Dash AC Weak

Yes, I have the same issue. On acceleration I loose AC from the dash. Came to find that when this happens all AC flow is diverted up via the defrost ducts due to a loss of vacuum. Which leads me to the cause. SQUIRRELS nested on top of my head over the winter and ate into the vacuum lines. Have now replaced sections of 3 lines and now have AC but am still trying to trace a vacuum leak avoids my detection.
Anyone know of a way to trace a leak with the engine off????

X2 on the vacuum ball(reservoir). Could have a leak or crack, causing loss of vacuum. Or, the line going from the vacuum ball to the engine, or vacuum ball to controls.

They are pretty cheap. Around $30 at any auto parts house.

Agreed-- start by checking for a vacuum leak-- the likely cause.

If none found, here is "Plan B": Does it have a vacuum reservoir? If not, add one. The reservoir will keep the vacuum to the dash HVAC even at full throttle, where the engine is not generating sufficient vacuum.

you have a pinhole leak in a vacuum line it is an evans tempcon system and hopefully it is all on the front wall.