2000 xterra ac issue

did you power all ignition and acessory wires? one thing ive read and learned a lot from here is if youre vehicle has xx amount of ignition acessory or starter wires you should simulate what using the key does and power all the wires. how many do you have, vehicle wiring on here shows 1 starter, 2 ignition and 1 acessory, how many did you find with the dmm

There seems to be some conflicting info on the ignition wires for this vehicle.

Here is info from Audiovox:

 Battery        WHITE/ BLACK  (+)     IGNITION SWITCH HARNESS  

Here is info from Bulldog Security:

 12 VOLT CONSTANT            GREEN (+)           IGNITION SWITCH HARNESS 

Here is info from this site:

Constant 12V+    Green           Ignition Switch Harness 

Looks like you will need to use your Digital Multi Meter to locate and verify the correct wires. 

Nissan's Field Service Manual data shows that the RED / Yellow Ignition 2 wire runs the blower motors, Heat & A/C.  This signal is active in the "ON" position, and drops during start--functionally it is an accessory wire.   Nissan also shows a GREEN/ YELLOW Starter 2. 

This information is consistant with DEI/DirectWire info below:

12volts	green	+	ignition harness
Starter	BLACK / YELLOW	+	ignition harness
Second Starter	GREEN/ YELLOW	+	ignition harness
Ignition	BLACK/ white	+	ignition harness
Second Ignition
Third Ignition
Accessory	RED / yellow	+	ignition harness
Second Accessory	WHITE/ blue	+	ignition harness

Note: When doing remote start, this wire must be isolated from the key switch with the accessory relay. See Tech Doc 1077 for wiring information.

 I agree with Kreg--use a multi meter to identify the correct wires. This should be standard practice for all wires during an install.  The info here may help narrow your search.