I converted to this 4 years ago I think and have never had any issues. The new problem that I'm now having when I have low beams on, only the low beam 9007 low(bulbs) on both driver and pass side work. The other bulbs 9004 are not working.

when I switch it to high beams its reversed. the bulbs that were not working in low beam (9004) come on as high beams. and the other bulbs that were on only for low beam (9007)are off. hope I explained that clear. it was getting dark so I was only able to pull and look at all 15 amp fuses on the engine bay they are good.
the sport conversion harness has fuses on both side pig tales those appear to be good too. now the relays that are on both sides of conversion harnesses have 2 per side. I pulled them and looked at them they look good. the relays are just there to pull the power from batteries.

what I'm I missing? is this a switch issue in the cab?

I dont have the bright box set up. I cannot remember what kit or harness I bought years ago. originally both sides 9004 low and 9007 lows came on when I had low beams in operation. and both 9004 and 9007 High came on when hi beams were activated.

 

That is how I have mine wired. Lows in parallel and highs in parallel. No lows with the brights (yet). I did the simplest wiring through relays. If this is how yours are wired, first check the bulbs. If they are okay, check the wiring between the two sockets. If you have some other box, switch, or diode in there, check it.

 

Just for grins, are you sure the bulbs haven't failed?
I've seen both sides fail within an hour

 

it would be weird if the 9007 both lost High beam, and both 9004 lost low beam.

 

Have you swapped relays?
I'm not familiar with the store bought harness. When I has Sports, I built my own.

 

I did try and swap. Didnt do anything. Im buying new ones. But will be a few days. They are 5 prong relays. My part store napa wanted 20$ a relay. No thanks. I found them 3$ a piece on line.

 

Before you toss cash, pull the relays and put a meter across terminals 85 and 86.
this is what turns them on.

 

If you're not seeing power at the coil terminals, I'd check back to the headlight switch and connector itself. I've seen some 2nd gens fail more then once at the connector.

 

I would think the problem must be within the conversion harness. The high beams should have a parallel connection within that harness. The low beams should only light the outer bulbs, if the conversion harness is wired to work like the factory setup. The headlight switch shouldn't come into play here with this issue.

Additionally, make sure nobody has confused the headlamp plugs and plugged one that is meant for a 9004 into the 9007 bulb, or vice versa. The plugs will physically fit into the wrong bulb, but the pinout is different and won't work properly.

 

i found my old thread from long ago. I bought a harness through suvlights 4 years ago. its been trouble free till recent.
with this set up on low beam all 4 bulbs were on low.
with this set up on high beam all 4 bulbs were on high.

now
on low only the outside 9007 bulbs are on.
on high only the inner 9004 are on high.

people say this was the way its suppose to be. but this was not the way the harness was made.

I have 2 relays per side. (2) being tradition 5 prong relays. the other stuff a fuse on each side. ground wires on both sides. the big socket where it connects to the oem socket and then there is a black push on box that has about 6 wires that is part of harness pig tailed off haness just a inch and its a box that if you push in a tab you can pull the female part of box off the male end. ?? the name on this is key lux. (part manufacturer). I dont know what that part is.

 

Little rougher working with a conversion harness that had a 4 light always on gimmick as a selling point. As it is now, it's working as the sport headlamp was intended to work.
curious
How did you ever aim them correctly when it was running all 4?

 

This is how mine is wired except my left and right sides are separate harnesses. The relays are switched from the old light connector on that side. Each side has 2 relays, 1 for both lows and 1 for both highs, and 1 fuze per relay. The light sockets are hooked in parallel. About as simple as you can get. Your problem is in the box.

 

Okay, found as diagram of what I have X2, one for each side.
http://www.taurusclub.com/forum/117-...ness-gen4.html

 

so when you say my problem is in the box? what box? are you talking about the square black box that says key lux?

 

That would be my vote.