adding defrost to RS for sunfire

Hi Everyone,

This is a great site, and thanks to many people on this forum, i was able to install a prostart starter on my 2000 sunfire this past weekend.

i do require some more help, i have a third channel trunk output that i am not using and would like to dedicate it to the rear defrost if possible.

the RS wire is a 500mA negative output (1 sec pulse), operates only when ignition is OFF or when the vehicle is running under remote control.

anybody know what wire at the switch should i tap into? will i need to add relay circuit?

thank you.

If you are able to access boths sides of the Defroster switch and make connections to the terminals in parallel, you can try something like this, using a relay:

Pin 85 - Constant +12V

Pin 86 - Negative pulse from trunk output

Pin 87 - One side of Defroster switch

Pin 30 - Other side of Defroster switch

Here is some information regarding relays:  https://www.the12volt.com/relays/relays.asp

-Michael

http://www.velocitymotorsport.com/images/install_notes/106.jpg Check that out.  Good luck!

tim