Odometer cluster not working + constant horn output on 300m?

Just last night my 2001 300m started going bonkers - the horn is
constantly engaged and the odometer cluster isn’t functioning. I
pulled the fuse to the horn and while the car still starts, and all
other functions seem to work, the odometer still isn’t working and if
I put the horn fuse back in, it still is constantly engaged.

Anyone have any suggestions as to what to look for?

 

Have you checked the horn relay?

 

you need to have the faultr codes pulled form the computers in the car first thing

 

There may be a driver IC leaky or shorted on the output from the body
control module (horn relay output circuit). Also check for power
sources to the BCM, and J1850 bus communication problems.

 

if you have the fault codes pulled you can assume a lot less in whats causing the issue
have you had a windshild replaced lately???