You revert PIC voltage PIN... VSS= Ground VDD=5Volt And now your PIC is probably burn!!!!

+ you can't connect two 7805 output together...

1000uF at the output of the regulator is unusefull. Can be good to place them at the input (ignition switch). at the output i suggest 10uF(tantalum or 47uF electrolitic) + 0.1uF ceramic.

I'll also suggest to tie to ground unused input to avoid electric interference from any external car noise(common CMOS handling... also avoid to burn PIC). Be sure of your TRIS define for the unused pins... must be set as input.