Is Key Sense Wiring Necessary? 05 Ford Escape

What kind of vehicle and bypass module are you using?

05 Ford Escape and a TB-350 (AutoStart) bypass module.  I can't remember if that keysense wire is + or - polarity.  At any rate, what is the rule of thumb here?  If it's a - do I use the ground out while running connection on the r/s module?  If it's + where should I supply the power from?

It seems that all the tech sheets these days list the car's keysense wire, whether it's needed or not. Most of the time, it isn't necessary. And you asked about rule of thumb? You'll get a lot of different opinions. My rule of thumb: Older Saturns need keysense, or the check engine light comes on. Toyotas that have factory alarms need keysense, or the alarm will go off. On European cars, it's wise to power up ALL accessories, including keysense, because those cars can be so finicky. Other installers' rule of thumb: Power up as many circuits on the car as you can, to duplicate factory operation as best you can. Ford Escape: I only connect three wires at the ignition switch: Constnat, Ignition, and Starter. This way, not only is the job easier, but the radio remains off during remote start. Other installers not only power up the radio, but they use the remote starter's Ignition 2 output to the car's keysense wire. In this way, it's 100% like factory, and guaranteed to work right the first time.

Thanks for the reply!