Hey I recently bought a Sirius radio for my 89 240 and installed it and all that good stuff and turned it on and it sounded GREAT. Then i actually started my car and noticed it was making that fuzzy bad signal type sound. So when my car is off and i only have the key turned to have the radio on the reception is PERFECT on it. When i actually start my car and turn it on it is fuzzy. At first i thought it might be a weak signal or something until i noticed that the amount of fuzzyness changes with RPM's. When my car is at idle there is a little bit of fuzz but as i drive or just rev up the car a bit the fuzzyness increases with the RPM's. So i thought at first that it might be a bad ground from my cigarette lighter so i checked that and even spliced another wire into it and bolted it to the frame, still same problem. So then i thought maybe the power coming into the lighter was not a very good current, so i ran a wire from my stereo fuse in my fuse box straight to the cig. lighter and still the same problem. It seems the fuzzyness directly goes with my spark plug spark. Because it kinda goes no fuzz-fuzz-no fuzz-fuzz, as the car is firing, which also explains why it makes more fuzz at higher rpm's due to the increased spark rate. Any ideas, comments, suggestions, or anything i might be able to try to fix this is greatly appreciated....its really gettin on my nerves lol. ALSO: my regular radio works fine, its only messed up from the sattelite radio signal for some reason...

 

UPDATE: Now its doing it with regular radio stations also...tried messin with radio ground still no luck

 

that's engine noise your hearing. normally it happens if you have a 4 ch. amp, and the rcas are too close to the power wire. do you happen to have a 4 ch. amp hooked up? you can check online if you can find a "power filter" that you can hook up to your constant and accessory power from the radio. and the fuzziness from your sirius is caused by the "over the air signal" it transmits to your radio. the the fuzziness happens due to strong signals from fm stations around the bay, electric towers, even tall buildings. one way you could fix that problem is to purchase a "direct connect" from circuit city, best buy, fry's electronics etc. the way it works is that it's a module that your sirius connect to, then it has a female and male antenna connection, so you can plug your antenna to it then back to your radio. helps out big time. hope this helps out.

 

It HAS to be a problem with the ground. Did you try grounding the radio ground directly to the body without running it to the cigarette lighter ground? Also, is one of your plug wires arcing to the body?