Hey people. A couple of months ago I had a Volvo radio reinstalled in my 740GLE. It was used and a bit wonky but good enough for my purposes. Last week I had the alternator rebuilt. When hooked up to a voltage meter the output jumped around between 9 and 14 volts causing an unpleasant pulsing in all the lights. The rebuild fixed that. However, somehow the radio has gone from wonky to pissing me off. The AM radio reception, while always bad, is now obliterated by caustic static. But here's the thing, the static changes pitch following engine speed. In neutral, with the radio volume up, I rev the engine, only the pleasing Volvo whir is overshadowed by scary-50's-synthesizers-dying noises going up, then down. And tapes have static cutting through at any volume peaks. Now I like driving through rural small towns in my Volvo blasting Slayer like the next guy, but this is too much. My questions: Is this a bad ground? If so, is it at the radio end or at the alternator? Or is the head unit I put in crappier than I'd like to admit? Any help would be much appreciated.
-Gourdy