I had to be jump started recently due to a defective battery less than a year old. And now ever since, the heater works when it wants to. The fan blows fine, but half the time it'* cold air. I can crank it up to 90 and 'sometimes' it'll get kinda warm. I've noticed tho, if it'* above 50 degrees out...then it blows warm (again sometimes). Anything below and guranteed it'* cold air. I've searched and found nothing else here with the same problem. Maybe someone can shed a lil light...and maybe some heat?

Welcome to Bonneville Club. Please turn off bold font - kinda like CAPS - perceived as yelling. Some possible causes for no heat include low coolant, thermostat stuck open, plugged heater core, air-mix door (flap in air duct) not allowing air flow through heater core.

1. Check coolant level in radiator when cold - should be to the top.
2. Check coolant level in overflow tank.
3. Is engine temperature normal?
4. Are both heater hoses hot?
5. Check function of air-mix actuator.

Here is an article on how to fix lots of heater stuff including air mix actuator and photos: http://trialsnuts.com/ecc.pdf

Here is how to get warm in a hurry using a redneck fix for the actuator: http://www.bonnevilleclub.com/forum/...ic.php?t=41963

It seems We have had several members that have had airmix actuator problems after reconnecting a battery, and since you indicated that this happened after the jump start, my first thought is that the actuator has failed, like Bill has mentioned above.