DRL Failures, Locker Indicator Flashing, and Chasing Electrical Gremlins

So, since this post got the bump, no update on the testing or light internals but I’m planning on baking open the faulty housing this weekend so I’ll take some photos and do some testing on the board itself.

Toyota also never sent an arbitration package but the necessary information can be found in the owner’s manual. I’m still considering arbitration, particularly since Toyota recently replaced another members 4th driver’s side headlight with heavier electrical mods than mine. That being said, I’m enjoying the truck and the dealership still treats me well so I may just bite the bullet here and wait until something else goes wrong before pursuing this further.

As far as replacement lighting, I’ve had the Morimoto XB housings installed since early January with no issues. Also installed a power tray and blue seas fuse block so all new wiring is (and will continue to be) very clean and easily traceable.

 

C’mon Toyota. None of my mods could ever had messed with the factory electrical system. I hooked it up myself, real good

 

Well, first thing you notice is the boards are different:



Also...the new board works:



More to come.

 

Tested each LED chip on the old board and they all worked. Must be the driver, nothing noticeably damaged though:

 

This is the only “potential” visible defect on the old board:

 

Had to remove a little alignment tab to get the new board to fit. Didn’t seem necessary anyway. Each chip fits in the optic properly, each screw fits, and the other alignment tabs still function:






Did a hack job opening it up, and used a TON of retroseal rubber to seal it back up. Still need to polish it out but the new board works:



Not sure what testing I can do on this old board, if any, but I would be interested in finding out why the boards are different and if they came from different suppliers or different batches or something along those lines.

 

pros have different boards from what I understand

 

I wonder if the pro board is functionally different in any way?

Its in there now though and not coming out again! There’s no way I’m messing with this housing again that’s for sure!

 

Got a good pic of the other side of the white board?

 

The pins on the boards look to be the same old to new. It just appears to be the colour. Is it possible that the black would be for the dark style headlamps and the white is for the chrome style headlamps. It also could just be manufacturing changes. I will check my truck in a bit and see if I can see what colour the board is.

 

The pins do appear to be the same, but it’s clear that there are different batches of DRL boards now. I wonder if Toyota did any actual testing on my previous failed boards or can track them to a specific batch/supplier/factory/etc.

 

Oh. Both black on the LED side. My theory is bunk. Please ignore it

 

Haha no problem, you also can’t see the board from the front of the headlight. Can probably see board color from the little inspection port underneath the headlight though.

 

The new board also seems to have a similar “circle” so that leads me to believe it’s not the failure point.

 

Circle looks like a qc stamp to me.

 

Looking back and forth I don't see any real major differences, but its hard to do on a phone. To really know you'd have to get down to it with some test equipment and ideally, schematics.

 

So just a little more "diagnostic" information for anyone following along.

In moving the original Baja Squadrons to the ditch light position I found that they are are internally grounded to the housing and can/will light with only power to them if the housings are well grounded to the chassis. To make sure this wasn't a fault, I called Baja Designs and confirmed that they are designed that way. They will also not light if the polarity is reversed so reversed polarity was definitely not an issue.

Not sure if this makes a difference at all but I suppose it could have lead to some type of grounding loop and that signal noise that Toyota was alleging. Those squadrons have now been moved up to ditch light brackets and the fogs have been replaced with a pair of Baja Squadron SAEs.

Still zero electrical issues since replacing the headlights with the Morimotos.

 

OP: This is too much to read through, but it sounds like
you made progress. Do you mind summarizing what you learned about the cause?