97 caravan (heat problem)

My 97 caravan having a heat prob,when i start it takes time to warm up but in 15 to 20 min heating guage gets to normal but as soon u drive needle start droping and u can feel that air is getting cold,and again if u stop for 10 min it goes back to normal.
can any one help whts the prob. thks

My 97 caravan having a heat prob,when i start it takes time to warm up but in 15 to 20 min heating guage gets to normal but as soon u drive needle start droping and u can feel that air is getting cold,and again if u stop for 10 min it goes back to normal.
can any one help whts the prob. thks

Sounds like the thermostat is shot. Try changing it with a good quality one. Should open up around 190 degrees. Also check to make sure the radiator coolant is at the proper level. Low coolant will also affect the heat.

Sounds like the thermostat is shot. Try changing it with a good quality one. Should open up around 190 degrees. Also check to make sure the radiator coolant is at the proper level. Low coolant will also affect the heat.

Forgot a simple thing to check! Make sure the radiator cap is in good shape as it needs to hold the pressure for the system to work!

thks for reply,i ll check

I agree with racenut, it definetely sounds like a thermostat prob.

thks guys,yes it was thermostat problem.fixed now.
thks for help,HAPPY NEW YEAR