Fog Lights: Install [Retrofit] fog lights on 2010 Prius?

Good news. Let us know what you find.

 

Unfortuantely, even that won't get you past the firewall. I verified last night on my IV that the lead coming from the relay output (Pin 8 of Junction Block connector 2C, under the instrument panel) is not present. So you still would have to run a lead from that pin through the firewall. (Maybe the dealer could run the new lead through the firewall - for more $$)

Another thing to consider if you use the factory relay and stalk switch or its lead: I noticed when checking this that the fog power (through the factory relay) is NOT available with high beams. I understand why this is - you wouldn't be using high beams in fog. But sometimes on dark rural roads, it's very nice to use both - deer crossing can come from anywhere - far away (brights help) or very close and to the sides (fogs help).

Just something to consider.....almost makes me NOT want to use the factory circuit.....

 

DOT laws prohibit running high beams with fog lights, and likely require manufacturers to wire them in such a way to help you avoid getting a ticket, which I am sure would not be a problem on a loany deer crossing laden road as long as you lowered your high beams for the oncomming police cruisers.

Since factory fog lights are generally not as effective as the brightes legal aftermarket alternative, it seems like it would be fairly easy to get some small round fogs to fit in the circle cut out area of the gray plastic boots.

 

I am pretty sure that i will use the factory cicuit, but not 100% sure. Iw ould still use the factory stalk, no matter what, but i'm not sure how I will handle the wiring. I like that the stalk switches ground. If ever the wire that ran to the lights shorted, it wouldn't be a big deal at all. (The worst that would happen is that the lights would come on, indicating the problem. Much better than if 12V+ went to ground).

 

So, to keep aftermarket installs legal, we'll need 2 relays??:

-an SPST as normal for the switch to the lights. 87 to the lights

-an SPDT to toggle from the low/high beam to power the switch? Low beam to 30, high to 86, 87a to the switch

This way, they are only on when low beams are juiced and highs are off? Turn on the highs, trip the SPDT relay to close it, dropping power to the switch, killing the fogs, but the low beams are still on.

 

I'm about to just put the fog lights in and not even wire them up. 100% poser

 

I may be there yet with you before it's all said and done. Until today's reading session and the post above about the junction box, I had assumed that the existing relay was in the engine compartment. If using the factory stalk won't at least get me to the engine compartment junction box, it hardly seems worth it... especially since the switch that comes in the eBay kits is a perfect fit for the Prius knockout. Ugh.

 

It would be easier, by far, to just use the toggle switch (included in the Ebay package) that fits perfectly into one of the unused Prius switch positions - and would not require such a risky task as removing the steering wheel.

 

Careful - The stalk lead does switch ground, but only to the ECU as an "input" (pin 27 of L7). The ECU then has an output (which is internal to the junction box) that provides ground to the "low side" of the relay coil. So the line running from the factory relay to your fogs and through the firewall is 12V, not ground. Your ECU is safe, since it's only grounding the relay coil - but the firewall lead can cause damage if it gets cut/shorted/etc.

You certainly could get 12V from the engine compartment and add another relay inside, to switch in the lights' ground, getting its 12V relay coil power from the factory relay (!).

Yikes.

Also, I did a quick (definitely not comprehensive) search on federal DOT regs for fog lights. I don't believe there is any federal regulation regarding fogs (or any other auxiliary lights). I do know there are state or municipal regs, which all of us would need to check ourselves. A link regarding federal regs:

Regulations for Front Fog Lights | eHow.com

Hope this helps.

 

Also, keep in mind the factory fog circuit is fused at 15A. if you use it, you either need to:
- Install wiring that can handle 15A (16 gauge or heavier);
- Use the inline fuse that comes with the fog lamps, if provided (which needs to be less than 15A); or
- Change the factory fuse to a lower value, to match the wiring you use.

You don't want to risk melting or burning up the wiring alongside your lead or inside the factory junction box. (No matter whether it's carrying the 12V or ground path - they'll both get hot. Current is current.)

 

Did your dealer ever give you the connector/pin part number information and relay location? I think I've got the right bits located in TIS, but it would be great to get a professional confirmation. Thanks!

 

If you have a second in TIS, can you see what color wire goes to the overhead console LED...LOL?

 

If I had any idea what they call the silly LED thingy, I'd be happy to look it up

 

or sunroof power

 

The relay is there,a lead has to be run from the relay to the lights and your done. All other wiring is there. I posted the correct connector #s on an earlier post(I am posting from my phone now so cant link back to that page).the problem now is the tech couldn't find the proper pin for the connectors. He has called toyota and I expect to know soon. My lights work perfectly( they are spliced in and my tech and I both want a factory fit. I don't think he drilled any holes in the firewall but did in the body ecu/fuse box.I have a diagram at home with the relay position and will post tom.. I have to stress that I am a non electrical genius.so you folks will understand it better than I . The lights themselves are perfect. Nice wide beam. In Indiana it is not legal to use both high beams and fogs.course it sounds as though some of you want driving lights rather than fog lights,they would provide the distance and brightness on a clear night but would be horrible in fog.hope this helps

 

the connectors needed for the fog lamps are part #82824-60460.the pin part number I hope to have tomorrow,sorry for the delay

 

Thank you very much and no apology necessary! That is the part number for the connector at the light itself, correct? I believe we also need a pin for the connector at the junction box to get the power from the relay, don't we? If I'm reading the wiring diagram correctly, it should be pin 8 of connector 2C and it requires Terminal P/N 82998-24350 & Press Sleeve P/N 82999-12030. But then your guy seemed to be indicating there was a hole to be drilled in the junction box? So maybe he didn't grab the power at connector 2C?

Would be very helpful to know the details of this part for those of us intending to use the factory stalk switch, so can the dealer also confirm that information for you? Thanks!

 

The parts dept. that I ordered the RH fog light cover from just told me that they are on "national backorder" for whatever that means. They said they are not set to be restocked until 9/17. I asked that the other parts be shipped asap. We'll see.

 

I did a quick test on my car. I conected pins 3 and 4 of the wiring harness with a paper clip to see what happened. I definately heard a relay click when i shorted the pins, and that relay was comming from under the dash, not under the hood. So it does seem like a wire will have to be run through (or under) the firewall. Also, it seemed like the relay would only activate if the headlights were on. (I'm not 100% sure on this).

 

Sounds about right. The location diagrams on TIS put the relay in the Instrument Panel Junction Block, just to the left of the steering column (I think?), under the dash - definitely not in the engine compartment. Only the 12V wire needs to be pulled from that relay forward, but it seems we'll still need to cross the firewall with one wire