Need wiring diagrams for 1999 GTP.

im afraid that unless you luck out and find them online somewhere, youll have to get a service manual

Dude, you lucked out...lol.

I have this posted on my site somewhere.

www.pontiacunlimited.com (http://www.pontiacunlimited.com) (We have nearly Unlimited resources in the Pontiac world.)

I'll find it and post a link for you.

Found it. Here's the link to the page with it on it.

97-03 Grand Prix Wiring Diagram (http://www.pontiacunlimited.com/__Uploads/images/Wiring%20Diagram.JPG)

If you need anything else, just PM me on here, or feel free to check out all the info we have up on our site. There are plenty of mechanics and guys to get the answers you need.