Aftermarket remote unlocking problems.

[ss2115]

Hi.
I've fitted an aftermarket remote to my late 92 525i Touring - RHD (Australia).
Instructions said to fit behind the drivers kickpanel and not under the back seat.
Found the lock and unlock cables - White/green/yellow and White/green according to the wiring diagrams for "later production vehicles".
[the White/red/yellow does not exist]
There is a Blue/brown/yellow which does double lock if the remote lock output is put directly to it, but wont allow the unlock to work.

The problems -
The system will lock and unlock okay. But I cannot get the double lock to work using the diodes as described. It will lock, but not unlock, and it will still only lock normally and still not double lock.
Yes - the diodes are the correct way around and yes they are working - tested to flow in one direction and not the reverse.
If I use the extra wire provided for the comfort windows through a diode as shown, it will double lock and put up the windows, but I cannot unlock the car by the remote and have to use the key.
Also, if I just put up with normal locking and unlocking and forget about the double lock and the windows, it works reliably while being tested but if the car is left overnight, it won't unlock in the morning and I have to use the key. Then if tested it works perfectly again. Its as if after a set time the power turns off.

This is supposed to be a system for the E34 including the comfort windows, but its been a curse. When installed out of the box as described, it would double lock and raise the windows, but wouldn't unlock. The diodes were all installed in the loom and shrink wrapped, so I ended up taking them all out and starting from scratch which has gotten me to the point described as above.

At this point of time I'm wondering if the GM or wiring is that much different for a RHD, although I've taken off the passenger side kick panel and the wiring is all the same colours.
I've looked at the plug under the back seat and the colours are nothing familiar and there's only half of the 12 pins in there anyway.

I deally I would like to replicate the door key action - ie: lock normally, double lock without raising windows, and raise the windows. Here in hot Sydney, we often like to leave the windows open a crack to let out the heat and this is where the double lock is handy because anyone with a coat hanger or strap cannot use the cracked open window to raise the locking button or try the inner handle.

I'd love to hear from anyone who has had similar problems and solved them.
I don't think its entirely the remote unit to blame - I think it may be something different with my car that the remote isn't coping with or is incompatable despite it being supposedly for an E34 5 series BMW.

As an afterthought, most of the descriptions of the wiring that I've searched for in this forum and in the remote desriptions themselves always mention yellow dots on the wires when there is a third identifier. My car has no yellow dots - they are a solid colour, with the second colour as a solid stripe, and then the yellow is a fuzzy stripe circulating around the wire - no dots.