Ok guys, when my 175 arrived last Tuesday none of the lights worked. I knew that when I purchased the bike. Previous owner put a new battery in it. I have replaced the handlebar switch, ignition switch, all light bulbs and a new headlight. Ran a test on the lights today after I installed the new key switch and all the lights that operate off the battery worked, somewhat. I also installed a new horn, but not OEM. When I press the horn button it will click but not sound. When the turn flashers are on and I press the brake pedal the flashers stop flashing. I’m thinking I have a ground problem but I’m not sure where to start. The only place I can find that the wiring harness is grounded the frame is at the ignition coil. Is there somewhere else I should be looking for ground? Also, the front hand brake switch is bad, I have a new one, just haven’t installed it yet. I have not started the bike to test the headlight, meter lights and high beam indicator light. Anyone with experience with this please help. Neutral light works, but dims a little when the horn button is pushed.
Thanks in advance for the help.

Sounds like you don't have the bike running for these test? If not I'd fire it up and try again.

Ok, I think I have the horn problem solved. The horn tested fine on bench test but wouldn’t buzz when mounted on the bike. I adjusted the tone screw and now it buzzes while mounted. Beats me...

Sounds like it might be a combination of high resistance in wires/switches/connectors from corrosion and/or a weak battery.

Sounds like the same things my 74 DT100 and 76 DT175 do when the battery is weak. These batteries suck in my opinion. Start the bike and see what happens.