Thanks for the update! So...
Those headlights require switched positive circuit (relays select where to send 12V, to low or high beam bulb), correct?
The common pin on your H4 connector is now connected to ground?
The harness converts Toyota's switched-ground to switched-positive circuit?

 

The harness plugs into the passengers side factory headlight H4 female end and then runs to a relay, essentially making the factory wiring the switching wires (don't know proper term). The relay and lights get their power from being directly connected to the batteries positive terminal.
Essentially the relays don't care which way the power for the switch runs through it, so toyotas switched ground works to trigger the relays, the power from the batteries then feeding the H4 connections of the new harness are now the proper polarity to run these lights (and any other that would fit) properly.

 

It was a lot easier, and probably similar cost, to how others were doing it on you tube. But they were putting two relays per headlight so four total. Not needed. So far these have worked great and I don't have any problems with the stereo or getting a buzzing sound (the advantage of switched ground is less likely to get interference with other systems) so I must have done something right and has been working fantastic. I will never go back to the stock headlights. Links for the relay
https://m.ebay.com/itm/2-Headlight-H...t/262483542712

 

Now for some night time output shots.

 

Correct, maximum needed are 2 relays for both headlights. Also possible to use only one, IF keeping switched-ground.

 

this!

 

Ok so by popular demand. Here are some night shots I just took. Keep in mind I still need to adjust which is appearent in the high beams more then the low.
So this is down the street. There are NO street lights. Only the lights from the truck. The low beams are diffused and cast a big area and do not have a crisp cut off. Just a lot of light.
Here are high beams. The highs are not diffused and more direct. I need to adjust passenger side so it's not pointing down and the drivers so it's not crossing. But you can see the mail box and tree are more illuminated then low.
Here is across my street and a distance of around 30 feet. Again nice wide spread on low.
High beams at this distance are really bright. Just not adjusted 😂

 

I bet if you pulled behind someone you could blind them from their rear view mirror. They seem to cast a lot of light above and beyond where light is needed and that would blind on coming traffic as well. It is recommended that the cutoff be around the same height or lower than the height from the ground to the center of the headlight. Any light above that is pretty much in every other drivers eyes. Maybe take some pics next to a car and see how the light pattern is then.

 

yes. I don't want to be the person blinding others. Will adjust my lights this weekend so that the highs point straight and compare to our other vehicle, an F250, side by side at night to compare how much light down the street and if I can pull up to the garage door, short distance cut off between the two. Obviously the F250 is taller, but a gauge of light above headlights.
Will keep you posted.

 

Yeah... Cut-off does not seem sharp on those lights, but we'll see after Blue Toy takes a closer look.

 

out of curiousity, why wire these using relays and drawing power straight from the battery?

that would make sense if they are drawing a lot of current, but they aren't, per headlight on bright they are drawing a max of about 3 amps.

wouldn't it be possible to accomplish the same thing using a diode bridge instead of relays?

 

Yes, Quite possible for those who are electrically savvy, but to the average truck owner it would be simple to buy off-the-shelf kits like O.P. did.

 

lol... all LED's are polarity specific. I had to modify my switch connector to run a positive though the switch by tapping into a ignition hot source and cutting and eliminating the ground word completely. Also ran negatives straight to the lights so my switch works perfect now for both high and low beams. BTW I did attempt to reverse the polarity before the connectors to to lights themselves via relays simply to avoid the headache, unfortunately my cheap ass only had cheap relays so they worked but were super dim. In the end I gave in and just created my own circuit to accommodate my needs... the joys of living the TOYota lifestyle. I'll have to take and post pics later.

 

LEDs themselves are polarized, but that doesn't mean the FIXTURE has to be. All Truck-lite would have to do is put a bridge rectifier before the LEDs and their fixture would work "either way."

I don't have a Truck-lite, so I can't say that is what they do. My guess is that if they advertise that you can use a switched ground OR switched hot, then you can.

 

Curious... Do you have Truck-Lites? What model / part number? It is quite possible that other manufacturers do not take the extra step to make their bulbs reversible.

Pin-outs for 27450C's from Trucklite Tech Support itself calls white wire "ground", green wire for low-beam and red wire for high-beam. Therefore it should work with switched-positive control that many H4 conversion harness use as below:On the other hand, Truck-lite 27450C's plugged-and-played into my switched-ground circuit. Meaning white wire that TL calls "ground" is really "common". Green wire is connected to ground for low-beam, Red wire to ground for high beam:The above confirms that Truck-lites are NOT polarity-sensitive (theoretically because I have not seen it for myself, yet).

 

I've been playing with leds for quite some time now and from my experience they ONLY work when connected +/+ -/- polarity does matter I'm not sure what brand my headlights are but they were two hundred bucks on eBay basically there is no name Chinese knock-off ships but they look cool nonetheless and work great. But as for the kits you're talking about that will just plug into an earlier Model Toyota pickup like mine which is pretty much mashup between a 79 81 82 the only way for it to be plug-and-play would have to be through a relay that will reverse the polarity I just use the relays I have sitting around from my donor trucks but none the less my lights we're still pretty dim which is the reason why I eliminated the ground wires wires feeding the switch in the harness and tapped into a power making my headlight circuit positive rather than negative and then just grounded this headlight connector to the chassis with zero issues thus far

 

If you're having difficulty understanding how a bridge rectifier can easily convert any LED Headlamp into "non-polarized," this may help. A bridge rectifier big enough to handle this load (about 1 amp) would be about the size of your thumbnail and cost $.50 (you'd need two for each headlamp). LEDs really need a constant current supply (even cheap Christmas lights have a few ICs to do that), so a headlamp manufacturer COULD easily incorporate the bridge rectifier into that circuit. But I'm sure eBay would serve up plenty of Headlamps without the constant current source or the "non-polarizing" circuit. As I said, I don't KNOW that Truck-Lite does it this way, but it certainly could.

I should mention that any truck owner could convert their own cheap headlamps with this solid-state solution. No relays, fuses, or what not.

 

Yes^^^, just a matter of finding the correct current rating for diodes.
If I were the manufacturer who wants its product to be plug and play for either switched-positive or switched-ground control system I would use the bridge rectifier approach. Truck-lites most probably uses it.