I have a stereo kit that my wife bought me for x-mas last year and I find that I can not turn up the volume or the HU turns itself off! It comes back on but if I do not turn down the volume it just shuts off again. It came as a kit so I assume that all pieces should be compatiable? The kit is a Sony X-PoldCXS-GT08HP which contains a CDX-GT08 45X4 HU, 2 6.5 2 way 190w peak 40w rated 4ohm and 2 6x9 300w peak 60w rated 4 ohm. What could be causing this?

 

You have a short somewhere.
Usually at the speaker.
Disconnect each speaker, one at a time, and test.
Disconnect LF, turn up volume, reconnect LF.
Disconnect RF, turn up volume, reconnect RF.
Disconnect LR, turn up volume, reconnect LR.
Disconnect RR, turn up volume, reconnect RR.
While you have a speaker disconnected, and the volume turned up and the HU doesn't shut off you have found your problem speaker.
You'll find the short that way, fix the short and you shouldn't have anymore problems.

 

Depending on the vehicle as well it could be corrosion in the connector in the door boot. very common in VW's and Chrysler/jeeps

 

you know....ive had the same problem, when you use a head unit with alot of features it tends to draw alot more power than the stock wiring can provide. try upgrading the power and ground wire...like 10 guage, it works.