?? crazy Prism won't start

Hello I was wanting to know if anyone out there could help with us! We have a 90 Geo Prism that tends to act up. The problem is this we will be ok for a while then all of sudden the car won't start won't even try to start! No headlights or very dim horn very low I mean the whole car acts like its possessed!!! Now the first time this happened we replaced the headlight relay due to it was making some crazy ticking sounds!! Now since then it has happened again but this time when we shook the headlight relay and put it back the car started!!! Garages have told us to check ground wires or fuse links! We replaced the battery, alt, and starter!! I am so hoping someone can help us!!! Thanks!!
Tracy and Gene

hi,
I almost certain that the Garages were right!
I had the same problem , not with a Geo but with a ford .
Didn't wanna start even with a brand new Batterie and so on....
So i bought me a really wide Copper ground wire and Voila that did the Trick!
Now hopefully it will do it for you , too!

oups
P.S. i needed to drill a hole somwhere near the batterie to connect the Batterie with this new Ground wire.
P.P.S. ground problems are about 90% of all electrical Problems on a Direct Current Source(Batterie)