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LED Headlight Wiring for Common Positive Loom
Barkalarr - 28/10/20 at 08:02 PM

I'm using the standard Miata / MX-5 wiring and I'm trying to fit Halo led daymaker headlights.

Off the bat, it doesn't work. Upon digging a little deeper, I've found the MX-5 wiring diagram shows the headlights as a common positive and switched earth for the low beam and a switched earth for the high beam.

Question : how can I convert the switched earth into something the daymaker is going to work with?

I do have an idea using 2 relays, but that's a bit Heath Robinson and i don't really want to do that.
Anyone else got a better idea?

Miata Wiring Diagram

Halo DRL Wiring Diagram

[Edited on 28/10/20 by Barkalarr]


SteveWalker - 28/10/20 at 10:17 PM

Something doesn't match up there. The Halo diagram shows the centre pin on the H4 connector being the common, but the relay diagram shows one of the side pins being common. The latter appears to be correct.


Mr Whippy - 28/10/20 at 10:22 PM

Personally I'd be perfectly happy using two relays as headlights are usually operated using them and many use two relays... they are usually extremely reliable so long as the current is within their rating and good thing about using two is if one fails you still have lights


gremlin1234 - 29/10/20 at 11:42 AM

quote:
Originally posted by SteveWalker
Something doesn't match up there. The Halo diagram shows the centre pin on the H4 connector being the common, but the relay diagram shows one of the side pins being common. The latter appears to be correct.

I agree, the pic with relays is h4
the other pic seems to be for the old sealed beam standard h4656, not h4