Help! RS Flash Tron II Trouble

[F-100CuStOmCaB]

OK, so I am trying to fix this car for someone but he said that if I can't it's no big deal.

So heres what's wrong with it, it doesn't go forward, did go backwards for me but just messed around with it again and now it doesn't even do that. And then I noticed that some times the steering would turn one way without even touching the remote and it will keep it turned the one way for a few seconds and center out.

Also when I pull the trigger for it to go forward all it does is click.

Anyone have any idea what is wrong?