For the record, I'm new here but not at all to forum etiquette or cars in general. I searched and came up with some very old threads but nothing with any answers or resolutions... When I figure it out, I'll post the fix here so future searchers can help themselves.

I just bought this 2000 TL with Bose last week and have fixed a million things (that's a story for another day) but the last thing I have left is the subwoofer. The previous owner has installed a new head unit solely to have Bluetooth streaming but no other mods otherwise. The subwoofer just makes a low hum noise regardless where the volume knob is but cant actually play any music. I unplugged the little harness in the trunk that leads to the speaker itself and the hum stops, plug it back in, starts humming again. Would this lead to say the sub is blown or something from the head unit install has disrupted the signal? I'm very mechanically inclined under the car or hood but subs and boxes have never been my thing. Where should I start probing with the volt meter to check whether its the amp, sub or head unit? Thanks in advance! I hope I can be as helpful as I am on all of the other forums once I get more familiar with this car!

 

Welcome to the Forum!

From your description it sounds like there is a Ground Leak somewhere... In order to use an aftermarket HU with OEM Subwoofer the installer had to Hardwire the RCAs from the new HU into the High Level input from the SUB AMP (The Subwoofer AMP is located behind the rear passenger seats, specifically behind the RIGHT Passenger Seat) so maybe he didn´t insulated the wires and they have come apart and its touching the chassis.. Time to dig around the passenger seats to see what is going on, If there isn´t a problem there then you will have to remove the Aftermarket HU to see if the RCAs aren´t chassis grounded... The TL is very picky with these things.

 

Ok great, gives me something to start digging into! Thanks