R107 Wiper & Central Locking Problems

[Davidt]

Hi,

I'm new to this forum and so I hope I have posted in the correct area - forgiev if this is wrong.

I have a 1979/80 450 SLC which has two problems that I hope someone can help me with.

1. The delay wipe/intermittent position has stoped working, it occasionally failed to wipe on intermittemt but now really has failed altogether. Also at the same time, the 'self park' no longer works. I assume that the delay wipe simply uses some relay to 'trigger' the wipers and the self park then 'parks' them until they are triggered again.
So my guess is that perhaps it may be the self park that is the primary issue and this is causing the delay wipe from operating?



2. I am having a locking - or rather an unlocking problem - the central locking works fine on doors, boot and petrol flap. Unlock it shortly after locking and all unlock. Leave it a while, and attempt to unlock it and although the doors unlcok, the boot remains locked. On starting the engine, then 'unlocking' using the fob and the boot unlocks.
I appreciate I have a leak somewhere in the system, but anyone any idea where I start to look for it?

Any help, very much appreciated.

Regards
David

 

[Dec]

Hi David, with the wipers turned on to the intermittent setting it should be possible to hear, from under the open bonnet, the relay click every 5 seconds. Do the other speed settings work ok?

Your wiper motor will work in a similar way to a W202 wiper motor below, it would worth checking it out to see if any of the switches or rails that the switches contact are in any way damaged, I wouldn’t know how you would access the motor in your car.

1. Is always live when the ignition is on, this keeps the motor running to allow the blade to get back to park, regardless if you switch off the wipers at the stalk switch in mid sweep, when switch 1 meets the gap in the inner rail, the motor stops and the blades park.

2. Continuous power.

3. Is intermittent, this kick off the motor and is connected to the outer rail, Note the photo gives the impression that there are 3 rails, there are only 2.

The only thing I know about the lock problem is that some locks have 2 key locking positions, 10 o’clock and 2 o’clock however on some Mercs there is also a 3 o’clock position and if the key is withdrawn in the 3 o’clock position the boot remains locked even if the doors are opened, any chance that this could be the cause of the problem.

Dec