Trent015

I'm trying to restore a 65 mustang and I'm about to buy new headlights with halos but I was looking at it today and there's the plug to the headlight then this other little round in wire. I have no clue what it is and I was gonna try to find my parking lights but there's no wires. Is this the one to the parking lights?

houtex

You will have the normal 3 prong connector for the main light itself, but the extra wire that comes off it is for a 'key on' power wire to turn on the halos. You *could* wire it up to the parking lamps, but that'll require you to turn those on to turn on the halos too. And the ground for that. The halos are a separate wiring from the actual headlamp.

But for normal wiring for that application, you'll want a relay that'll turn on and off from a key on source, and the power supplied by a fused wire from the battery. At least that's how I'd run them. 'Tis but one way, but that'd be my way, 'cause that's the point... have them on all the time the car's running. So key on relayed power.

Anyway, here's a video to help ya.

Trent015

So that wire just means the halos can be on when I turn the key? And the main light doesn't have to be on? Also don't have to run the halos with the parking lights like one video said

houtex

That's correct. They use the parking lights version of wiring, though, because the LEDs are low amp/watts, so they don't affect the parking lights circuit, and it's a little easier. There's no real extra wires to run, no relays to hook up, no extra fuses, etc.

My preferred way for this requires you to have a key on source to then tell a relay to switch on fused power directly from the battery to the halos (and whatever else I want for key on, always on, stuff, like an amp for the radio or something.) This would require finding a key on source, running that to one side of the relay, then ground the other side of that relay's switching signal. Then run a fused wire from the battery to the relay's 'IN' side, then running the wire(s) from the relays 'OUT' side to the halos. Or whatever else I'd run on that circuit I'm making. Even to another relay to run an amp, if that's what I chose to do. And that then needs to have the wires, relay, fuse holder, screws and wire connectors to be acquired and dealt with.

But it'd be worth it, to me. I would be annoyed, personally, to have to turn the parking lights on for the halos. I just want them on if the car is on, so I'd do the extra work.

Neither the main light nor the parking lights have to be on. They can be, it's your call on that, really. Just have to figure out how you want to wire it and run it, and do the work.

ER12883

An option is to get a fog light switch so they are switchable if you might ever want them off.