simple trouble-shoot and fix. if you don't have one buy yourself one as per pic. a few bucks buys quality and a lifetime of assistance. on your ulysses simply remove the windscreen to access the horn and wiring in the headlight bucket area.
the bucket bracket is a large ground source as is any black wire observed in that area.....black wire in 4-wire headlight wiring harness also ground source. then do this:
1-go to headlight wiring harness and disconnect. you'll be probing the ORANGE wire in the harness on the main harness side.....NOT the headlight assembly side. with key on and test light grounded probe the orange wire on the harness plug end....NOT the headlight assembly harness plug end. test light should light. if not it is not grounded properly. after establishing that test light is now working plug the harness back together and move on to next step.
2-turn key on....red-run switch to on just to be sure....make sure the wiring plug is connected to horn....press horn button....and probe horn terminal with test light. test light does NOT illuminate? try the other horn terminal. test light NOW illuminuates? bad ground for horn circuit.
3-do precisely the same procedure for your uly dash mounted power outlet. CAUTION HOWEVER: when doing the test you will be probing the center connector terminal inside of the outlet. that is the positive source of the outlet. do NOT touch the sides of the outlet with the test light probe while performing this test or you'll pop the circuit fuse.
4-you'll find that it was not coincidental that both your horn and power outlet ceased operating at the same time. they both source their ground from the steering neck area ground loom. your problem lies there.
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