Towing harness issue SOLVED!

I do. Got the oil cooler and all.

 

Thanks. That confirms that Toyota really did use the 4 way flasher harness with the factory tow package and DTRL in ‘12.

 

Does that mean I can no longer bypass the DRL? I wasn't sure if the non-DRL relay and junction block caused the problem so I removed it. I really hate the DRL being so hot and turning the headlight lens yellow.

 

There is a way to disable the DTRL by cutting a wire. You’ll need to search here to find it.

 

Yea I saw that. And then I saw the one by replacing with base model relays. Guess I'll have to go snipping.

 

The question is what got the flasher relay hot like that.

Do you have a boat trailer? (i always unplug the trailer harness when backing my jetski trailer in the water)

Also no need to worry about DTRL melting things on the 2012+ trucks.

 

Yes I always unplug from truck when going into water. Been towing boat since 2005 with my first Xterra to 4runner.

Coincidence or not, this happened after I put in the non-DRL relay and junction boxes. I can't pinpoint that's the reason why the flasher relay got hot, but I've tow with the Tacoma before and it worked fine. I did the DRL bypass in May of this year and I tow the boat in June and smell the burning. I wasn't aware at the time if the lights malfunctioned or not.

 

Hmm weird. Keep an eye out on the new flasher relay when used with the non DRL relay.

 

OP, would you upload a pic of the bottom side of the burnt board?

 

As for now I went back to factory setting just to make sure I've 100% fixed the issue. I'll tinker with it again in a month or so with the non-DRL relays.

 

hard to put the blue smoke back into electronics. Yeah that will do it!

 

De-pin or cut then tape up...

 

I get this is two years old but I was wondering if you ever verified the lights are possible with the non-DTRL relay? I did the same mod but added a smart tap flasher relay so that I can tap my turn signals for 3 blink changes and it works properly with LED bulbs-no resistor required, and I have switchback turn signals that are white when dtrl circuit is on, like with the headlights. I would really like to keep these features and not cut the dtrl wire.

Factory towing package, trailer lights turn on but no turn signals or brake lights. Checked every fuse and it's all good. I do not have a brake controller wired up, pigtail is still in the glovebox and I was really hoping that's all that's needed to get this to work but not sure.

 

The OEM relay handles the towing combiner (it's integrated to turn relay), removing it and adding the "Smart Tap" relay has removed that towing feature. BTW, the towing tail has it's own relay and is a separate circuit from the combined towing Stop & Turn circuit.
Also, I don't think you ever had the DTRL feature, the OEM DTRL relay sends steady power to the Bright filament (incandescent bulb) and when turn is selected, it sends the intermittent power. Once Tails/Parking lights are selected then both filaments are juiced. When Low beams are selected, the DTRL (bright filament) turns OFF, inly to work when turn is selected. The DIM filament stays ON.

 

Yeah that makes sense because the tail light works as normal. Studying your post taught me that actually. I've been studying this post by you for the past two hours: https://www.tacomaworld.com/threads...ow-turn-with-drl-relay-on-a-2011-2005.643600/

It seems to me that if I were able to get a female connector for the Smart Tap, maybe by cutting one off a scrapyard BECU, I could modify my stock harness and get everything working. Plug 1L back in, send turn signal combo switch inputs to both the smart tap and the DTRL Relay, then de-pin T20 turn signal lamps and put them on the smart tap instead. Keep the trailer lights connected to T20/DTRL relay so it's really just controlling the trailer lights, stop and turn feature.. I think it would work but not sure which power and ground the OEM Relay would still need, or if anything bad would happen from it only controlling the trailer lights. Obviously the smart tap features wouldn't work on the trailer but I could care less for the three times a year I tow, no brake lights or turn signals on the trailer is a real problem obviously. If you could help with which wires the OEM Relay would need for just controlling the trailer lights I would be eternally grateful.

Pretty sure I had it, it's the one where you can't turn them off from factory, even with the headlight switch in the off position, right? I think my switchback LEDs are smart enough to know that some cars use low or high for drl, so even if it's a different filament that remains on it will switch to white after a second. It's weird because I thought of that originally but in my current setup the turn/drl bulbs are-
Off- off completely
Parking- amber for a second then white
Low beam- white

 

See post #12. Ask if it's still confusing.
P.S. it is not showing the front/drl and mirror turn signals.

 

I haven't researched exactly how the DRL and Tail mingle in the front turn lamps for taco's. I'm only guesstimating that since the driver isn't looking at the behavior of the filaments on the front signal to confirm, and you have replaced the lamps with switchbacks and an LED turn/hazard relay.
Do you still have the original OEM relay in original location not connected?