2001 Sonata 4 cyl. heater problem.

We are experiencing a loss of heat after driving 45 minutes. The dealer can't find the problem. Any similar experiences out there? Any correlation between using the wipers and the heat problem.

Reply to
ROCKSROCK
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Have you replaced the thermostat? That's the most common cause of heating problems.

If your car has an electronic heater control module like the newer cars do, that's also a likely culprit, especially if the heat works initially, then malfunctions.

Reply to
Brian Nystrom

Improper coolant level, clogged heater core, thermostat stuck open. Many possibilities. Has your dealer ever been able to experience the no heat issue? If not, you may need to provide specific instructions as to how they can duplicate. Does it tend to happen to you on a particular stretch of road? What type of driving are you doing when it occurs? Try to give as many details to your dealer as you can.

Reply to
hyundaitech

The heater cuts out in inclement weather while we are using the windshield wipers.

Reply to
ROCKSROCK

Do you mean that the blower stops or that the air becomes cold?

There's no link between the heat and the wipers, but it's theoretically possible there's an electrical issue affecting the wipers and blower.

Reply to
hyundaitech

The blower works fine but it blows cold.

Reply to
ROCKSROCK

I'm pretty much at a loss. There's just about zero connection between the wipers and heat. It would seem that if the dealer can make it happen, they should be able to figure it out while it's happening. Sorry I don't have more to offer.

Reply to
hyundaitech

If it's blowing cold air, it would seem that it would have to be a problem with the heater control module. Perhaps it's not be reading the setting on the temp dial and consequently it's not opening the valve on the heater core. I don't know how that would be related to the wipers other than they're both electrical issues.

Reply to
Brian Nystrom

I haven't yet seen a schematic for a Hyundai, but my Chryco minivans have several common ground points where several circuits come to a common ground. If one of these connections gets corroded between the wire terminals and the chassis or comes loose from the chassis, one circuit will be trying to use the other circuit as the ground path. This can cause seemingly unrelated circuits to "crosstalk" and have weird things happen. Maybe Hyunday doesn't use such a wiring architecture, but it almost sounds like this.

Matt

Reply to
Matt Whiting

If you've got the auto controls, what Brian describes is possible. If they're manual, I believe the heater door is vacuum operated.

Reply to
hyundaitech

Does the Sonata use similar controls to those in the Elantra? From what I understand, the '01 and up Elantras all have electronic controls, although they changed somewhat in '04.

Reply to
Brian Nystrom

I'm not sure whether they're the same. In fact, you're making me question whether I was correct on the vacuum operation in my earlier post. The manual climate controls are so trouble-free, I'm not sure if I've ever had one of the newer ones out. I suppose the way to check is to go to the schematics and have a look around.

Reply to
hyundaitech

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