ignition 2 wire

I have 2005 Mercury Sable. I want to install a Design Tech Remote Starter. Model # 20092. I have a question about the Ignition 2 wire on this model of remote starter. This wire shows a negative so I will have to add a relay, but my question is cant you just run another wire off of the ignition 1 wire on the remote starter to the second ignition wire on the vehicle. Also this is an older model starter does it need to be initialized before the first use. Thanks for your help.

No you cannot! all wires, once from oem specs are part of a seperate circuit, they must remain that way!

Ok I will hook up a relay to the second ignition wire negative.  I need to hook up a relay to make this wire positive right? Do you know if this unit needs to be initialized. Thanks for the quick response.

Convert a Negative Output to a Positive Output

If you have a switch or an alarm or keyless entry that has a negative output that you wish to use to switch a device that requires 12V+ such as a horn, dome light, parking lights, head lights, hatch release, etc., wire a relay as shown below to convert the negative output (trigger) to a positive output. Here's the same configuration showing a negative output from an alarm or remote keyless entry used to activate a trunk release solenoid that requires 12V+ to release the trunk.

Most units require some sort of "initializing"... Is that the candy-bar , rectangle looking unit...Or more square...?

The unit is more square. I was reading up on some of the newer ones and it says they need to be initialized. It does not have valet switch, and is starter and alarm combo.