help with heater on a 97
 

my 97 s10 with a 4.3 dunno if that matters wont blow thru the vents ...only on defrost ,any help is apprecitated

Re: help with heater on a 97
 

sounds like you lost vacuum to the controls. defrost is the default position.
it feeds from the center drivers side of upper intake to a check valve between the booster and fender. there it branches off to the TX case, front axle actuator and another line leads to the interior. also make sure the hose at the reservoir is OK.

Re: help with heater on a 97
 

the resivoir hose was toast .....replaced it and it works thanks !