Do I need to buy an additional harness for my Chevy Tahoe, or does every thing I need to install in in my car come in the P3 package?
If your Tahoe has factory installed Tow Package, a 7-pin Bargman box with wiring should already be ready for towing. To use the Tekonsha brake controller, this $15 cable harness
(for 2003-2006 or this one
for 1999-2002) makes completing the installation quick and painless. In anticipation of getting my new Casita
17, today I installed a similar Tekonsha cable in my Nissan truck (Prodigy controller from Casita
13' ownership 7 years ago). It was "plug and play" at its best!