Reported Problem: Aftermarket Kill-Switch. No Power Reaches Starter Motor when trying to Crank/Start (all other functions on the vehicle work fine):
We get this call periodically, especially when after someone has purchased a used vehicle with no knowledge of an alarm system even being on it and no remotes came with the vehicle:
Commonly known to happen on aftermarket alarm systems when a remote transmitter (a.k.a. FOB) is lost or broken. Normally before the vehicle is entered the unlock or disarm button on the remote is pressed which unlocks the vehicle's doors while at the same time disengages the system's internal or external anti-theft starter-kill circuit (a.k.a. kill-switch).
This can cause a problem after the remotes are lost or broken if the system was last locked/armed with the remote before the remote was lost or broken and you are now entering the vehicle using a key. Or the vehicle was serviced and the service required disconnecting the vehicle's battery and upon reconnecting the vehicle's battery, the alarm triggered (main reason why to always have a spare remote).
Without a working remote the only way to fix the problem will be to get to the wiring from the system that's stopping power from reaching the vehicle's starter motor. This almost always requires dropping down the vehicle's knee-bolster panel (the panel that's directly across from your knees when your sitting in the driver's seat) and locating the aftermarket system's main control module.
After the system's main control module is found you will want to look on the module for the brand and model numbers on it. Most system module's will have this information on it, but not all. Knowing the brand and model of system will make it easier to find out what type of anti-theft circuit the system has. If your module doesn't't have any descriptions as to what the brand and/or model it is, not all is lost. There's commonly only 2 types of aftermarket anti-theft circuit designs, internal and external.
If you have a system with an internal (or built-in) starter-defeat circuit (usually found on older systems) you will find 2 wires of the same gauge (size or thickness) and color (one of the two wires may have a color trace or stripe on it). Commonly these wires will be found running into a separate plug on the module or at least side-by-side when found mixed in with other wiring running into the module. But again, they are going to be the same color and gauge no matter how they are found. When you think you found these wires, one way to test to see if you found the correct wires is using an appropriate 12V test probe connected to chassis ground, only one of the two wires will show momentary +12V power only when you try to start the vehicle, the other will show no changes.
After confirmation simple apply a jumper across these two wires so the power from the one wire will reach the other wire during starting of the vehicle. Finally, if the alarm also keeps sounding, just look for some inline fuses on some of the system's wiring and pull them out. Now you can leave the system like this until you get a new remote without having any further starting problems or the alarm triggering.
Now on system's with external starter defeat circuits you will commonly find an external automotive relay with just one wire running from the system to the relay harness. This one wire from the system is the output that is triggering the starter-defeat relay when the alarm is triggered and preventing the vehicle from starting. Commonly found on most systems as a thin gauge Solid ORANGE wire, all that is required is to cut this wire in half then, as with the internal relay types, locate any fuses to the system and pull them out to prevent the system from sounding/triggering.
