c foglights

That was useful, Thanks for your help!
I managed to find the FOG FR fuse mentioned in the diagram, I'm surprised that the fuse is actually there. What I can't seem to figure out is how to get to the relay(s), or where the fog light harness comes in. It sounds like the TAIL relay might be up behind or inside the computer that's above/attached to this fusebox. Does anybody know? PartsNinja, do your awesome manuals show anything about the location or specific connectors/pins relating to the wiring diagram?


Depending on what I find from here, My plan is to get to the output of either the fog fuse or relay. I would then wire a switch to one of the blank spots in the dash. I would use the switch as either a substitute for the relay or FFGO. The LED wire BE would be trivial to light up additionally if it's in the same location.

ROLOPR: I might suggest you doing the same- using the switch of your bezel hand wired to the same location of interest.

 

My kit arrived today, just waiting until Saturday for install ... Looks great BTY !!

 

Post it when done, any info regarding installation is welcome, specially where do you installed or by yourself

 

I thought I'd let everyone know I finished my fog light adventure.
I can confirm with the prius C TWO that you do not need any wiring harness, extra relays or fuses. You can tap 1 wire to 2 wires about 2 feet apart behind the passenger fuse box, connect a switch lead into to the fuse/relay/computer box and your in business to use the built in wiring, relay, and fuse.
I didn't hook up the foglight indicator led in the dash yet, since the wire+pin was not populated in the connector- I will have to figure out how to open up the display unit area.
Also, for those who have attempted this route with dealerships or the like and stuck at needing an expensive computer change, you simply need to solder two pins inside the relay box together and everything will connect together and work.

I will post some pictures etc soon.

 

Great. Thanks Kwhubby. I look forward to your photos. About to order a set for our c-2.
Dan

 

Just got the fog kit today. I looked at the diagrams, and what I want to do is to connect two wires from the back of the interior fuse panel. One wire will connect to the tail light (fuse #1) and one wire goes to the fog light (fuse 21). I intended to use one of the relays supplied with the kit, but, if the fog relay is aleady there, I could use it instead.

I want the fog lights to operate whenever the lights are on, including parking lights. The "aftermarket stock" setup will not allow this, and is more complex because of this.

My question is: how hard is it to get to the back of the interior fuse panel? You did this, Kwhubby, right?

Will your hookup, Kwhubby, allow the fogs to be on with only parking lights? Can you be more specific about the connections you made? Thanks.

 

So the stock has 4 positions: off, DRL, "parking lights + drl(when car is on)"?, on
My fog lights turn on when you get to the 3rd position when the tail lights, license plate and front small indicators are on (and the foglight switch is engaged of course). You can see in the schematic that the fog lights can only be activated when the tail relay is engaged. High beams do not disengage the fog lights. As you can see from the schematic the highbeam foglight disengage function is a feature of the headlight dimmer switch assembly.
I can’t seem to post pictures here right now, so I am writing a how-to webpage. Here are written instructions (these might be of use if you can cross check with a meter and the schematic)

The interior fuse box is pretty easy to remove, open, and modify. You need I think 10mm socket, and a mini flathead screwdriver to disengage the tab on the connectors. You will have to remove two 10mm sockets (one might be tricky to get at) and disengat You will have to unplug 3 multi pin connectors from the front of the box and the large power connector, 2 connectors from the rear, and likely connectors to the left-wise adjacent computer box that are on the same wire bundle.
For use of a switch without the factory wiring connectors, you will want to solder to pin 13 of the computer header. Route this wire out of the box to connect to your switch in dash. Grounding this enables foglight use.
For the output to the factory wiring harness, on the gray connector that attaches to the front of your fusebox, on the rightmost column of pins, tap onto the blue 3rd populated wire down from the top (4th large pin down if you look inside the fusebox jack).
You need to connect this wire to two blue wires on a connector that is on the left wall of the inside of the car behind and slightly below the computer box labeled E. If you reach behind and disconnect the lower of two connectors you will notice two blue wires that have no corresponding pins in the jack. These go to your factory foglight wiring, the black wire has a corresponding pin and provides ground already.

 

If I understand you correctly, the connections shown on the schematic are not all there for the I,II and III models.
Namely, pin C3#7 is not connected to the fog wiring, which is just tucked away. Also, pin c3#23 does not connect to the dash panel, pin 12.

