93 240sx power lock problems

Hi everybody. I have just finished installing an alarm I bought, and I am having a problem. The doors will unlock and lock, but they won't STAY unlocked. the alarm I have has a -ve output for lock and unlock, and the car uses a single wire setup. So I set it up according to the diagram I found: I guess the problem is that when the alarm pulses the signal to unlock the doors (IE ground the wire), the doors will unlock, but then lock again as soon as the pulse is stopped. I'm not bad with electrical stuff, but not great either. I can't figure this out, despite several hours of searching and reading. Is it a bad diode, perhaps? I tested it with my multimeter and it seems fine.. Any other ideas? TIA.

Oh, by the way, this is a Canadian model, if it makes a difference. It does have stock actuators in both doors.

do you have your unlock output on the correct side of the CUT wire? Remeber it goes on the module side NOT the swotch side. Also...the diode placed in the correct posistion  (cathode end facing the rite direction)???

Yeah, the diode goes the right way and the relay is set up exactly as in the pic. But the alarm doesn't ground that unlock output forever, it just grounds it for a second, then it stops grounding it, which opens the circuit again. :(

Hold on a second. I think I found it. Should the switch be connected to 87 and not 87a? Then the switch would still work (right now it doesnt) and then when the lock lead is grounded, it will disconnect the connection, opening the circuit, locking the doors! Hah. I'll go try that.

You sure you have the switch side on 87A, and make sure your relay has an 87A...I have come across some that have 2 87's.

I did make sure it was on 87a, but after looking at it, if 87 is NC, wouldn't it make sense to use that one insead? I think I'll try..

So I just pulled the diode out and tested it.. I got zero current through it backwards, but when testing it forwards, instead of reading 0 resistance, I got like 200 ohms.. Is that normal?