91 caravan heating trouble

hi i got a 91 caravan that don;t want to let out heat till you have been driving for 30 mins+ and will only blow warm air after that from the foot position anyone have any ideas of what could be rong????

thanks rod

Sounds like a thermostat that's sticking open and needs to be replaced. Thermostat and gasket cost under $5. It is located on the engine, at the end of the top hose under the gooseneck.

Rod, have the same exact problem,were you able to figure it out, i haven't.

hi Y & W,
first check for low radiator fluid level. If not that, put thin cardboard over front of radiator. Use two strips one for each side. If you get adequate heat with cardboard then thermostat is bad. it"s easy to replace with screwdriver, socket wrenches and scraper. do not use silicone base sealant on gasket as it can contaminate oxygen sensor. use new gasket. make sure new one has air vent hole.

Qwester thanks for that info,will give it a try. i already replaced the thermostat,flushed the core, checked the heater control vavle, the cable to the door, and fluid, also no bubbles. so stumped.