BillH

1997 F-150 XLT. The air conditioner works great, but the heater works intermittently. I get little or reduced air flow in the heat mode and the air is warm at best. I suspect that the internal damper is not working properly, but need troubleshooting help. Where can I get a good air flow diagram and physical drawings or pictures. Thanks for the help in advance.

presto666

bill, i know its kind of simple, but did you check the coolant level? or maybe theres air in the core/small heater hoses? i had this problem (my small hoses arched higher than the cap and i had luke warm heat) I tied down the hoses, parked on a steep hill backwards with the cap off to let the air escape. it works great now.