I am installing a clarion nx501 in a 2011 gm 1500. I am using a Pac os-4 to retain the onstar and a swi-jack to retain the steering wheel controls. While reading the literature that came with the products, I noticed that it said in order to maintain the on-star on a system with aftermarket amps, you would need to wire an additional speaker on the front left channel.

I am aware that the reasoning for this is that the aftermarket amp will be run off of the pre-amp on the back of the radio. now my question is, is it possible to tap that channel and run it to the front left speaker? or will this cause a problem. does it have to have a seperate speaker?

 

Is the amp powering front speakers or subs. If its for subs and the speakers are running off the head units high output; I wouldn't worry about it. If the amp is powering the front speakers consider this. Sounds like the Manuel is saying that the replies from onstar (operator) will only play out of the high output(front left specifically) and not out of the pre outs. If that is the case I'd be suprised if it's true. Maybe it won't work in some head units and they're covering their butts. I'd try it normally first and if it didn't work I'd run a small full range speaker off of the left front high output. then place it wherever is convenient. Note I'm not experienced with onstar I'm just using my basic knowledge on headunits.