So here is how it went down. I pulled out the windshield wiper defroster button,and my volt meter. I slipped trying to hold all that nonsense and got a spark. Now the seat heaters ,all my windows including liftgate and sunroof,the blower-a/c and the wiper defroster.Nothing has power. I have checked many fuses and none seem to be blown..Anybody have ideas

2 FUSE BOXES- 1 is under the hood, the other in the driver's footwell. Something is blown. Sounds like a fuseable link under the hood- something more than just a mini fuse...

Why were you checking the defroster switch in the first place? Could this be a related issue with no power elsewhere?

I was looking for the hot wire on that switch so i could tap it for another new switch . going to put lights in the hood scoop. my switch has to lights one for dash lights and one for when its powering the lights

I thought it was common practice in Toyota vehicles to switch the ground? Only positive wire on the switch is for the illumination. No?

i was looking for the wire that illuminated the switch for wiper defroster. i was going to use that wire to illuminate my new switch and draw power from the battery with a new inline fuse to power the lights I didnt get very far. anyway there are five wires behind the switch.two witch should be ground and power for dash light and power in and out and a ground for the heater. ???am i right or wrong on my theory

Hi loafer,

I just grabbed a look at the wiring scheme for a late model 4Runner (2014) and it looks like you may have popped one of the Main body ECU compu fuses; that's the only common denominator between all of the circuits that you mentioned in your post. You can start by checking these fuses in the driverside Junction/fusebox. (1) DL2 25A (2) ACC 7.5A (3) ECU IG-2 10A, and (4) ECU-B 10A

I think that the MB-ECU just stopped communicating with the other slave ecu's so you lost control of a good amount of your accessories. I checked each fuse to everything that you mentioned but there's no connection between the power windows and the main blower for example, but all of their own ecu's are connected to the MB-ECU. Check those first and let us know what you find. If you can't find a blown fuse there, don't panic... I'll continue to search the electrical plots; too many to post up until I know which one is the culprit.

Cheers

When you said you checked the fuses, did you use a meter, or did you just look at the fuse. Sometimes a fuse can blow and look good. You should get a dead short on any good fuse with a meter. If you are reading a couple of ohms it's probably your leads. Touch the leads together with one hand (so you don't read through your body) and zero your meter. Do this every time you turn the meter on and want to make a resistance measurement. Some meters have a REL button that will zero it.

right on the money. thank you very much,everything works just like it should. and so you know it was ecu ig-2 the 10 amp fuse. i can rest easy before i hit the hay knowing my rig is secure thank a ton rigtec...

Hi Keith,

That was a dam good question!! You sent me back to the books to find the answer to your inquiry. You're right... most of our circuitry does use the 'Ground-side switching design'! But... the courtesy switch illumination circuits e.g., the Green wire at the switch is hot going into the switches LED, travels through and then grounds at the MB-ECU. Now the trigger circuit is allocated to the GND-side switching design as you have referred to! So there is a HOT line at ALL of those switches on the dash that are illuminated with the parking light circuit!

...boy you guys are bout to send me back to school lol! Thanks for that question Keith; I've been staring at these diagrams for the last hour just so I could give you a sensible answer! "Best to you!"