the a/c switches from panel to defrost when i accelerate/ cannot find vacuum canister

You have a vacuum leak. check under the dash and the supply hose from the intake. There is no canister per se, but there is a vacuum check valve that could be bad. Based on what you described, there is a vacuum reservoir that does the same as a canister. I have attached a vacuum schematic to help identify the problem.

thank you i resceived the schematic but did not get a legend to go with it ( it shows ther parts but not description ) need the description to locate easier, thanks raul garza