Can I install a Pioneer Avic Z1 into a 2002 gmc jimmy?if so is there a dash kit and wiring harness available?

Could be a ground problem. You take the ground out of the harness and run it to the body or run a ground from the radio back to the body or both.

Click on this link and scroll down slightly and click on GMC, and scroll for proper year and model.

http://www.the12volt.com/

AD-GA10: Offset installation kit that allows your unit to be installed a further 10mm recessed into the dash. Check to ensure proper rear clearance (depth) behind the unit before installing this kit.
Hope that helps.
Good luck with it

http://www.modifiedlife.com/2003-gmc-sierra-c1500-car-radio-wiring-guide/

Here is a written diagram. This site, along with many others, offer a pre-wired harness for easy plug and play installation

go to local parts house an get the rite harness for your truck look under back of truck unplug harnes an plug your kit in between factory harness

Your going to have to remove the tail light assembly to get to the running and brake lights wire harness and just tap in to the wires for the trailer light kit. Good luck and hope this helps. 

well to start you will nee an install mounting kit metra number 99-7423,
a wire harness 70-7552
and an antenna adaptor number 40-NI12

Now to remove the stereo you will need to pop off the trim ***. just below the heater control switches. the the vents above the radio. remove four phillips screws and then pull stereo/ heater assembly from dash.

you can probably purchase a harness from clarion to fit strait into the gmc harness, if not the only place you will get the wiring schmatics is from a workshop manual for the jimmy which will probably cost you more than the harness

You have to unplug the old radio. The radio isn't the part in the dash. That is just the control to the radio. The radio is actually under the dash above the accelerator pedal. It should have the power wires, speaker wires and antenna wire going to it.

You should have a wiring harness already there. There will be a plug with 3 female and one male connection. White is ground, Green is right turn, Yellow is left turn and Brown is tail lights. If you are installing a brake controller. You will have to run a 10 or 12 gauge blue color wire.