Hello all...

I have a Chevrolet S-10 pickup with a four speaker audio system. The
speakers are factory installed Delco units, but the head unit is a Pioneer
cassette player. This truck and the speakers aren't terribly old...it's a
2003 model year truck.

What happens is very strange--and happens regularly, especially when the
weather is cold, some of the speakers appear to become open circuits. They
will not produce audio and tests with an ohmmeter show them to have infinite
resistance. But...if I turn the radio way up loud, the speakers will
suddenly start to work. Checking after doing so reveals that the resistance
of the speakers has dropped to about 4 ohms or so.

I know the head unit is working properly and all the wiring connections to
the speakers are good. But what would cause speakers to open up like this
and then start working again when the amplifier is turned up loud? I plan to
replace the speakers with new ones...

William