I Have 91 Dodge Caravan With The 3.0 Engine .geting No Heat.
Posted in Air Conditioning | Asked on Jan 29, 2012
I replaced the broken thermostat that was in two peaces.The AC compressor power was disabled 2 years a go when the pomp stated to knock.The heater worked fine tell now.Last summer the belt to the AC was removed to save gas.could it still be the missing belt that could be cosing the problem?The fans are blowing air throe the vents.I can switch the flow of air from the heat vents to defrost.And when I poul the lever for the blind door,I think I can hear it moving. Should I pout the AC belt back back on?
There are 6 Answers
The ac has nothing to do with it. the 3.0 had trouble with bleeding air out of the system. be sure the coolant jug is up to the full mark, drive it 5 miles and check it again.
Its unlikely to be the belt as the pump has been disabled. The heater relys on hot water from the engine and once at operating temperature should start to pump warm water into the heater core. If the blend door is opening and closing letting air pass over the heater core then the problem may be a blocked heater core or a broken heater valve. To test this you need to locate the feed and return water pipes to the heater box located on the firewall inside the engine bay, if you disconect the return line and run the motor (only quickly) you should see water warm water pass through the core if it is unblocked. The other potential problem could be a broken valve usually located in the water pipe feeding the heater core, have someone change the heater from hot to cold and make sure that the valve is moving otherwise it wont allow any hot water into the heater. And the only other problem (worst case scenario) is if you have a slight head gasket leak it can pressurise the cooling sysytem disrupting the flow of water through the heater box, the easiest way to check this is to start the engine from cold without the radiator cap and top up until full, if you rev the engine and lots of bubbles rise up through the radiator and it starts to push the water out you may have a problem, if you rev the motor and the water level dips slightly and then returns to normal (a little overflow is normal) then everything is ok. Good luck chasing it down because It sure sucks having to wear three jackets in the winter to keep warm
The problem is most likely the heater control valve. It is located under the hood on the right/passenger side near the heater control box. If the valve sticks it will not allow warm coolant to flow through the heater core. This parts purpose is to stop heat from entering the heater control box when the AC is on. This valve usually costs about 25 bucks and takes about a half hour to replace. Hope this helps. Christopher
Heater Control Valve
Your heater could be burned out.
The vacuum hose going to the heater control Valve is not working
Check your thermostat could be broken and the water is just keeping the engine cool so u cannot get any heat