Central Locking

[Dids]

My Central Locking on my Touring decided to give up this evening. Is there anything common that I can investigate or is it going to be a pig. Thanks.

[Brianmoooore]

Forum search for "red AND black AND wire"

[Dids]

Thanks. Will give it a go tomorrow.

[Dids]

Had a quick look this morning and it appears the Red/Black wire mod has already been done. Could it be the Control Unit at fault ?

[Brianmoooore]

Drag the locking ECU out of it's hiding place and check with a 12volt bulb that you have power across the black/red and brown wires at the locking ECU.
If there is, the usual problem is water into the ECU. Open it up and see if there's corrosion inside.

[Dids]

I've got live at the black/red and the ecu is bone dry, although it looks as if it has been played with before.

[Brianmoooore]

I've got live at the black/red and the ecu is bone dry, although it looks as if it has been played with before.

Checked with a 12V bulb? Meter is useless for these sort of tests.
Bottom left hand corner of the locking ECU PCB there is a thermal fuse, which consists of a soldered spring next to a resistor. If the resistor gets hot enough, then the solder melts, the spring flips back and power to the unit is cut off.
Check this fuse out, and if it's tripped, solder it back, BUT don't use any extra normal solder. The original is special low melting point stuff and fires have been caused by using normal stuff!

[Dids]

I used a proper test light, and I'll check that out.

[Dids]

I've just noticed if when I lock and unlock the car I can hear a relay switching. Does this mean the ecu is working but there is another problem ?

[Brianmoooore]

I used a proper test light, and I'll check that out.

If you mean one of those little screw driver type things, I'm not really sure how much power they draw. Certainly a lot more than a meter, but not really enough to test properly. Borrow a 21W indicator bulb and check that it lights at full brightness.
Once I'm convinced that you have power at the ECU, I will give you some tests to do at the ECU socket to check out some more of the system.

[Brianmoooore]

Going out for a few hours now, so here it is anyway.
Remove the ECU and link pin 2 (white) to pin 4 (brown).
Connect pin 3 (red/black) MOMENTARILY to pin 1 (blue). This should lock the doors.
Now connect pin 4 to pin 1, and pin 3 momentarily to pin 2. This should unlock them.
Lock them again and c0nnect pin 11 (black) to pin 4 (brown) and pin 1 (blue) momentarily to pin 3 (red/black).
This should engage the deadlocks.
1 to 4 and 11 momentarily to 3 should unlock them.