My new project car has a weird horn problem.

I was looking everything over, making sure it's roadworthy/safe, and had no horn.

Both horns were unplugged, so I plugged them in.

Hit the horn button on the steering wheel, and the tone sounded a little off. So, at this point, I'm thinking one of the horns is bad, and that's why they are unplugged.

Then, I put the car into reverse, and the horns stick on!

As long as the car is in reverse, the horns honk!

Any ideas where I should start looking?

 

If I were you, I'd be looking at the wiring diagram.


I wonder if there was some sort of safety feature that allowed those to be cross connected. It's not natural, that's for sure. On a normal car (non Volvo ha ha) the horn circuit is extremely simple, but it does go through the steering column. However, nothing electrical in the steering column knows you're in reverse.

 

The 850s are prone to breaking the contact clips inside the wheel. you can buy a repair kit for the contacts for $35. You should be able to find directions online but basically there are some 30 torx screws on the back of the steering wheel that allows the press pad to pop off. You have to move the airbag to the side (so disco the battery!) - took me less than 30 minutes to fix mine - 3 of 4 contacts were cracked, 1 completely broke which made the horn stick on.

 

Excellent!

I have a spare tan 'R' steering wheel, so I may take some leather cleaner to this one to decide if I'm going to fix it, or just swap it out.

I searched for the repair kit, and found this one for $40. Not gonna rule it out, will unhook the battery and pull the airbag and have a look.

 

sounds like a plan. BTW, I meant there are size 30T torx screws in the back of the wheel, not 30 screws :-) you need to crank the wheel full left to remove a couple then full right to remove the others. The pad pulls off from there and the rest is pretty obvious from there. You'll see the small red tabs with wires in the wheel hub - look for cracks or broken bits... You can find picture directions via Google.

 

Sure enough, the contact is broken!

I will be cleaning up the wheel this weekend. If it cleans up OK, I'll spend the $40 on the repair kit.

If it doesn't, I'll put on my spare 850R tan steering wheel.

 

Just to add closure, I put the 'spare' wheel on for the time being, it's a little better than the one in the car. If I can find a way to save the leather on the original wheel, I'll spend the $40 to replace the contacts.