Elias2009

Hi, about a month and a half ago my passenger headlights' high beam when out but the low beam was still fine. A few days ago the drivers side high beam went out also but low beam was again still fine. I decided to change the bulbs but the bulbs were like $60 so i ordered an LED conversion harness for a bit cheaper. Plugged them in and the low and high beam worked so it was all good. Few hours later i come to drive my car and test out the lights and the passenger light high beam isnt working again! I swapped the high beam fuse with another fuse i know works but nothing happened. Any ideas what i could do?

08'MustangDude

Clean the harnesses? Seems like an intermittent issue. There is one relay for
the hi-beams, so it's not that or both would be out at the same time. I usually
take a dental tool, and push the contacts closer together at the factory harness
so the pins make better contact.

Elias2009

Would using electrical cleaning spray and a paper towel do the trick?

08'MustangDude

You need a tooth-brush to clean thoroughly. The bristles will need to get into
the holes a little, with contact cleaner too, and clean it good. Then slighly
push the sides of the contacts in towards the center, of each one. So, when
you plug it into the bulb, it makes better contact. That tightens up connection.
I do it all the time when I change bulbs. Use dielectric grease to prevent future
corrosion.

If cleaning doesn't work, then you have to trace a wiring issue, chaffing, or
broken wire inside the insulation.