Trigger source for illumination wire, Prado 150 2014

[Redyellowcodbelly Lurker Find all posts View Profile Close Redyellowcodbelly]

Hi all, finally figured out why my back lights for all my climate control and and all the other panel switches aren't illuminating when the head lights are turned on. I recently installed an after market head unit, Vhedia is the brand and the left hand touch buttons weren't illuminating with the headlights, so I tested the illumination wire coming from the car, its a green wire, this connects to the orange illumination wire in the HU harness, to my surprise there wasn't a 12v reading with the headlights turned on, thus explaining all the other lights not working , I got the HU panel lights to work by running a wire from my uhf panel switch to the orange wire in the harness, so my question is, does anyone know what triggers the cars green wire to give it 12v and what fuse it runs off, was thinking the packing lights but can't find a fuse for them but my parking lights are working. Need to find the source of this dreaded green wire, any help would be gratefully appreciated.

Cheers.
Greg.

[GeeWhizz Senior Member Find all posts View Profile Close GeeWhizz]

It's complicated....

The Dashboard/Panel switch illumination is driven from the "TAIL" Relay. This feeds a 7.5 Amp "PANEL" Fuse, which connects to the beginning of the green wire, which distributes the illumination power through several Junction Blocks.

[ptommo59 Senior Member Find all posts View Profile Close ptommo59]

As Geewhizz said lots of things in play for the illum circuit and as well as what he listed there should be a Panel Relay in the engine bay fuse box that is controlled by the Body Computer (used on 2013-15 Prado 150 - 1KD-FTV w/ Entry & Start System models).

The relay is after the 7.5A Panel fuse and output feeds to connector GA1 (lower of the two large junction connectors in passenger side kick panel) pin 37 and then to the main junction block No. 3 (3A pin 64} located on the Instrument Panel Reinforcement right at the back of the dash so a pain to get to and gets distributed to various other places from there (Throughout its run it stays the dark green colour with no stripe)

If you get no illumination lights at all your looking at the items mentioned, if some work and others don't it is possible to isolate a likely wiring open circuit point using the wiring diagrams..