e30 cabriolet central locking red/black mod

[viz007]

Hi All
I know this topic has been covered extensively but I wanted to clarify something before carrying out the modification and do it wrong!

The wiki says that there are 3 wires to join in the cabriolet models. From what I can see:
1 wire leads straight to door plug
2nd wire leads to CLU
I undertand these are the 2 that would be normally joined as described.

The 3rd wire appears to go from the CLU into the door plug.

So do I join wire 1 and 2 as normal and the 3rd joins from the CLU to the join made above? IE neither red/black connections remain from the door plug.

[daimlerman]

Hi All


So do I join wire 1 and 2 as normal and the 3rd joins from the CLU to the join made above? IE neither red/black connections remain from the door plug.

Correct.

My original wiki article made it clear that the aim was to eliminate the red/black looping through the door/A pillar plug/socket,unfortunately this part was 'edited' out!

This connector is known to corrode,a proccess encouraged by a permenant live feed passing through it.The red/black wire only enters the driver's door to feed the (optional) heated door lock,a feature that is very rare on UK spec E30's,so can be removed without any other issues.

[viz007]

Thank you for your fast response. I'll give it a go this weekend!

[Brianmoooore]

One red/black comes out of a small loom that runs along the sill from the back of the car, another goes to the locking ECU socket, and the third goes to the smaller socket for an interior light delay relay (which probably isn't fitted on your car).
Cut all three of these wires away from the socket in the A pillar by reaching through the hole for the loudspeaker, solder them together, and insulate. None of them should be left connected to the A pillar socket.
There is also a red/brown wire that goes to the socket - don't mistake this for red/black.

[viz007]

I haven't done the mod yet but managed to fix the central locking by resoldering a component on the circuit board of the CLCU. I will still be doing the mod another day.

[Brianmoooore]

I hope that this resoldering didn't involve the addition of any fresh solder (assuming you're talking about the thermal cut out spring.) This was originally soldered with a special very low melting point solder, to form an important safety device.
If you've added conventional solder, especially that useless modern lead free stuff, then the ECU needs to be replaced. The fuse for the central locking provides short circuit protection only, not the more important overload protection.

[viz007]

Thanks for this. I have seen various low melting point solder available to buy. Do you know whether it is ok to use something like this or am I just better off replacing the central locking unit.

[Brianmoooore]

The problem is that we don't know what particular solder was used to be able to repair the spring and retain its effectiveness.
The heat generated by the resistor should be minimal in normal use, so I'd go for about the lowest melting point stuff you can find. 130 degree at the absolute highest, and preferably lower.

[viz007]

The low temp solder is quite expensive so I managed to find a replacement unit online for less. Thanks for your help