on my 94 integra its the white red whire that runs to the ECU, be careful there are two white red wires, one runs to the alternator the other to the O2 sensor. check the voltage of these two wires with the key in ACC, the onw with 5 volts goes to the alternator the one between 0.0 and 0.1 goes to the O2 sensor. if your car is different just look at wiring diagrams in a repair manual