2008 Taco Junction Box Questions

Intermittent complete power loss. Been to three mechanics and no successful fix. Two of them came up w the problem being the junction box. Pulled it down to see if I could see any loose wires or anything burnt and found relays on the back side of the box. Anybody know what these are for? I can’t find a description of them anywhere. Thanks

 

Do you mean this:

 

Yes that’s it

 

ACC = Accessories
T = Tail/Parking
PW = Power Windows

 

P.S. There's no "repair" for the box, remove & replace is best.

 

The part is so pricey tho I’ve already paid over $2k between the three shops and it’s still doing the same thing as the day I brought it to the first one. It’s sad. I just don’t know if I’m willing to dump another $1k into it when I’m not sure it’ll even fix the problem. I’m btw a rock and a hard place. I was gonna drop the box and pop it open, see if I could see at least some clear indication of failure. I’ll replace it if I can get some kind of confirmation it’ll actually fix it.

 

My truck is a base model so I have zero bells or whistles. No power windows or locks, no cruise, nothing. Automatic trans tho.

 

Find a willing friend with same year Taco, swap box to test.

 

That would be awesome, but I just don’t know anyone of the sort

 

Rear of box, opened...

 

And then one has this to deal with:

 

Yeah that’s the issue. Is there a test to confirm the box is bad? Other than ruling everything else out?

 

You could test every pin for continuity, but you need the schematic of the routes. And also follow the rule out procedure on the repair manual. Also, there's no schematic for the ECU pcb for proper testing, a least none that I'm aware of.

 

Yeah that’s beyond my scope of knowledge ‍♀️

 

What exactly have the mechanics said about the BECU being the culprit?

 

Just that they’ve tested everything else and it’s “gotta be” that. The last mechanic had my truck for almost three months. I finally went over there and cornered him bc I couldn’t get a call back and he gave me the part number, told me it was on nationwide back order, and told me that if I can find it and get it, that he’d install it for free. This is after he got it missing two relays from the second mechanic, replaced those, charged me $500 and sent me out only to have me break down a mile and a half away. I just had it towed back to my house.

 

I found the part in 30 seconds btw, very available.