OK so this is kind of strange but when my lights are off it shifts great it has the over drive trans. It can be hot cold day or night but when my lights are on it stays in 3rd gear and will not shift out even at take offs.but as soon as I shut the lights off it shifts fine

Any idea what could be going on
I have already replaced the ground.vss.neutral safety switch.sensors
Trans filter n fluid cleaned connectors etc


Help!!!!!!

 

Not saying there couldn't be a problem with the trans section, but a good part of the time when a poor ground connection exists in a system it can take a completely different path to complete it's circuit and crazy things happen. Suggest you try cleaning all the grounds you can find especially those up front near the headlight area. Then also check all the connection plugs that go to the trans. If one of the grounds there is poor the trans signals will find another path. Many times a wiring diagram will help to show what circuits share a common ground. There are several ground wires that connect the sheet metal to the engine, trans etc. Without a diagram and location of these ground locations a good visual tracing of ground wires will help.