Sounds like a wiring problem with how you installed it, or the new car.

It wouldn't just pack up from being swapped between two cars.

 

If any of the speaker outputs are grounding or touching each other it will turn off the internal amp to save itself, check wiring first i reckon, or trry it on a m8s car to double check....

 

well there was a pioneer head unit in the car when i bought it, which i removed and put my 'old' one in. gave it a test and got the no volume problem. so ended up putting the original unit back in and worked fine . does anywhere repair head units without having to send them off?

 

It'll be the output chip on the back, underneath a heat sink - I had one with the same problem - audio repairer wanted £70 to repair it, I tried getting the chip myself cheaper, but it was all loads of hassel so I didn't bother in the end and got a new one. Try runing it to an amp thru the pre outs, they should still work fine and you'll be able to run the speakers of the amp :beer:

 

Have you looked through all the settings on the headunit? ie if there is a menu that switches the speaker output off in preference to RCA's? Or is it faded all the way to the rear (and the car has no rear speakers?)

Think about it for a minute, it's not just going to break like that.

 

make sure the brown wire comining from unit isnt connected anywhere as this usally is phone mute 4 the set and if connected it tells the set 2 switch volume off

 

Failing everything just wire it up to 12V and get a spare speaker and test every output.

Andy

 

thanks for the info ill give the suggestions a go, and let you know how i get on.:beer:

 

You could make me an offer on this
http://www.migweb.co.uk/forums/items-sale/344848-pioneer-deh-p7700mp-cd-player.html
I could meet you somewhere too if you like