I had a problem like this on my 99 GTP and I was cursing it for a while because everytime I went to touch the light to fix it, it would come back on again it would work for a while until it decided to die again. It ended up being a nick in the wire about 1 foot back from the headlight connector. The nick ended up corroding to the point of on a spot of rust making the connection. After fixing the wire, no more problems.