Installation guide

4. Turn on the parking lights. If your meter shows (+)12V, turn off the parking lights and make sure it goes back

to zero.

5. If it does return to zero, turn the parking lights back on and, using the dash light dimmer control, turn the

brightness of the dash lights up and down. If the meter changes more than a volt when using the dimmer,

look for another wire. If it stays relatively close to (+)12V, you have found your parking light wire.

NOTE: Vehicles that use a (-) signal from the switch to the factory relay may be interfaced directly.

(See H1/5 WHITE wire of Primary Harness (H1) Wire Connection Guide section.)

An accessory wire will show +12V when the key is in the accessory and run positions. It will not show +12V during

the cranking cycle. There will often be more than one accessory wire in the ignition harness. The correct acces-

sory wire will power the vehicle's climate control system. Some vehicles may have separate wires for the blower

motor and the air conditioning compressor. In such cases, it will be necessary to add a relay to power the second

accessory wire.

To test for a tachometer wire, a multimeter capable of testing AC voltage must be used. The tachometer wire will

show between 1V and 6V AC. In multi-coil ignition systems, the system can learn individual coil wires. Individual

coil wires in a multi-coil ignition system will register lower amounts of AC voltage. Also, if necessary, the system

can use a fuel injector control wire for engine speed sensing. Common locations for a tachometer wire are the

ignition coil itself, the back of the gauges, engine computers, and automatic transmission computers.

IMPORTANT! Do not test tachometer wires with a test light or logic probe. The vehicle will be damaged.

How to find a tachometer wire with your multimeter:

1. Set to ACV or AC voltage (12V or 20V is fine).

2. Attach the (-) probe of the meter to chassis ground.

3. Start and run the vehicle.

finding the tachometer wire

finding the accessory wire