Issue with head unit...

Hey TW, I was wondering if you guys could help me out? I recently installed a JBL touchscreen head unit into my 2006 Toyota Tacoma. It has worked perfectly fine for the past couple of months, but now it is alternating between the front speakers and the back speakers. I was wondering if anyone could tell me how to go about diagnosing the problem and how to fix it?

 

My first thought would be to check the wiring. Take out the head unit and re-press together any connectors and wires connected to pins within each connector. If it's alternating perfectly - like front plays only while rear is off, then rear plays only while front is off - then it makes me think something might be wrong with your HU internals. Like software or hardware. Do you have the capability to reflash the HU?

About a year ago my HU was giving me problems with controlling my iphone. I reflashed the firmware and the problem went away.

 

Thanks for the info! I did find out that it isn't actually alternating. The from speaker periodically cut out, but it seems like the timing is the consistently the same.