I have a strange problem with the electrical system. The voltage (ie. head light intensity, interior light intesity) vary/cycle up and down at around 3 or 4 times a second. It looks like I'm trying to signal someone while I'm driving. Sometimes the varying is worse than other times. I can't seem to link it to anything (eg. fan on or off, A/C on or off, radio on or off, turn signal, weather, etc.). When it is bad, the radio cuts in and out - probably due to the varying voltage.

I had my electrical system "checked out" at an auto parts store. This is the alternator check that a parts store can do in the parking lot. This test showed that the alternator is OK.

I have 57,000 miles on the car. This began probably around 48,000 miles and has been happening more frequently. It doesn't keep me from driving yet, but it is annoying.

Anyone run across this?

 

if you have a sub it could be your amp

 

Thanks for the comment. No sub - std Bose system.