Mazda MX-5 Miata banner

Nb 2.5 Headlight Conversion Wiring

6.8K views 8 replies 5 participants last post by  Shane Burke  
#1 ·
Hi, I have a mk2 and I've put on headlights and from bumper from a mk2.5 but when I put on my full beams the low beams cut out as they normally would with a H4 bulb. This isn't much of a problem with halogen bulbs but I would like to use HID bulbs for low beams. With HIDs taking a some time time to switch on I would be left with darkness for a few seconds when going from full beam to low beam. What do I need to change to have the same wiring circuit as the mk2.5?

9bf806fbd5d427fa2309d88a1b084424.jpg


Sent from my D6503 using Tapatalk
 
#2 ·
Mk2 have only 1 earth (ground) to bulb but you need to split it in to two earths for mk2.5 bulbs.Then say, dip live and 1 earth to dip bulb and head live and earth to other bulb.
 
#3 ·
That is how it's set up at the moment. I have split the earth and both the full beam and low beam work individually. The issue I have is that the low beams on a mk2.5 are always on when the headlights are on whereas on a mk2 they switch off when the full beams are on. I want too keep the low beams on so I can run HIDs in them.

Sent from my iPad using Tapatalk
 
#4 · (Edited by Moderator)
the mk2.5 loom uses earths through the switches and the live are permanently to the bulbs (opposite of mk1 or mk2)I had similar issues when I fiited mk2.5 loom to my mk1. You will need relays on the earths ,as I did , to split/seperate the earths.Its not just case of dividing the earth wire itself.I had to fit 2relays , 1 for each side, as current was backfeeding to opposite lamp.You need auto electricain to do it properly

Also dont forget HID,s will fail NCT if not fitted from new to car.
 
#5 ·
I actually remember you telling me about that when I was getting an engine and box from ya. Ok I may stick on the thinking cap and come up with a wiring diagram. Cheers

Sent from my D6503 using Tapatalk