R230 - Boot separator latch switch repair

Conor

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Hi all,

I recently encountered a well known issue with my R230 SL, where when you try to lower the roof and the boot separator is already closed, the car tells you to close the boot separator... the most common reason for this is an inoperative microswitch in the boot separator latch.

Here is how I troubleshooted and resolved the issue.

TLDR: I took dismantled the latch, and swished it around in some contact cleaner .. the switch was back working a few hours after cleaning it.

First off, once I discovered the problem, I was 90% sure that it was the microswitch .. so with this in mind, I removed the latch housing as shown below.

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With the latch removed, I cut the wires coming from the latch/switch housing and joined them together. With this completed, the roof worked as expected. This was a good temporary fix and also confirmed the root cause of problem.


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Once back at my workshop, I dismantled the latch mechanism.

Remove the two screws shown below, along with the connector, to reveal microswitch mechanism on PCB.

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In order to clean the conacts, PCB and microswitch, I sprayed some electrical contact cleaner into the lid of the spray bottle. I then submerged the PCB and switch in the cleaner and swished it around a bit..
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I also de pinned the connector and cleaned those pins too.

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I then waited a while for the contact cleaner to evaporate off and tested the mechanism.

Please note: The switch operates contrary to what people might think. Microswitches come in various guises, and this one is a "normally closed", meaning when the switch is not pressed, the circuit is closed (wires connected).. when it is pressed the circuit is open, and current cannot flow. Also, when the boot separator is open, the switch is pressed, meaning there is an open circuit. It is only when the boot separator is closed and the microswitch is not pressed that the circuit is closed and current flows. This is why cutting the wires and joining them by hand works.

 
OP
Conor

Conor

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It is worth nothing that if you have a piece of wire to hand (Or a paperclip) you can just remove the connector from the latch housing and short the two pins of the connector.. this means you don't have to repair the chopped wires later (like I had to....)

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Blobcat

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Copied to DIY Here
 

mioba

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Good info and diagnosis. job well done!
Not a fan of spade connectors myself. Could have been neater by removing wires from connector.
 

D Bee

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Is it true that the 'boot separator' dashboard warning comes on if the PSE pump fails? I need to know before buying a new separator switch or sending the the PSE pump off for repair.
 

alexanderfoti

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Is it true that the 'boot separator' dashboard warning comes on if the PSE pump fails? I need to know before buying a new separator switch or sending the the PSE pump off for repair.
This is a failure mode of the PSE pump, as the switch is wired into the pump. However there are lots of other ways that the PSE pump can fail that doesn't cause the issue.

Simple enough to test the switch and rule it out.
 

D Bee

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Many thanks for your answer. I often feel that these cars are too sophisticated and complicated for their time - great to drive but one problem after another and often difficult to diagnose faults.
 
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Conor

Conor

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Dodgy cutting the cables rather than disconnecting the connector though…;):rolleyes:

Yeap.. I was just out at a friends house (car enthusiast) and we were just about to set off on a longish drive.. we really wanted the roof down.. so I just snipped the wires and connected as a quick fix.

In that moment, I didn't think of de-pinning to connector, if I am honest. Hindsight eh..
 

Danny_Labrador

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That's great post - certainly given me confidence to have a go at the job.

I found today that it was the plug and socket that were the issue. Switch cleaner seemed to sort it out but does anyone know if the plug and socket can be bought ??

Thanks
 
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Conor

Conor

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That's great post - certainly given me confidence to have a go at the job.

I found today that it was the plug and socket that were the issue. Switch cleaner seemed to sort it out but does anyone know if the plug and socket can be bought ??

Thanks

No problem, glad to help..

You can buy the whole assembly that contains the switch (inc. socket) .. but it was kinda expensive for what it was.. I think between 50-100 euro... I was absolutely loathe to pay it.

I don't have the part number I am afraid, but I am sure somebody could get it for you if needed.
 

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