92 pickup. Currently have the stock sealed beams I orders a pair of led headlamps to put into it and I plug them in and they don't work. I looked up a wiring diagram and it seems as my truck uses grounds to change high and low not a power to change high and low. And I know a halogen can be wired either way and a led can only be wired one way to work. So I have constant power but my grounds switch for the lights. Is there an adapter out there for this to work. Otherwise it will take alot of wiring and relays and fuses and what not to make it work... is there somthing simple out there. Thanks for your time. Please help me out here.

 

There must be a simple fix, but please do your homework first and let us know what LED light you are dealing with, wiring diagram to your LED light.

BUT if it is one of those non-DOT approved LED headlights that light up the sky and blind others, PLEASE PLEASE PLEASE BE CONSIDERATE AND RETURN IT.

 

But we will ignore the safety issues and tell you. Any random relay harness you find on eBay or another online supplier will either work plug and play or only require swapping some wires around.

Don't forget you'll need to do some alterations no matter what you source if it's not a Toyota specific harness that includes the work around to activate the high beam indicator when appropriate.

 

Legit, great spread, sharp cut-off, safe, considerate and 100% plug-and-play... trucklites.

 

Wiring, relays and fuses? I'd like to see that wiring diagram.

All you need to do is pop the pins out of the headlight socket and reverse them. Of course, you'd want to use jumper clips first to confirm that polarity is your problem.

And please do check that the lights are DOT approved. Otherwise, even swapping pins in a connector isn't worth your time.

 

Can you walk us through that repin? Or is it beer thirty already...

It's three pins one power two grounds, you can not swap that and have selectable lights.

Not at the plug side at least, you could rewire the lamps if it's not a sealed unit.

Switched ground to switched power harnesses are on eBay.. probably from the same guys selling the led headlight lamps.

 

Yikes! You're right. The LED headlamps are (almost certainly) wired internally with one "minus side" (cathode) and two "plus sides" (anode) (for the high/low beam).

Fixing that will not be nearly as simple as I thought. Sorry.

 

aaaah. clash of the big brains!!! looks like Co won this round. Can scope pick up the win in the next match? STAY TUNED TO FIND OUT!!!

 

Correct.
Yes, on each trucklites legit LED sealed beam there is one positive side common to both low and high beam filament that connects to the headlight fuse. The headlight control circuit selects high beam or low beam by grounding the separate ground sides for low and high beam filaments. IF O.P.'s circuit is stock but LED lights do not work with it, the LED lights must not be the right ones for the truck, and yes, it would require a harness that converts switched ground to switched power.

 

A good quality set like the Truck-Lites or Speaker sets are the only way to go. More money but they are the best bet for reliability and output

if you have a set that sells on ebay for about $65 those are not DOT approved.

 

This is the diagram for my truck.
sorry for not getting back quickly. But yeah there is the diagram for my truck does that help anyone in any way? Seems like everyone is understandING my situation. Am I right? If so has anyone actually found an adapter?

 

Other half of the diagram.

 

We also need the info, especially polarity specs, for your LED lights. Chances are its pin-outs are:
One POSITIVE input for low beam
One POSITVE input for the high beam
One COMMON negative/ground for both beams.

If this is the case, find an H4 conversion harness that has separate positive outputs for the high and low beam filaments and ONE common ground pin. I believe the common H4 conversion harnesses being sold online works this way. Other members who had bought some would know.

Regardless of the above, I still implore you, IF your LED Lights are not DOT-approved, to not join the band of A$$holes who light up the sky and blind others with their non-DOT-approved headlights.

 

If trick30s LED headlights "don't work," you are almost certainly correct. But there's only one person who would know for sure; the one holding the documentation that came with the lights.

After my gaff, I took a look to see if I could find such a harness. There are lots of H4 harnesses, but they either just add relays to keep the headlight current out of the stalk switch (advertised as eliminating dimming), or they are for later-model vehicles that misinterpret the low-current of the new LED headlamps as a burned-out bulb, and give a false warning.

Neither of those types of harnesses will do the polarity reversal as (correctly) described by RAD4Runner.

From an electrical standpoint, I can't see any reasonable way to do that without two relays, exactly what trick30 said he didn't want. If it were me, I have no trouble wiring up a pair of relays, but I wouldn't bother. I'd return the headlamps and get the right ones.

 

I had no luck looking for switched ground led assemblies. It stems from the design of the LED (cree which most use or clone) where the cathode is used as the heatsink.

Anyways go here read lots buy his stuff or diy and send him a thank you note..
http://www.4crawler.com/4x4/CheapTri...shtml#TechInfo

 

Seems Truck-Lite claims that their LED head lamps are NOT polarity sensitive. https://www.truck-lite.com/content/f...rity-sensitive Go figure.

 

LOL!. Exactly.

Almost certain that P.O. needs a switched-power conversion harness as 4 crawler describes here.

 

Hey RAD, didn't I see something about you run a set of TL lamps?

 

Yes, I do (here) and am very happy with them.
Plug and play, so not worth a write-up.
Great spread
Sharp cut-off,
Less power consumption, of course.

Only con is that there is a hot spot on each bulb's pattern (Haven't taken a picture of it nor written TL about it, yet). The hot spots point a little higher than the over-all cur-off, so I'm putting those to good use by aiming them at the lane reflectors so I see those ahead of time.

Other potential con is because of cooler lenses, snow may accumulate on them. Not a problem where I am .

 

i finally upgraded mine to led. I did buy a harness off eBay and was really easy and now I should be able to use whatever headlights I want. Did a video review and install. I should have read here first to know that they would not be plug and play 🤦˟♂️. $18 for harness seemed easier the building one and has been working great!

https://youtu.be/yrjbcTU_GTc