02 trailblazer, new head unit

I would reccomend using a OEM-1 bypass moduel instead of the relocating harnes. you will get much better results. Drawback is there kind of expensive.

PS. The OEM-1 is made by PAC

...one thing to keep in mind is that with the relocation ahrness you dont ACTUALLY ave to relocate the factory radio (you can just hide the plug under the dash somewhere, the only down side is you loose your chime system....(for me personally that was a Upside to the install......nothing i hate more than hearing a stupid chime when im ripping my e-brake through dirt parking lots!

http://www.cardomain.com/ride/2084619/6

With the RDS radios, if you use the bypass modules can you still program your settings that use the factory radio? Keyless Entry, Tire Pressure Light, Low Oil Light, Oil Change Light, etc.? I am getting ready to change the one in my 2000 Impala.

customcutlass92, when u swap out youre rds radio, the only way to reset all the lights (with the exception of youre tire pressure light) is to purchase the relocation harness. As mentioned before, it does not actually require you to move you're factory radio somewhere else, but assuming you dont, you will loose your chime system. If you do relocate the factory radio (i.e. the trunk) you will be able to still reset all of the lights and program you're keyless entry. What i did was use the relocation harness (mainly due due its price vs. metras gm-rc01 which eliminates the need to keep the radio in the car). Whenever one of the lights comes on, i simply keep my old rds radio in my garage, and i pull the extension cable (which i have tucked under the dash) plug it in to the old radio and BAM the lights are reset. when im done i put the plug right back where i had it stashed. One thing to remember is if you do it my way (without actually relocating the RDS) you WILL loose you're chime system. But as i had mentioned before this can also be a plus.

~Good luck!