Well, it's been an interesting couple of days...and not just because I got a $20K quote for the paint and body repairs that I'm electing to have done on the Cruiser. Note the key word, there:
electing. I didn't know that outside of the world of classic Italian/German sporting vehicles, one could
elect to have twenty grand of minor paint and sheetmetal repairs done that are not even remotely necessary...but evidently, that's totally a thing. But, I digress.
Having realized that I may not be able to get non-diode relays in time to actually
use the results of this project - and I'm on an ever decreasing deadline that's being bolstered by a series of gratuitous extensions - I elected to swap the ground and input sides of the relay block, so that I can use either relay option; a standard relay should work with the trigger in either direction, and a diode-relay should be perfectly happy as well. However, due to the larger wire gauge that I used for that portion of the wiring, things got cramped and difficult behind the block itself...so I ended up rewiring it. Now, the 24V trigger circuits are in the same 20AWG as the taillight harness, the ground for those circuits is pulled from the same harness, and the 12V power is being run into the same connector...so I have only a single path of wires going inward. It's cleaner and neater.
Pictured: The new hotness.
It's actually very hard to tell what's going on there, but that's the intermediate taillight harness on the upper left and the 12V power wire on the upper right. They're both cable-tied to the exterior metal, and the weird arrangement allows everything to be unclipped and removed with minimal fuss; it's the best I could do with leads coming from both directions. You can see the driver's side intermediate harness a bit better.
Pictured: Not factory, but close.
It's a pretty simple arrangement on this side: four factory-ish-colored wires that pass directly through from one connector to another, and one with a Y-splice - the right turn signal - that leads off towards the passenger side. That's the braid-loomed bit...and no, it was not easy to get it from one side of the vehicle to the other without placing it anywhere in danger.
Pictured: Witchcraft may have been involved.
All other signals - and the ground - come from the passenger side; that configuration uses the least amount of wire, and has the least chance for failure. After that last pull was completed and the left taillight intermediate harness was buttoned up...well, it was actually pretty underwhelming.
Pictured: But there was much rejoicing.
It's almost impossible to get a photograph of the relay block output harness; it's buried in the lowest, sub-basement corner of the tub, and it exits from where Toyota placed a convenient rubber grommet through the sheetmetal. Best I can do is show the upper section, which actually shows the intermediate harness that I built more than anything else...
Pictured: But there's some more below this, I promise.
That other loomed wire is the ground, which is running directly from the 12V fuse block. It looks wonky in the photo, but it's actually pretty good when you look at it in perspective...and of course, it's all hidden once the trim panel goes back in.
Pictured: It's not so terrible.
I'm not displeased. And the exterior part of the harness was actually pretty easy to install and route, because Toyota already ran harness-parts underneath the body in the back...so if you just follow that from the through-panel grommet back towards the center of the vehicle, you'll get a pretty clean and simple install. I'm not sure that I got a picture of that part of things, because I was in a hurry to test everything out and make sure that my replacement relays worked...
...
...
...which is exactly what they proceeded to not do.
To be completely honest, I'm not sure what went on; I got a set of four non-diode Bosch relays, checked them for function, revelled in the gratuitous clicking that came from the block, and went on about my rewiring and everything else that I've already covered. But when I plugged in my trailer light checking dingus: nada. The running lights worked, but the brake and both turn signals were non-functional. I also bought a replacement diode relay and exactly one (1) of the correct Hella units, just to check them out. I tried swapping in the Hella and got no change at any position...but when I swapped the diode relay into the brake circuit: turn signals started working. I'm not sure what's going on with that, but I suspect that now that I've swapped the grounds and inputs, I
have to use diode relays. That admittedly makes zero sense to me, but when my replacement set of diode relays showed
up - I think I'm up to about ten total relays, now - I threw them in and checked it all once more to see if i finally had any function. The result...
