Headlight volts drop

[Mustang]

If its a gen 1, these are notorious for

• having undersized cables in the sub-loom, sits under the front cowling, connects to the main loom.
  
• the same undersizing on the cables going from the reg-rec to the main loom.
  

My FZS had a similar issue in that the volts at the clocks was sitting around 10v with the headlight on, I go around this issue by running an extra ground to the clock from the small frame mount above the reg-rec. Then I changed the halogens for LED -

• https://www.amazon.co.uk/LED-Car-Headlig...i%2Flo+LED
  
• https://www.amazon.co.uk/Fastcar-headlig...i%2Flo+LED
  

I went for a fanless design because rain would just kill a little fan in now time, and where the shaft behind the bulb is the exact same width and length so the rubber headlight boots seal against them keeping the headlight sealed.

These LED bulbs have several benefits over HID but primarily you get proper hi beam and with a much better low beam pattern.

Thanks for your reply, I suppose it’s just easier to fit the leds