OK. 2 amps or so shouldn't be enough to cause too much trouble.
On that basis, I am just going to guess that you have dislodged something while futzing about under the dash. You should get the wiring diagram for your car, or a similar car (hint, later R34 or V35 types might be close enough to show you how Nissan were doing things) to see where there should be power, where there should be earth and what sort of plugs might be involved under the dash. Then go probing with a multimeter to find out where the pixies are and where they aren't.