Plymouth Sundance 1989 - problem with heater

[BLINSEY]

After My Car Warms Up ,i Turn On The Heat And It Blows Out Cold Air.

[Chriznat20@msn.com]

Well, there could be a couple of issues here.

Lets start with the basics. Is the anti-freeze level full?

If so, I would take hoses off the heater core at the firewall and flush one side out with a garden hose on FULL pressure. Then go and flush out the other side. A bunch of sediment should come out.

If that doesnt work, verify your model sundance (anything before 90) has a heater valve. It will be a gnarly looking contraption right at the firewall attached to your heater core hoses. These go bad and can get stuck in bypass mode. If you do have a heater valve, try removing it all together and see if you have heat. If you do not have a heater valve, lets move on to the next steps.

Take off the fascia around the radio and heater controls. There are 2 screws holding in the HVAC controls. Take them out and pull out the HVAC head unit. Verify that when you turn the indicator to hot, that the cable and apparatus are moving. Likewise, make sure the cable is moving the heat blend door, of which you might be able to see through the hole where the HVAC was, or you might have to get down on the driver side floor to see if it moves when you slide the indicator.

Those are the cheapest and easiest solutions.

You say that your car "warms up", so your thermostat is likely functioning, but maybe you or somebody else installed a lower operating temperature t-stat then what your plymouth calls for. I had a 185F in mine when I bought it (used), I promptly switched it out for a 192F model. Slightly better mpg's, and some better heat too.

A lot of the time when you have no heat in a 2.2/2.5l Chrysler engine, its because air is in the cooling system due to a bad head gasket. But you'd likely be overheating if that were the case, especially if you have no heat at all.