Take a good look at the pull handle. See if the lead plug has stripped off the cable, more than likely it has. If that is the problem you can pop the hood using a small set of vise grips on the cable end, until you get a replacement cable.
I got my replacement cable from FastLane for a song (also picked up a new pull handle too). Fairly simple replacement, but gets a bit tricky at the latch end, due to tight quarters. I had to drop the aux fan, plus you have to remove the latch mechanism to attach the cable end.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.