I was driving today with a/c on and radio blaring.  Next thing I knew the radio sound is off and also the a/c stopped blowing and electric climate control unit display is blank.  Radio still shows time, and when you turn it on shows the light about the radio presets but no sound.  No air flow coming out.  It's a hot day out here, help!

Picked up a multi pack of fuses from the auto parts store before I got home from work.  Using a light found out CTSY fuse 15a had blown.  Using my Corvette ETM I found that this a pretty busy fuse.  It provides protection for a multitude of interior lamps (approx 12), heater/ac assembly, amplifier relay, cigar lighter, and antenna relay.  I put in a new fuse and my A/C is back on .  I turned on the radio and pop goes the weasel... I mean fuse.  So... I've come to the conclusion that because the fuse is fine until the radio is turned on... perhaps my antenna relay or amplifier relay are my culprits, with my inclination leaning towards antenna... but I really don't know.  How are you to check a relay besides just changing them out?  Anyone have an answer?

Unplug the relay(s), and see if the fuse pops. If it does, then your problem is most likely internal in the radio head.

|UPDATED|7/25/2013 7:28:00 PM (AZT)|/UPDATED|

The CTSY fuse powers the bose speakers through the relay. The relay coil itself is powered by the RADIO fuse. So if the CTSY fuse blows when radio is turned on, one of the speaker/amplifiers is bad/shorted.  Its not the relay itself, its one of the speakers it controls.

The power antenna relay is under the reveal panel across the rear inside of the car, with the hatch open. I don't know if (the FSM doesn't show one either) there is a connector at the base of the antenna under the car that you could disconnect to test whether its the antenna. If you don't want to cut wires, you'll have to access the relay and unplug it there.

My inclination is to suspect that there is one bad speaker/amplifier.

|UPDATED|7/26/2013 8:16:37 AM (AZT)|/UPDATED|

So it sounds like the antenna or a blown speaker then right?  I just had the fuel pump replaced, think they could have damaged the antenna wiring causing a short?  I took apart the speaker on the driver side rear as I thought I heard something popping back there, but a new fuse still blew regardless of that speaker being unplugged - hence my thought the antenna wiring or whatnot being the bad guy.  So sounds like I need to dig deeper and get to the antenna...

Oh, no...just as you got done dealing with the fuel pump.  Hopefully this will turn out to be an easy fix for you.  

Did you ever figure out what the issue was?  I'm having similar symptoms but I didn't get there the same way.  In your case you were driving and playing the radio and it went poof, and no sound and the display on the climate control went blank.

Well I totally lucked out on this one.  I got out early today to start troubleshooting the blank display on the climate control head and was planning to check all fuses as well as make sure that power was getting to each fuse.  I started with fuse #1 (the one I had pulled while I worked on my all-day project yesterday).  It checked good, just as it did last night.  But I also checked the voltage across the fuse terminals expecting to see 12v (i.e., 12v on the input terminal of the fuse socket and 0v on the output side of the fuse socket).  It initially read 12v approximately but as I checked it again several times it eventually read close to zero volts (0v).  I checked again several times to make sure I was getting good contact on both terminals of the fuse socket and sure enough I was, and the reading was about .5v.  I couldn't explain why it read 12v initially and now only half a volt.  But I thought WTH so I reinserted the fuse and thought I would check to see if this strange reading made any difference in the HVAC head unit.  (Now, it may not be important but I did notice when I inserted the fuse, that I saw a very small, I mean small spark as I inserted the fuse into its socket).  So I turned the key to start her up and voila, the climate control was displaying normally with the outside air temp displaying as it should and a green light above the AUTO button on the control panel.   Air was blowing out of the vents, so not sure exactly what happened but now it was back alive and behaving normal!  Doing the happy dance here because I was not looking forward to getting up under the dash to pull out the HVAC programmer or messing around with soldering capacitors (or paying someone else an arm and a leg to do it).  So at least for now I got away with one.  

Let's hope the OP has solved his problem.   He hasn't been on this forum since April 2015.

|UPDATED|3/6/2019 8:36:18 PM (AZT)|/UPDATED|