What do these wires do? Chinese Alarm System

Here is a pic of the chinese alarm i bought off ebay It comes with a SPST(i think) relay for the starter interrupt and also a pre wired socket, would I need the diode? For the domelight illumination, given that the alarm has both positive and negative wires coming out of it, means it has an onboard relay? So I connect one end to negative door trigger and one end to +12 volts DC? Or I use a SPDT Relay?

Buy a diode, 1N4004 and USE it. Any decent make would already have the diode built into the relay plug. As for domelight supervision those two wires are simply alarm triggers from either a POS or NEG going switch. When you shut the door does the dome light stay on, dims after a few seconds? But when you lock all doors does it go out immediately? If so like most Hondas and Toyotas you already have dome light supervision in the vehicle.

4 wire 4 pin is SPST relay. Still use a diode as it is recommended. No the +12 doesn't get hooked up if you have a negative trigger. Only one wire is used depending on you trigger type. No relay should be needed as the unit should be capable of driving the dome internally.

Lurch means use the green wire not the violet and ignore the blue/white below.

As this is a Chinese alarm Connect the Green wire to the door trigger and verify that it works to turn on the domelight supervision with unlock and that alarm triggers when individual doors are opened.

Flushing out how it works and what each wire is, is a must with Chinese alarms and there poorly written and translated manuals. As they don't always follow any one standard for the functions and how they are applied or use diodes for starter relays.

Ok given that the relay that comes with the alarm has the pre-wired socket, how do I install the diode? Should I solder? Also let's say the relay already has a built in diode and I add one externally, does this cause a problem?

Solder with band to ignition input. If there's already a diode you won't need another.

I bought this diode, I hope it will get the jobe done. Diode

@howie, so how would I know if it already has a diode in or not? In case I install it and there is one already internally, what happens? Could you please also elaborate more on installing it?