I have a 2002 Chrysler Concorde I bought a little over a year ago. Recently the heater blower has frozen after a night of freezing rain/sleet. This has happened twice. The first time the fan started working again after the temperature got above freezing for a day. A very small amount of heat still comes out of defroster because I can see it having a effect on the foggy window. But the fan will not blow at all. It is currently frozen for the second time. Extreme cold temp don’t affect it but freezing rain does. How can I prevent this in the future? Thanks.
Have someone check the condensation drain tube for the A/C system for blockage.
Normally this tube allows water to drain from the vent system when the A/C is used. But if water is able to accumulate in the system without being drained it can reach the level where it can freeze the fan when the temperature drops below freezing.
the temp has gone below freezing a lot of times with not problem but only when freezing rain does it happen.
Are you sure you don’t just need a new blower motor? If it is freezing, I’d crank the heat up to high–leave the fan off though–and let it cook for an hour or so idling. Periodically try the fan. If you just leave the fan on while it isn’t turning, you will probably either blow a fuse or damage the motor, or both. Any chance of parking it in a heated garage for a while?
The cowling at the base of the windshield (under the hood) probably has drains on it for rain water and such. The fresh air intake is also probably near it on the passenger’s side. If the drains get clogged up you can end up with water getting into the fresh air intake - or at least I assume that’s what has happened to me in the past and resulted in water getting into the area of my blower. I never had it freeze up but did get it leaking into the interior. I would check the drains at the bottom of the windshield and pull the blower motor to clean things up or you’ll end up with other problems as well (like corrosion).
Until you can get the drains fixed you might be able to stop the water from getting into the ducting by placing some visqueen under the wipers, all the way to the sides of the car, and about the middle of the hood area, using some magnets to hold it in place, when the car is parked outside. Don’t try to use the blower while it is jammed, you can damage things, which you may know already.
Ok, here is an update on what has been happening in case someone else has this problem:
the first time this happened I simply waited until the weather got up above freezing for a day or two and everything started working fine.
the second/last time this happened the blower refused to work for a couple of days while the weather stayed below freezing and then one day the fan came on full force while I was driving in below freezing weather. after that, the fan stayed on any time the ignition was on.
I can adjust the temp and the defrost/floor/vent setting, but the fan constantly stays on high, even if I turn the air to the “off” setting. that has continued for two weeks. the first weeks weather was below freezing but the second weeks weather has been in the 50’s. I had hoped it would straighten out with warmer weather, but now it looks like the condition is being caused by something other than frozen water.
If this vehicle has Automatic temperature control inspect the connectors at the blower motor power module. The connectors get weak and burn up.
You need a new fan switch. This is easy to check for anyone with a voltmeter. You may have other issues as well. But it’s likely that your fan wasn’t “frozen” to begin with. Or maybe it was and you have a water AND switch problem. There is also a resistor in the circuit and that should be checked.
From what you say I think the real cause of the issue is the speed control module for the blower has a shorted output due to the motor being left on while it can’t move. This causes excessive high current to flow which can damage the module and the motor. You may have to replace the motor also in time. If the module is shorted it shorts to power, not to ground, so full power is allowed to reach the motor. By following the wires back from the motor it should lead you to the speed control module.