What I thought would work is to connect to the the green wire of the light stalk connector which goes to pin 27 of the ECU. When this is pulled down, I thought that the ECU would pull down pin 13. Doesn't this work? Wouldn't that be simpler than soldering to pin 13?

It's too cold here to do any of this today, but I want to be ready to do everything on the first warm day. I know that the approach you took is much better than the ugly setup with two relays that came with the kit.

Thanks for your help, kwhubby.

 

Actually the pin 7 you mention is a blue wire on the front gray connector, however it doesn't go anywhere- hence why I tapped it to the foglight wire harness which is tucked behind on the side.

the ecu DOES NOT pull down pin 13 when 27 is pulled down- I tried that first. My alternate suggestion to wiring out pin 13 from the computer header is to connect pin 13 and pin 27 together, so that way you pull down 13.

 

So, C3#27 doesn't activate the fog relay?? I think this is the same ECU as in the Prius C4, so what are we missing?
The ECU must need another signal (like low beams on?) to pull down pin 13. The only other connection shown on the diagram goes to the taillights (ECU pin 30). Did you have lights on when you tried it? You sound pretty thorough, but I just want to make sure.

Did you say that there was no wire between C3#23 and dashboard indicator?

I reworked the switch that came with the kit. Now it is illuminated and , when pressed, indicates that the fogs are on. This required taking the little switch board out, removing a diode, soldering a wire inside, and moving the power (illumination) from pin 2 to pin 5. Looks good. I don't really need the dash indicator too, but if its free... why not.

 

Just pulled the trigger and ordered the lights. I appreciate them putting the instructions up for us to look at. I have studied them a good bit and will wire mine using them. Thanks for all those who have posted in this thread. This is a good price for these lights.
Dan

 

Yes I did test with the lights on, it seems Toyota intentionally programmed the controller to ignore the fog light signal on C2. It's not a big deal to bridge the two pins unless your completely opposed to any non-stock/factory wiring or modifications. It's a hell of a lot easier and cleaner than routing wires to your battery and through your firewall like the kit recommends, IMO.
There also is no wire populated in the connector for pin 23. Pin 23 and 7 share a trace on the relay board, and since there is a wire populated on pin 7, without further soldering or special pin tools you can just tap the wire coming out on pin 7. I don't know about the dash- there may or may not be a wire populated for pin 12. opening it up sounds fun- I'd like to change the turn signal relays anyways for future led replacement.

 

What about the Stalk instead of the standard switch kwhubby? I'm still lose with all this (non electrical user :S)

 

I'd love to see the How-to webpage when you get it done.

Thank you

Kevin

 

I created a thread on my whole project:
Custom LED foglights for my prius C trim 2. | PriusChat

For the wiring how-to hopefully this is useful (it could be a tad more thorough): Custom Prius C Foglights (pictures, and instructions)

ROLOPR: As the schematic shows, the Stalk is supposed to have a wire to toggle the foglights lights. You need to identify this wire. Does this wire make it to the pin 27 (FFOG) on the ECU? It won't unless you have a bunch of interconnecting wiring harness stuff- or a way to insert pin 27 into the connector. If you have foglight toggle wiring making it to the fusebox you can solder pin 27 to 13 on the ECU header. Otherwise, I'd suggest what I show in my webpage: soldering a thing gauge wire to pin 13 on the ECU header (note my write up), routing it outside the box and connecting it to what little wire you may have coming out of your stalk.

 

Job Done !!

 

Do you do it yourself or where do you do it?

 

Yes !!! I did in my house, just followed the instructions and a lot of patience.

 

Ok let see If we can meet later.

 

I installed the kit tonight.

Here are my takeaways that I think will help others.

Use a floor jack to get the car off the ground. Initially, I used ramps, but there was no room to work in order to run the wiring into the firewall. I eventually took the wheel off and most of the fender liner clips. You only need to remove the front left wheel.

Wear gloves when removing the old foglight trim pieces. I gashed my finger trying to yank it out.

This is probably common sense, but make sure to connect the wiring to the positive battery terminal. Connecting it to the negative terminal supplies direct power to your headlights.

For tapping the connector wires, take out the connector and pull it towards you. I also unwrapped some of the electrical tape. You want to tap the thicker of the two purple wires and the pink wire of the same size.

If anyone needs further help, feel free to message me here or email [email protected]

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My question: How do you reinstall the battery cover clips on the rear seat? I can get them in, but I can't figure out how to get them to click in place.