no OIL pressure Light & no horn related??

Been frustrated all day. The 73 z1 I have no oil pressure idiot light with ignition on , bike non running. Bulb is tested good. Remove bulb stick in test light turn on key Light's up. Start bike test light stays on. Replace good bulb, nothing.
Horn nothing. Try several horns nothing, they all can't be broke. Not even a click
Are both these problems related ? I checked ground wire to engine . I know the battery is older with new acid seems to hold a charge. Has enough power to run turn indicators and start bike. I just haven't gotten around to get new battery yet.
I'm taking a little break, been wrenchin on the z1 last two days.

Any input appreciated
gregz

Test to see if there is voltage to the brown wire going to the dash cluster, there is a splice in the brown wire in the main harness that goes to the horn and the oil light.

A weak wire there may not be letting full voltage in. Didnt say i it's original harness or not? Kawasaki has shit splices in these harnesses tons of gang-green at the splice points

Also check to see that there is power going to horn, the ground for the horn comes from your handswitch and that seems to come from where the switch housing clamps to the bars.

horn problem has been sorted. I have at least twenty of them just started plugging another in, finally found one that honked.
I may never find the oil light problem that could be a bad wire in the loom. Tomorrow I am pulling the little cover off the bottom gauge cluster poke around a little. It's always something

Check the voltage to the oil light and to the brown wire to the dash cluster. Your oil pressure sending unit sends the ground to the light.

But if you are using the original wiring probably a bad joint in the harness for the dash
The working horn should mean the wire TO the dash is good