Here's someone else who had a similar problem and the solution they found:
from the Q and A forum for the 94 Maxima:
Meguiars is reviewed pretty well. Armor is known for causing problems with valve stems.
Reviews of Meguiars:
brake sensors are either located at each wheel or in the differential. You should be able to find out where in the owners manual. At some point in the near future driverside will be posting owners manuals on the site. Here's a link for the Montana trim owners manual (which I assume would work for the SV6):
It is probably just old and so long as it is not too bothersome it would not be worth repairing or replacing. The stereo on my volvo also would go dim and the tap deck eventually broke, so I ended buying a new stereo at bestbuy for around 100 bucks.