i heard someone connected the vtec with just one wire i just want to know where does that wire go?

 

Two wires.

The one from the solenoid goes to ECU Pin A4

One from the oil pressure switch goes to ECU Pin D6, the other grounds on the motor.

 

The ghetto one wire vtec:

Hook up one wire on the solenoid to ground.
Then hook up the other wire to pass a push-activate (momentary) switch to a 12 volt source. It does not matter what wire goes to what, since its a solenoid, as long as the circuit completes.

there is a few of these 12 volt sources at the same location of your fuse box, plug number 3 activates when your key is in the ON position. This is assuming you have a OBD1 vehicle.

DO NOT HOOK IT UP DIRECTLY TO YOUR BATTERY, YOU WILL FRY YOUR SOLENOID.

You will get sick and tired of this extremely stupid way of using vtec very soon after; for it is annoying, inconsistant, and not realiable. But since you ask, there's an answer for you. Upgrade to a vtec ecu (preferable p28) as soon as you can.