when i start the engine the a/c works fine when i start down the road it goes to heat i replaced the vacuum lines from the manifold to the vac reservoir the vac check valve is working the vac pots all work even going down the road

 

Does it go to heat or does blow out warmer air? Sounds similar to what mine was doing and it was due to the air gap in the compressor clutch being out of adjustment.

 

do you know what the spec for the gap is thanks

 

feels like heat i will put a thermometer in the duct and take a test drive