This has happened to me twice. I always remove the faceplate after turning off the engine. When I get into the truck first thing I do is intsall the faceplate then I start the truck. Normally I hear music playing before and after I start the truck, but yesterday no sound came out of the speakers. No matter what I did, checking all fuses options or setting etc. there was no sound coming from the speakers. This lasted the whole trip (1.5 hours).

I removed the faceplate as I always do after I got to my destination. When I came back to the truck after about 1 hour installed faceplate started truck I could hear music coming from the speakers.

What could cause no sound from spaekers? Is there an option or a setting I need to do?

Everything seems to work except no sound.

What kind of truck is it and what year? Where is the brain located.

I have a 2000 Ford Excursion and the brain is mounted in the dash under the avic-n3

I forgot to mention its been installed for 6 months and working perfectly until 2 weeks ago.

If it was working properly for that long, I'd lean toward it being a bad speaker in the truck. Basically when one of the speakers starts to go, the amp inside the brain will read the speaker as a short circuit. When that happens, the amp will shut itself down to keep from frying. Try testing the speakers at the radio harness. You should get between 4 and 8 ohms resistance between the positve and negative wires. Also make sure you don't get continuity to ground on any of the speaker wires.

Thanks for the info. I should mention I installed JL audo speakers xr570-cxi about 2 months ago. They have the separate crossover network. I wonder if that could be shorting out? I'll check this out over the weekend. Thanks