Amp interfering w/FM reception

Just installed a new head, sub and used amp in my 2003 Elantra.  I did everything in 2 stages: head unit on day 1 which worked fine then sub and amp on day 2.  When I fired up the complete system, the FM reception was absolute crap.  Pulled the fuse on the amp and boom, reception was great again.

Head: Eclipse CD5423Amp: Matts something or other (used in my 2 previous  cars)Factory antenna: located right rear of car.  Power down the left side of the car, signal down the right. I noticed the reception was slightly better if I covered the amp ground with my hand, so I made sure the ground lug and car chassis was sanded clean, but that didn't help.  I also tried to move the amp to the otherside of the trunk (the side opposite the antenna)... no good.  Right now, I've got a switch on the remote turn on so if I want to listen to the radio I can kill the amp (cheesy, but it works).

Any other things I could check?

Thanks

Try this. Take the radio's ant out. Then measure the resistance the outer shield of that ant to chassis ground. If the resistance is high, then you need to check the cable and make sure that the base of the ant has a clean mounting point.Certified Security Specialist

Always check info with a digital multimeter.

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