12xb battery drains and has been replaced more than once always on tender, Harley thought ground wire on painted frame cleaned it same issue one week later

as above most use frame for ground. if you find not works you could try taking a tickler wire and ground the lights to frame

It's a battery or ground problem. You mean all of them, headlights, dash lights, or what? The flickering is often caused by a corroded or deteriorated ground point for the lights, less common is a hot wire connection that is loose or not contacted well. Your headlights and front park lamps and any side marker lamps, I think they would all have a common ground, or maybe each side has it's own ground up front there. I'll try to find a wiring diagram for what you need, in the meantime, take off first the negative of the battery and then the positive post (for safety, always remove the negative first and reconnect negative last), clean both battery posts and the end of cables or the clamps that go on the posts. Any corrosion, green or white colored, is not good, and can lead to serious resistance in the connection, and hinder the electrical system. Those connections must be clean and tight, remember positive hooked up first, then deal with the negative post. Your truck is old, subject to rust, better check all your ground connections. The original negative cable had a large ground to the engine block and a smaller wire ground to the body, somewhere grounded in front of the battery to the frame. If rust is an issue, you can always find a better ground point-to clean metal free of paint.

If you know all this and you know the battery connections are clean and tight, then look for the ground point for the flickering lights in question. If you have a voltmeter it is almost essential to the testing or checking of any electrical circuit.

Seems like you're definitely right. Get wiring schematic for your bike sounds like you're grounded out somewhere. Get yourself a battery tender or you may need a new battery cuts the voltage on the battery should be about 12.671 V not running

Battery tenders eventually kill batteries, regardless of type. When your bike is idle for a week or longer, disconnect the negative terminal of the battery. Use your tender for maybe a week before putting unit back in service.

Check for a loose ground wire(s). If you cant find a loose ground wire check the ground post on the battery. sometimes the ground post will break off inside the battery(especialy w/ the cheap junk they have for batteries now)Sometimes you can solve a ground or negative issue by running a secondary ground from the battery to say the firewall or frame. Make sure you clean off any paint and undercoating down to the bare metal at the point you are attaching the new ground to.once the ground is established put some light paint on the spot to keep out rust.

You can attach the negative lead of the battery tender to any bolt on the frame, that will give it a good ground and work fine.

Check the battery connections. Remove, clean and reinstall them. You probably had them off doing the wiring and they aren't making a good connection now. Always remove the negative first and install it last.

You've got something that's pulling from the battery. It could be as simple as a loose connection or bare wire touching the frame, it could also be a bad relay, and this will generally show when testing for an open circuit. Check any added electrical devices. Also, keep in mind that the system on a Harley doesn't charge the battery, it only keeps it topped at where it's at. So, if you have a half charge on the battery, you can ride to Hawaii and back, and you'll still only have a half charged battery. This is where a battery tender comes in helpful for garage time. I'm afraid you're just going to have to start tracing wires, and checking relays.