I have problems with the third tail light , the back up lights, and the license plate lights not working on my 95 ford escort LX

Have you checked the breakers/fuses?

That sounds more like a bad ground.
Those circuits share a ground:
G401 (Hatchback) , Center rear of cargo area
G401 (Sedan) , RH rear corner of luggage compartment
G401 (Wagon) , RH rear of cargo area
G402 LH rear corner of luggage compartment
Look for clean solid connections that are free of corrosion. Follow the harness all the way to the lamp to make certain that the wire didn't get broken or a connector pulled apart.
I hope this helps.