Electrical experts help with headlight harness

[Bigmd]

Ok, purchased a nice hd headlight harness off eBay. It’s not a cheapo one. Has 3 good relays and fuses on it with thick wire. Anyway it was pretty easy to hook up or so i thought. I have a 2002 and i cut the DRL wire so i can use the harness. When all was said and done , my headlights would not go on. I checked all the connections. There is not much to screw up. The only problem i could see was when I hooked the power wire to positive I connected directly to the painted red battery clamp. I’m thinking it wasn’t a good connection. I was running low on daylight so i disconnected and modified the ring terminal so i can connect to the accessory point on the terminal. After i tightened, i checked for voltage with multimeter. I was getting power to all 3 relays. When i checked the male trigger plug it wasn’t reading any voltage. Shouldn’t i be getting a reading there? I ran out of time and light so didn’t get to hook plugs back up to headlights. Any help is appreciated.

 

[infantry503]

I had a relay issue when I did my retrofit. It turned out to be an improper ground. Once I fixed it they worked fine. I don't know what your DRL plug looked like since they seem to be different but mine just unplugged and had zero issue with lights not working. Maybe cutting those wires did something to the electrical part of it. Maybe try unplugging the DRL plug and see if that works.

 

[Bigmd]

Thanks. On the 2001-2002 there is no DRL plug under hood. The easiest way is to cut a wire under dash which is what i did. I double checked and it’s the correct wire. I’m hoping it was just a bad connection.

 

[Bigmd]

Still can’t figure this out. My headlight low beam fuse was blown so i figured that’s what the problem was. No such luck. Headlights don’t work . I’m getting power two two relays but the 3rd which is the ground i get no reading. I’m assuming because it’s a ground. Can someone confirm this? Also this harness says won’t work with factory DRLs. I disabled them assuming it would be ok to use it. Am i incorrect with that?

 

[phattyduck]

Do the headlights work as expected when plugged into the stock harness?

Do you have a link or diagram for the upgraded harness you are using? I'm curious what the third relay is used for...

-Charlie

 

[Bigmd]

Yes headlights are hooked back into factory harness and work fine. I traced the black ground wire back to the 3rd relay. Also shouldn’t i have a voltage reading to the trigger plug when everything is hooked up? Interesting thing is the instructions show a harness with only 2 relays.

 

[Bigmd]

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/192188107487
Here is eBay link.

 

[octanejunkie]

I assume the first relay acts as a trigger for the second two, one per headlamp. I also noticed the eBay listing says NOT for DRL or Factory Fog vehicles.

So I have to ask, why did you buy this, what problem is it solving?

 

[Bigmd]

From everything i read online as long as i disabled them i would be ok. That’s what i did .

 

[weezykid]

Madrvr is on this site as well: Madrvr Member Page

May want to hit him up directly for suggestions. I have this harness and it worked without issues on my 96 with no DRL's.. Wish I had some more helpful info.

 

[Bigmd]

I emailed him through the company . Waiting to hear. I’m beginning to wonder if it’s not gonna work even if i disable the DRL.

 

[weezykid]

I imagine there is a routing different between DRL's and regular. Fogs must be routed similar to the DRL's as well. The DRL power would ignite at the start of the car where the low beam would be activated by the headlight switch in turn, deactivating the DRL. If it is this simple the DRL/fog harness would have more wiring to the plugs and a different routing. Im wondering with the DRL disabled by the wire cut, it is giving you the DRL power to the Relays, but at the activation of the headlight switch, it is cutting that power.

I have AllData Pro access and will see if I can log in tonight to look at the schematics.

 

[Bigmd]

Thanks appreciate it. FYI i don’t have factory fogs.

 

[phattyduck]

We will need to know what wire you cut.

The 2002 DRL system is really integrated into the headlight system. The issue may be that the DRL vs. non-DRL headlight circuit use opposite headlight connections (common power vs. common ground) that might mess with the way the headlight harness is made.

-Charlie

 

[Bigmd]

On the 2001-02 it’s pin 12 on the under dash harness.

 

[Bigmd]

I got a response. He said the harness is for ground switched 4runners. It can not be used with power switched vehicles. Im guessing I’m power switched?

 

[weezykid]

Sorry for the delay. DRL harness is much more complicated than the non-drl (more so than I thought).. So I can see why they specify not for use with DRL's...

First image is the non DRL harness, Second pic is the DRL harness.

 

[19963.4lsr5]

It does make you wonder why Toyota went through all the work of providing a power relay for the headlights and still run the grounds through the switch. Not to mention those dinky 18 or 20 gauge feeding the headlight sockets.


Sent from my iPhone using Tapatalk

 

[4Runner4Leon]

I got a response. He said the harness is for ground switched 4runners. It can not be used with power switched vehicles. Im guessing I’m power switched?

According to the diagrams in weezykid's post, they are indeed power switched.

 

[Bigmd]

Yeah guys thanks. I spoke to Mike from the company i bought from and he confirmed. He did however offer a refund if i want and he will send me correct harness.