Modern Vespa

I've drawn a crummy picture.
This is what dawned on me - I've painted and made my cowls all fancy. But the pin and wire seem to be feeding the electricity to the signal at the back (pictured as the red circle on the right and the red wire running to the back where the signal is.

So, where is the negative? It looks to me like the negative end of the circuit goes through the spring loaded clip which holds the cowl to the body. Is this correct?

If so, There are two points on the cowl which can't be painted - where the bolts hold the signal to the cowl (sketched as a dark blue line on the left near where the wire ends) and then the current flows through the cowl itself to the tab back at the front (dark blue square) which the spring loaded clip grabs to. These would need to have bare metal so the negative from the signal can get a connection to the metal of the cowl and so that the spring-clip can make a connection to the metal of the cowl.

Am I getting this correctly? Should I expose some metal where the signal nuts and bolts attach to the cowl and on the tab on the front of the cowl where the clip attaches?

On my P200 the positive comes through the pin, goes through the bulb, then grounds through the signal fixture to the cowl, then back to the frame with the cowl latch. So yes, a good ground at the fixture with the mounting screw/nut, then again at the cowl latch should do the trick.

not advocating this, but i've actually seen people make redundant ground wires from the lamp to the frame, so it doesn't rely on the mechanical grounding.

You'd want to hook up a quick-release harness wire or something ( maybe bullet connectors ) to make this work. It would have to be something you' disconnect every time you pulled off the cowl, so ease of access is key.

But why? Does the stock setup not work well? Seems a little funky but doesn't look like a completely ineffective design

It works fine stock, but if you've got a thick paint job on there and the cowl is not grounding to the frame anymore, it's a way around scraping off paint.

Ah. Too late What i did was carefully scrape a ring down to the metal where the nut from the light fixture carrying the ground attaches to the cowl, and I scraped the paint off the copper contact on the tab where the spring-latch attaches. That should do the trick, right? I guess I'll find out...