Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
My name is ***** ***** I am a professional here at Just Answer. I noticed that your question had not received a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.
If this is a horn chirp and if you have an after market component installed like a remote start or alarm system this may be an issue with the after market system at fault internally with the after market ecu/control unit at fault.I have seen this occur before and had to either remove the after market system completely to resolve this or re wire or replace it.If there are no after market components installed let me know.
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Is it the horn that is chirping?
The only other thing I can think that would chirp with the key off is an electronic fan.Some models use a cooling fan in the under hood fuse panel and this fan can short out and chirp and run like this here.I suspect this is what will be found needing replaced as I have had to replace several of these before.Some of the new fans that are installed are updated part numbers to prevent this from occuring again.
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