Trouble installing a JVC kd-g 401

Hello, I'm having some trouble installing a jvc kd-g 0401 into my girlfriend's car (a 1995 Seat Ibiza). It comes on for about 5 seconds then switches off. The fuse doesn't appear to be visibly affected, and it starts up every time, but I can't get it to stay switched on. Any suggestions as to what the problem might be, or what I could do? I'm basically a beginner to the whole thing. Any advice is appreciated.

Check the ground c if its tight. Or check all your connections, i cant think of anything else, mayb it could be your deckPioneer Premier TS-w3004spl, Bass Slammer vented, Kenwood KDC MP-4028, and a KAC-9152d.

start the car up before you turn it on. you may be getting too low voltage (battery low) and make sure the ground is good.

Thanks for the replies. Just to shed a bit more light on the situation, my girlfriend's original car stereo (a Blaupunkt) still works fine when I put it back in (so I don't think its low battery or bad wiring). However I am using the wiring that was already in the car when I removed this Blaupunkt unit, same connections etc (I didn't see the point in changing them since everything was the same). Could this be causing the problem?

OK, problem solved. I had a friend take a look. Apparently the permanent live wasn't connected. It wasn't necessary for the previous system but was for the JVC unit. Thanks for you replies, I appreciate the help.