Anyone familiar with mercedes vacuum central locking? Keyless install problem.

[owas]

This is on my w124 250d

The central locking works off the key, I see people install these cheap keyless fobs to the central locking pump wiring.

Wired it all up correctly to the main pump green wire and positive/negative.

When I click the unlock/lock button it works correctly but reverses locking/unlocking straight away.

So if I lock it while it's unlocked, door pins will go down but then instantly back up again.
Do it on the key and it stays down.



It's not essential,just thought it would be nice to have,will pull it out if I can't get it to work.

https://www.amazon.co.uk/AUTOUTLET-Universal-Keyless-Vehicle-Controllers/dp/B07RGTG7GD/ref=mp_s_a_1_3?crid=2ROYPBJ6ISYTE&keywords=keyless+entry+door+lock+car&qid=1656711156&sprefix=keyless+entry+door+lock+car%2Caps%2C70&sr=8-3

 

[CompoSimmonite]

You get the same happening with any central locking if one door / boot isn't fully closed. Could it be there is a leak in the system and the signal from the fob isn't long enough for the pump to counteract the leakage ?

 

[owas]

I worked it out,
This little black plug just needed moving over to the other two prongs.
Works really well now.

 

[pedrobedro]

I worked it out,
This little black plug just needed moving over to the other two prongs.
Works really well now.

View attachment 353771

That's called a jumper