Sirius Satellite Radio hookup problem

I recently installed a Sirius Satellite radio Kenwood Here2Anywhere plug n' play unit in my suburban. I have a stock radio, so I had to use an FM Modulator to get the signal to the stock radio from the Sirius Reciever. There is a lot of alternator noise now when the sirius unit is on. I am sure that it is coming from either the Sirius unit, or the FM modulator or both, since they are both powered by 2 cigarette lighters (more likely to have alternator noise than other power sources). I purchased an inline noise filter to put on the power wire to the cigarette lighters. Would it be easier to put it on in the interior, right behind the lighters, or under the hood in the fuse block? Does anyone know the color of the hot wire to the cigarette lighter is on a 2000 Suburban? Thanks

I have a 2002 Chevy Suburban. I just installed the same unit. I have the factory installed AM/FM/CD radio with the slave cassette player. If yours is the same type you could try doing it this way. I tapped into the line going to the center console rear power port (red line - hot). Everything is working fine, noise free.
If you have the AM/FM/Cassette unit with the slave CD unit there are after market auxiliary cables (pie.net) available for playing your Sirius Tuner through the CD player instead of the FM modulator.
Hope that helps. I'll let you know if I come up with something better.