No brake/running lights, no dash lights, no HVAC, 4HI, 4LO, TPMS, etc lights on - SOLVED

I picked up a 06 DC a few weeks ago to “downgrade” from my holy grail truck. Had a 2021 TRD Off-road Tacoma with the manual that I bought new. Loved that truck, but building a house and wanted to cut debt.

Ran into a recurring issue that went away on its own previously, but couldn’t clear this morning. Both indicator lights for 4HI and 4LO were on, both on the button and the dash. No running lights, but I could get the headlights on. No brake or tail lights. TPMS light on, and probably others. Gauges were reading, but the bolt gage was hovering around 9v.

I checked fuses and all seemed good. On a whim, I unplugged the brake controller that came in the truck when I got it. Heard a few relays click, and looked to see my dash come back to life! So far so good, but basic troubleshooting prevailed. Go to the last thing touched, and start eliminating non-factory items.

 

So now no brakes?

 

I think he’s referring to aftermarket trailer brake controller.

 

That’s what I meant.

 

I think failing brake controller is probably a cause of a lot of vampire drain issues too. My faith in them is on par with my faith in aftermarket alarms.

 

I kept the redarc system I previously had in the taco, I’ll get that installed eventually. Way better setup. The one that was in there didn’t appear to have a discrete ground wire, probably the source of my issues. We’ll see when I dig into it further.