j-wigg

does the heater core need to be hooked up for the a/c to blow through the front vents? currently have a bypass hose on the hard water line.

86 5.0L

no, you have a vacuum leak, check the line on the vacuum tree marked A/C

j-wigg

i'll have to check the vacuum measurement again. thought all was well last time. replaced the hose from the ac on the vac tree to the ac tree on the psgr side of the firewall. thanks for confirming about the heater core hose. i was thinking a possible switch issue.