The Bonnet catch is perhaps one of the most simple mechanical devices on a car (i.e spring loaded catch) Pull and it releases.
If your's does not open there only a few things it could be.
a)The actual L catch is bent and catching as you pull it up, i'm afraid the only solution to this is brute force to pull it free.
b)One of the hinges or both are seized or bent, try spraying a little bit of WD40 on the hinges to lubricate.
Ultimately if when the cable is pulled you can see the latch moving, is it moving freely and all the way?
The first thing to do is spray WD40 all over the latch and hinges and pull latch at the same time as having a friend pull up the bonnet in a rocking type of motion i.e 1..pull...2...pull...3...pull... as this may prize it open.
The last thing to try is anything catching on the sides sometimes cars that have had a side impact the wing pushes against the bonnet, you should have a Clearence of about 2mm either side if not again just brute force is needed to open.
Hope that helps.
Aufo8mycow
Sean Marson, September 2006
