Door trigger question?

Hi, I was wondering if anyone could tell me how to check to see if my door triggers are -output or +output. I have a 97 Blazer and i'm installing an alarm keyless entry system. I have a DMM but not exactly sure how to check this. My alarm has these inputs:
Violet: (+)Door Trigger Input
Green: (-)Door Trigger Input

According to the diagram I have for my Blazer it's:
Lock: Lt.Blue
Unlock: White
So how do I check this with my DMM to find this out?

Any idea on how to hook these up? I don't mean to sound so stupid but the weather is finally starting to get nice here and I want to have as much knowledge about this as possible before I go diving into it. Thanks for any help.

If you have keyless entry from the factory then they are positive and you have to DO THIS. Probe the wire (pierce the insulation) and your DMM should go +12v when you push on the matching button. Tap into these wires

If you don't then you DO THIS. Same thing applies with the DMM as above. The wire should only go + when the correct button is pushed. In the 5-wire you have to cut these wires in half, ALWAYS test the wires again. The wires going to the motor will not change with either button (they are cut) the switch side will still go + when the correct button is hit. Wire backwards and pop goes your fuse.

FUSE the door relays (either case).

Good Luck.

|       ITEM      |     WIRE COLOR     |POL|       WIRE LOCATION        |
|              12V|red                 |+ |ignition harness            |
|          STARTER|purple or yellow    |+ |ignition harness            |
|        IGNITION|pink               |+ |ignition harness            |
| SECOND IGNITION|white or pink/white |+ |ignition harness            |
|        ACCESSORY|orange              |+ |ignition harness            |
|       POWER LOCK|lt. blue            |+ |either kick panel *2        |
|     POWER UNLOCK|white               |+ |either kick panel *2        |
|       LOCK MOTOR|gray               |   |drivers kick panel          |
|     UNLOCK MOTOR|tan                 |   |drivers kick panel          |
|    DISARM DEFEAT|tan                 |   |passengers kick panel       |
| PARKING LIGHTS +|brown               |   |switch or rear harness      |
|       HEADLIGHTS|yellow              |+ |at switch                   |
|     DOOR TRIGGER|white *3            |- |keyless module *2           |
| DOME SUPERVISION|use door trigger    |   |                            |
| TRUNK/HATCH PIN|tied in with doors |   |                            |
|TRNK/HTCH RELEASE|BLACK/ white        |+ |switch or keyless *2        |
|       TACHOMETER|white               |   |ECM *1                      |
|       BRAKE WIRE|white               |+ |at brake pedal switch       |
|     HORN TRIGGER|black               |- |steering column             |
|           WIPERS|purple              |+ |left of column              |
| LF WINDOW UP/DN|dk. blue - brown    |A |in drivers door             |
| RF WINDOW UP/DN|dk. blu/wht - tan   |A |in drivers door             |
| LR WINDOW UP/DN|green - purple      |A |in drivers door             |
| RR WINDOW UP/DN|lt. green - pur/wht |A |in drivers door             |


Notes:
*1 The ECM is located on the passenger inner fender well. Located the white
wire in a black plug labeled 'white'. *2 Also found at the TRW keyless entry
module mounted to the under dash panel on drivers side. With the module
unplugged, the drivers door lock will no longer function. *3 This wire
catches all doors, but reads the delay. To keep the alarm from reading the
delay, place a diode in-line on the white door trigger wire with the anode
towards the keyless module. Attach your door trigger wire to the cathode side
of the diode. On non-keyless models there is a module with 5 wires located
where the keyless normally resides. The white wire there catches only the
front two doors. To catch the rear doors use the white wire at the drivers
side rear pin switch.