1990 Eagle Talon Horn Problem

Greetings,

I have a 1990 Eagle Talon Tsi that has the factory theft alarm. When
the engine isn't running, the horn works fine. But when the engine is
running, the horn is intermittent, i.e., it mostly doesn't work.

I checked the horn relay, and it seems fine. The horn switch goes to
the theft alarm module. There is a wire from the theft module that
activates the relay. Since both the horn and the theft alarm can
activate the horn, I wonder is there's isn't some diode "or" gate in
the theft unit with a bad diode.

I don't really need the theft alarm, so I'm thinking about doing a
little cable splicing and hooking the horn switch directly to the
relay. The other option is to visit the junk yard and try another
theft alarm.

Any suggestions?

Regards,
Benjy