Is Key Sense Wiring Necessary? 05 Ford Escape

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=100804
Printed Date: July 06, 2025 at 10:53 AM

Topic: Is Key Sense Wiring Necessary? 05 Ford Escape

Posted By: red85
Subject: Is Key Sense Wiring Necessary? 05 Ford Escape
Date Posted: January 05, 2008 at 7:56 PM

i am something of a newbie here, so bear with me. I have just gone through some training with ProStart (Auto Start) and I've been going over some wiring guides. Is it absolutely necessary to supply power to a keysense wire (+ polarity) if I am using a bypass module? If I have to supply power to this wire, where should I take it from? Ignition or accessory (1 or 2)? Thanks for your help in advance

Phil

Replies:

Posted By: chadwa2003
Date Posted: January 05, 2008 at 11:20 PM

What kind of vehicle and bypass module are you using?

Posted By: red85
Date Posted: January 06, 2008 at 5:47 AM

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?

Posted By: Chris Luongo
Date Posted: January 06, 2008 at 9:08 AM

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.

Posted By: red85
Date Posted: January 06, 2008 at 9:00 PM

Thanks for the reply!