Why does my car squeal when the AC/Heat is on and why doesn't my horn work?

2001 Plymouth Neon





Last summer the AC/heat worked just fine. Since it is starting to get warmer I turned the AC on and the car starts to squeal, and sometimes feels like it is ging to die. This also happens when the heat is on.





I have also noticed that since this problem, the horn has stop working. Yet every once in awhile the horn will work. Are these two problems related?

Why does my car squeal when the AC/Heat is on and why doesn't my horn work?
don't think they will be related problems, the A/C problem will either be a loose drive belt or a problem with the A/C compressor
Reply:Check AC belt, sounds like your AC is trying to lock up being the motor in stalling when AC is turned on. The horn has a short.
Reply:The fan belt is slipping to make the squeal, tighten it, or put a little valve grining compound on the belt. It does it when the heater is on because some cars run the ac with the heater to keep the windshield from fogging up.


the other is probly the horn rely, located in the fuse box.
Reply:The AC automatically goes on when you turn the heater on. You need to either adjust or replace the AC belt. The horn is a different circuit. Just coincidence. Check the wiring around the column, and wherever the harness comes in contact with metal, eg, the firewall. Also check the wires at the horn. If it's not apparent right away, you'll probably have to take it to an auto-electric shop.





Oh, and check the alternator belt too. I've seen that as the cause as well.



tanning