clear it - you'd need to put an ear to them whilst someone else presses the buttons - you should hear them clicking.

It is a funny thing with the human mind how we can make associations between apparently unrelated things - unless you can categorically say that one thing is affecting another, you are more likely to be chasing a red herring, so you are better to just go through a process of elimination to get to the bottom of it.

Cheers R.
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Re: Roof Microswitch Testing HELP

Post by tags » Sat 21 Jun, 2014 21:45

I suspect the relays too. However, seeing as I can eventually get the roof to work, would that mean the relays have somehow re-energised.

Relays, is obviously the easiset fix. I have done the obvious, swapped them over, still the same. Are they expensive, I could look to replace if not.

Thanks,

Tags

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Re: Roof Microswitch Testing HELP

Post by g8jka » Sun 22 Jun, 2014 15:29

I had very similar problems, the roof would work fine for weeks and weeks and then would stop all of a sudden for a few days. Then it would work correctly for a while and then start to play up. It was very intermittent and there was no consistency of it working and not working. Because it didn't fail completely and would work as it should most of the time I thought it couldn't be the microswitch.

As the microswitch was the cheapest fix and was fairly easy to do with the maplins replacement I went ahead and gave it a go anyway not really expecting anything to change. I did a guide at the time and it is in the knowledgebase. Anyway ever since I changed the switch it has worked and has never let me down once. So after thinking it wouldn't be the switch, it turned out to be the problem. As its a cheap and pretty simple fix it is a great place to start eliminating the possible cause.
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tags
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Re: Roof Microswitch Testing HELP

Post by tags » Sun 22 Jun, 2014 20:26

i am going to go for it. Lets hope i don't botch it up.


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Re: Roof Microswitch Testing HELP - Now Fixed

Post by tags » Tue 01 Jul, 2014 22:49

I finally decided to cut the wires on the roof microswitch - what do I have to lose?

After cutting, I twisted the ends and the roof was working straight away. I proceeded to mod the Maplin switch. It is critical to try and make the modded switch as close to the original switch length as possible. I cut the U shaped switch end off the old one and superglued it over the new one. This was with limited success as the glue was not holding. My trick was to superglue as best as I could to get it in place and then slide some heat shrink tubing over and shrink it. That did the trick. However, the switch was slightly too long - meaning - when the roof was closing, the switch would activate and cut out the roof (as it should). Because I was slightly too long, when the roof was latched into position, the pressure on the slightly long switch meant that it forced it to make contact and the roof would still try to operate while closed. Fortunately, there is an extremely small amount of play in the switch housing and I managed to loosen the screws, push the housing taught away from the front and re-tighten (hope all that makes sense).

I soldered and heat shrunk the switch to the existing cut wires and now I have a fully working roof again. Thanks all for your input.

I get a new blue roof fitted on 19th July and I am looking forward to seeing my ///M back to its former glory.

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micahz3
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Re: Roof Microswitch Testing HELP - Now Fixed

Post by micahz3 » Thu 28 May, 2015 11:33

hi.

new poster, same issue.

why can't the roof microswitch be removed?

the ends of the wires would need to be twisted to make the roof operable when the dashboard switch is pressed.

why wouldn't this work?

i'm not lazy; i'm pragmatic.

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BladeRunner919
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Re: Roof Microswitch Testing HELP - Now Fixed

Post by BladeRunner919 » Thu 28 May, 2015 11:35

micahz3 wrote:hi.

new poster, same issue.

why can't the roof microswitch be removed?

the ends of the wires would need to be twisted to make the roof operable when the dashboard switch is pressed.

why wouldn't this work?

i'm not lazy; i'm pragmatic.
It can. It's there to stop you trying to operate the roof when the front hasn't been fully pushed up, which would cause frame damage.

micahz3
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Re: Roof Microswitch Testing HELP - Now Fixed

Post by micahz3 » Sat 30 May, 2015 01:03

ok, that makes sense, thanks.

at the other end of travel, when i retract my roof, the motor does not cut out when the the hood is fully retracted.

is this right? should the motor cut out when the roof is retracted?

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