2015 R172 Slk250 roof blowing a fuse

[lfckeeper]

Hello all

Wondering if anyone has any advice

The roof stopped working on my Mrs SLK, checking the fuses, fuse 75 (Vario roof control control unit) had blown, replaced it, it blew again.

Diagnostic comes up with 'right tumbler unit'.

Has anyone ever had this issue? Or any ideas on fixes before we get shafted by a repairer.

Cheers all

Graham

 

[st13phil]

Not experienced the issue myself, but it may be worth a search or post on the SLK World forum?

 

[lfckeeper]

Cheers I'll post on there too

 

[st13phil]

BTW, the "right tumbler unit" is the latch assembly at the front of the roof that secures it to the windscreen surround.

 

[lfckeeper]

I wondered if anyone could further help ....

The fuse that's blowing is circled in yellow

Following the lines it goes to 30_hut (red circle)

The next mention of 'hut' (30 being power ... Hut the abbreviation for what the wire does?) are circled green and leads to S69/4 and M28/18 .... These are the switches and motor for the shelf behind the headrest that flips.

Have I found the issue? Does that fuse lead to that shelf and it's either the motor or switches that are faulty.

Or have I gone blind looking at Mercedes wiring diagrams for no reason

 

[colinallcars]

I wondered if anyone could further help ....

The fuse that's blowing is circled in yellow

Following the lines it goes to 30_hut (red circle)

The next mention of 'hut' (30 being power ... Hut the abbreviation for what the wire does?) are circled green and leads to S69/4 and M28/18 .... These are the switches and motor for the shelf behind the headrest that flips.

Have I found the issue? Does that fuse lead to that shelf and it's either the motor or switches that are faulty.

Or have I gone blind looking at Mercedes wiring diagrams for no reason

What does the fuse allocation chart say the fuse controls and what is its rating? I don’t know if it’s the same on the 172 but on the 170 the fuse also protected the ecu cooling fan although this was undocumented. The fan would seize and blow the fuse. The way to test is to unplug the fan and see if the fuse still blows, if it does then it’s something else.

 

[lfckeeper]

What does the fuse allocation chart say the fuse controls and what is its rating? I don’t know if it’s the same on the 172 but on the 170 the fuse also protected the ecu cooling fan although this was undocumented. The fan would seize and blow the fuse. The way to test is to unplug the fan and see if the fuse still blows, if it does then it’s something else.

It's one of 4 fuses that just say 'Vario roof control' ...
The one that blows is a 20a fuse (fuse 75)

 

[Pontoneer]

I presume the SLK will have a procedure for manually raising or lowering the roof , same as the SL does ?

It could be worth manually unlatching the lock and greasing it . The latches on my SL were hydraulic , but perhaps on the SLK they are electric? If one is sticking , just needing lubrication , that might cause it to draw too much current and blow the fuse ?