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Discussion Starter #1
The unit is brand new (pioneer avh-z2150bt) so 99% sure it is not a faulty unit, after driving maybe 20 mins or so it shuts it's self down for about 5 mins before powering back and and being fine for the rest of the journey. Does it pretty much every time and has always done it, bugged me but never made it to the top of the to-do list. Does it when it is hot, when it is cold, with aircon, with heating, with nothing, with very quiet volume or very loud volume.... so 99% sure it is not environmental.

Today driving it did it and I popped the top cover off the dash and the headunit is hot to the touch. Given I am sure it is not hardware, and it is not environmental that leaves wiring as the obvious culprit. Anyone any idea where to start looking?

The speakers and all wiring is stock standard on a 2008 T5. I earthed it to a solid looking screw into a lump of metal (excuse the poor mechanical description) inside the dash. Constant live is the standard live that was into the factory stereo. Switched live is piggy back fused from a switched live in the fuse box (cant remember which? wipers maybe? will check)

Thoughts.....
speakers +- wrong way around? They sound perfect and I got the colours form some post in here (again cant remember fully?, will have to check)
I am certain the earth is good..... but if not, could a bad earth cause this?
Could my choice of switched live cause this?
Could some of my wiring gauge cause this? (The only wiring I added was for the earth and switched live, both were very thick auto wire (maybe 4mm?)

I can pull out the radio and look but have not idea where to start on fault finding.
 

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In response to your thoughts: no - none of those should cause it to run hot.

The main external thing that can cause problems with overheating is if the speakers are the wrong impedance. The likely way for this to happen is if someone has added a second set of speakers in parallel with the originals - apparently not true in your case.

So the problem is probably internal. One question would be: does it have an internal fan, and is it working correctly? Where fitted, these are typically needed for the processor, not the power amp section, so a fault there would be largely independent of volume. Assuming it has one, the only way to find this out would be to put it on the bench, power it up and leave it for a while and see if it cuts in correctly.
 

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Discussion Starter #3
In response to your thoughts: no - none of those should cause it to run hot.

The main external thing that can cause problems with overheating is if the speakers are the wrong impedance. The likely way for this to happen is if someone has added a second set of speakers in parallel with the originals - apparently not true in your case.

So the problem is probably internal. One question would be: does it have an internal fan, and is it working correctly? Where fitted, these are typically needed for the processor, not the power amp section, so a fault there would be largely independent of volume. Assuming it has one, the only way to find this out would be to put it on the bench, power it up and leave it for a while and see if it cuts in correctly.
Thanks for the advice... I am reluctant to believe that it is internal because it was out of a brand new sealed box, However if I don't get any more ideas on where to check in the wiring will follow your advice, pull it out and try your suggestion.

My gut feeling is wiring as there are some other posts floating about where wiring one way or another has caused the same issue. Just don't know where to start looking.
 

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Hi, I'm not an auto electrician but this is something I've picked up over the years. if the head unit is high power then it will pay you to run new speaker wires from the head unit to the speakers and bypass the factory fitted ones, it should stop your head unit over heating. Apparently the speaker wires that run in the loom are somehow earthed somewhere which causes the overheating. An easy way to check your speakers for being "out of phase" is to connect 2 short lengths of speaker wire to the speaker terminals, touching one of the wires from the back of the speaker to the negative of an AA battery. As you touch the remaining wire to the positive end of the AA battery the speaker cone should move "pop" towards you, if it doesn't change the wires around until it does. The wire that makes the speaker cone move towards you is the positive wire. Hope this helps. It might pay you to run new speaker cables straight to the speakers from the head unit to see if it helps before routing them through your dashboard etc. Steve
 

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Discussion Starter #5
Hi, I'm not an auto electrician but this is something I've picked up over the years. if the head unit is high power then it will pay you to run new speaker wires from the head unit to the speakers and bypass the factory fitted ones, it should stop your head unit over heating. Apparently the speaker wires that run in the loom are somehow earthed somewhere which causes the overheating. An easy way to check your speakers for being "out of phase" is to connect 2 short lengths of speaker wire to the speaker terminals, touching one of the wires from the back of the speaker to the negative of an AA battery. As you touch the remaining wire to the positive end of the AA battery the speaker cone should move "pop" towards you, if it doesn't change the wires around until it does. The wire that makes the speaker cone move towards you is the positive wire. Hope this helps. It might pay you to run new speaker cables straight to the speakers from the head unit to see if it helps before routing them through your dashboard etc. Steve
Thanks Steve, that is actually really useful. I did read another post somewhere with someone saying they fixed an overheating problem with exactly that, and that the factory speaker wires were too small diameter. Need to add it to the jobs list and wait for a day when I have the time.... Maybe a task for self isolating time.
 
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