Yep I have changed mine out to a simulated air horn. If you unscrew the driver's side headlight and slide it out some, it will give you more room to work.

With both of them not working, I would check a fuse or maybe the switch in the steering wheel

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2001 X5 3.0i (PP/WP/AP) Traded at 213K miles
RARE White on Black - Why does everyone get Tan??
First E53 with 215s on XOutpost!!