It's not the contacts that cause this to occure you can drive with bad contacts - Just No Horn - but it is the incorrect installation of the airbag.
To check with engine running turn wheel left till steering lock and then right till steering lock if the light flikers or lights up the the airbag is not installed properly.
Airbag Installation:
1. Plug in gas generater till lead is seated home. It should click!
2. Place airbag on steering wheel.
3. Turn left side socket head to spec of 6 nm.
4. Turn right side socket head two full turns.
5. Slightly raise right side of airbag from steering wheel and tighten to spec of 6 nm.
Recheck steering lock procedure.
Hope This Helps!