© 2004 directed electronics, inc.
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How to find (+)12V ignition with your multimeter:
1.
Set to DCV or DC voltage (12V or 20V is fine).
2.
Attach the (-) probe of the meter to chassis ground.
3.
Probe the wire you suspect of being the ignition wire. The steering column har-
ness or ignition switch harness is an excellent place to find this wire.
4.
Turn the ignition key switch to the run position. If your meter reads (+)12V, go to
the next step. If it doesn’t, probe another wire.
5.
Now turn the key to the start position. The meter display should stay steady, not
dropping by more than a few tenths of a volt. If it drops close to or all the way to
zero, go back to Step 3. If it stays steady at (+)12V, you have found an ignition wire.
finding the starter wire
The starter wire provides 12V directly to the starter or to a relay controlling starter. In
some vehicles, it is necessary to power a cold start circuit. A cold start circuit will test
exactly like a starter circuit, but it does not control the starter. Instead, the cold start
circuit is used to prime the fuel injection system for starting when the vehicle is cold.
How to find the starter wire with your multimeter:
1.
Set to DCV or DC voltage (12V or 20V is fine).
2.
Attach the (-) probe of the meter to chassis ground.
3.
Probe the wire you suspect of being the starter wire. The steering column is an
excellent place to find this wire. Remember you do not need to interrupt the
starter at the same point you test it. Hiding your optional starter kill relay and
connections is always recommended.
4.
Turn the ignition key switch to the start position. Make sure the car is not in gear!
If your meter reads (+)12V, go to the next step. If it doesn’t, probe another wire.
5.
Cut the wire you suspect of being the starter wire.
6.
Attempt to start the car. If the starter engages, reconnect it and go back to Step
3. If the starter does not turn over, you have the right wire.
