2000 S70 Only One Horn Works

Warren561 · Post by **Warren561** » 20 Apr 2014, 18:28

Does the S70/850 have individual relays for each of the two horns in front of the radiator?

Symptom: Only the driver's side horn works when I press the buttons on the steering wheel. The passenger side horn does not make a sound.

Troubleshooting: I swapped horns to see if the horn itself is bad. However, it appears that both horns work. It seems that the passenger side connector is not getting any power when the horn button is pressed.

Ideas? I've read that there's apparently no horn relay? Are the horns just wired directly (ie high current runs through the steering wheel switch through the wiring and directly to the horns)? If so, I'll guess that the wiring has fried.

Or are there two switches in the steering wheel, one for each horn?

Thanks.

Post by **Ozark Lee** » 20 Apr 2014, 19:15

All the same switch and there are no relays. If the horns test good individually then the problem must be in the wiring harness or, more likely, one of the connectors.

...Lee

Warren561 · Post by **Warren561** » 20 Apr 2014, 20:07

Ozark Lee wrote:All the same switch and there are no relays. If the horns test good individually then the problem must be in the wiring harness or, more likely, one of the connectors.

...Lee

Lee, you were right on. I pulled out the cabling. It looks like vibration had rubbed off the wire loom protecting the wires and one of the wire's insulation. Corrosion did the rest.

I re-spliced it and all is well. I will be adding a relay next weekend when I've more time.