So, just got my '05 back from the dealer with no real resolution to this problem (that they had never seen before):
When the morning temperature is below freezing (as it has been for weeks here near Philly), at first start up I get an extremely loud "exploding" sound through the speakers. Sounds like an atom bomb's been dropped in the car. Matters not whether the radio is on or off. Lasts for just a couple of seconds. Does not happen on subsequent start ups the rest of the day - until the next morning.

In speaking with Mazda support, the dealer says they mentioned first a weak battery as a possibility, but that did not do it. Then they offered an exchange on the radio (for about $250 installed), but also the possibility that it's in the power amp.

So, I'm thinking the radio swap wouldn't matter much, since the problem happens radio off or on, and the power amp is a separate unit isn't it? If anyone has any thoughts or experiences along these lines, any info would be appreciated. How tough is the power amp to get to and check out?

Thanks much!

 

More info needed....BOSE or no? Any aftermarket installed items? Stock ignition?

 

Bose yes, other than a K&N Intake, everything else is stock.

Thanks!

 

It could be many different things. Don't pay Mazda anything unless they know it will fix the problem. I would hate for you to pay them to swap the HU only to have to swap the Amp.

If it were my car The first thing I would check are the connections. Physically unplug them inspect for damage and corrosion then put them back on and see if the problem is fixed.

There are many good dash dissemble instructions on this Forum check them out before taking anything apart.

 

Thanks - I was going to check all grounds and such, so I'll add the connectors to the list. Agree with you on the first part - they don't seem to have a definitive answer, so I'm not going to pay the heavy price for trial-and-error.

Thanks again for the thoughts.

 

Hey no problem. Make sure you are checking the connectors on the back of the HU. Post up your outcome to the rest of us! Good luck

 

Because of the brutally cold weather recently, I have not been able to do the connection/grounds check. So this morning when I went out in 2 degree temps, i expected to hear the usual audio explosion upon startup. But nothing! Hmmmm... Then I realized the sound out of the radio was pretty tinny. Checking the fader, I noticed was I was getting precious little sound at all out of the rear speakers. So, does that likely mean the power amp for the rears gave up? Is there an available schematic or on line manual to see where all that stuff resides?

Thanks!

 

Once again it could be many things and the amp is not at the top of the list of things that could be bad. Once again check all your connections. Its not enough to just look at them you really need to take them off and reconnect them to ensure continuity of the mating surfaces.

Without seeing a schematic of Bose wiring I cannot tell you where Exactly to look. Check all connections not just on the back of the HU but also the AMP.