Trouble Shooting Guide – AMP Research Power Step
The wire colors on my vehicle do not match the colors in your diagram. What do I do?
Unfortunately vehicle manufactures frequently change the color of the wires in their wiring harnesses. The wire that we need locate is the factory door-ajar signal located inside each door. You can find this circuit by removing the door panel and physically tracing the wires leading to the door latch / switch. Once you have located the bundle of wires that go to the switch you will need to isolate the door-ajar circuit. This circuit will be a “negative switching” circuit. Negative switching indicates that the circuit will be in a “ ground “ state where the circuit is connected to the minus or negative side of the battery with the door open (Except 02 – 03 Ford Super Duty and 08 Ford Super Duty where the circuit is closed to ground with the door shut). With the door closed the circuit will sometimes show a very small amount of current or nothing at all.
The best and safest way to isolate this wire is to use a computer safe circuit tester like the CTS24 Circuit Tester by Blue Point available from Snap On Tools. There are other manufacturers of similar testers. The important thing about this kind of tester is that it is specifically designed to be “computer and air bag safe”. This means the tester will not damage sensitive electrical systems.
A multimeter or continuity tester can also be used by setting the tester to the Ohms setting and connecting one probe to the negative battery terminal and probing the previously located wires. With the door open, operate the door latch with the door handle to open the latch. Manually close the latch with a screwdriver or other tool by actuating the latch and simulating the strike pin located on the doorjamb. The correct wire will change readings on the tester from no continuity to 100% continuity when opening and closing the latch (Except 02 – 03 Ford Super Duty and 08 Ford Super Duty where the circuit is closed to ground with the door shut). Or when using a tester like the CTS24 the reading will change from green (indicating ground or minus) to nothing (in some cases red). Complete the balance of the wiring per our wiring diagram.
Get pdf Trouble Shooting Guide – AMP Research Power Step
