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

My thoughts exactly! I will do some investigating this weekend.

 

It is a small wire, probably only about 20 ga at most. Not sufficient to carry 15A. I don't know if it could be used to carry the other relay coil current - it goes to Pin 65 of Connector 3A - which goes to Junction Block #3, wherever that is (I couldn't locate it quite yet.) That pin is connected internally in the junction block to a whole bunch of other pins. So if connector 3A is already inside the engine compartment (which I think it might be), you can cut that lead before it gets into the junction block. If not, that lead can't be used.

However, here's what you CAN do:
Since the wire isn't big enough to carry 15A anyway, you could use the black or white wires in L8 to get the fog relay control (switch) line through the firewall. These two wires go to A10 pin 2 (black) and A39 pin 2 (white), which appear to be near the headlamp assemblies (IF those harness connectors are present in non-LED-equipped cars. I have not verified this.) So you would simply use one of those two wires to carry the relay coil "control" connection (whatever you choose to use, stalk switch or other switch) through the firewall. Again, this is all dependent on A10-2 and A39-2 connections being in place. I haven't looked yet, and we know that the fog lamp connectors are NOT in place (nor the wiring in the harness), so one of us will need to verify these are present.

The more I look at this, the more I think this is what I'll use (if they are there), and NOT use the factory fog fuse and relay circuit at all. This just gets you through the firewall.

 

If the wire can't handle 15 amps, and has to run to a relay anyway, I don't see the advantage of using the existing circuit.

I wish I could help more, but I just haven't received my parts yet, and I'm not expected to until mid next week - and that upcomming weekend is already booked up. It'll be three weeks before I have a real update on my install.

 

Awwww come on Mr. Prius Surgeon! You know there's no way you're going to spend 3 weeks wondering if that set of wires can get us across the firewall!

 

Maybe I'll find a little time this weekend to poke around in there...

 

hawkmoon, i am proud to say that my prius is officially done. My tech installed the factory harness(attached below) cost was only 63.00 and no additional pins,connectors were needed( i returned the other connectors and pins that were previously bought). Also the only modification in this whole process was one lead from the fuse box under dash(connect to fog lamp relay) to the harness at lights. The tech said all further installs will take only 3 hours now that he knows that everything is already there in the car and waiting.I will follow your thread closely . If you find the "missing link" between the lights and toyota fog lamp relay i will certainly pull the added wire out and gladly plug in. Now, how do we heat our cars in the winter using the solar cells? : ) . Thanks for your help and encouragement

 

Glad it all worked out. As far as your heating question, the answer is to park in the sun! On a 30 degree day, temps in the car get up to 60 plus degrees inside... of course, I do live in Florida, so that may have something to do with it! It may not use the solar panels, but it still counts as solar heating.

 

Thanks CASUMIK, that (especially your parts list) sheds some light on what your tech actually did. It appears he went to the 2C pin 8 connector using a different pin than Toyota specifies for that connector (82998-12440, see attachment below). It definitely is a different connector pin (compare to rachaelseven's post with the photo.)

I'm also pretty sure that it isn't truly locking in place like the other one - it isn't the same lock type. It's probably just slipping on to the mating connector blade, with no lock. But maybe that doesn't matter much, since that wire shouldn't really get tugged at, in normal use. I hope he wire-tied it, though.

So he plugged that pin into 2C-8, and ran a wire (carrying the switched 12V) from that through the firewall, to your new harness at the fogs.

Do you know exactly where he went through the firewall? Any chance of posting a photo, if you can find it?

Thanks for the info!

 

Wasn't that pin on the parts list because the tech had planned to use it at the headlight connect before finding the harness? Looks like a negative quantity of those pins (returns) on that invoice. Unless I am misunderstanding something, that pin was all about the headlight connection and wasn't involved in the connection to the relay, right? Which of course leaves the question of how did he hook up to the relay without the right pin?

 

You know, I think you're right. When I looked at the pin drawing, it is so close in dimension I thought it might be what he used. But I didn't notice the negative quantity. So yes, how in the heck did he connect to the pin at the relay output?

CASUMIK, I think you mentioned in a previous post that he drilled a hole into the into the fuse box, or something like that - was that under the dash?

If so, I don't think that's anything I'll be doing...

 

yes,those pins were returned. I have known this tech( master tech) for over 20 years. He is as anal as I about fit and finish. I will ck with him on Tuesday as I will be down there for a truck repair and find out how he connected to the relay. I am certain it is tight and properly done. Also will find out where he went thru the firewall , I suspect thru an existing hole.I will post a single shhet w/all the part #s as it has gotten confusing w/all the different ways of doing this. I wanted all Toyota parts to be safe but will admit it has been expensive.more later!, mike

 

Oh yes and the fuse box and drilled hole are under the dash

 

I Have finished mine too but mine is wired separate from any internal wires except the relay trigger and the main power. Is your's wired through the ECM? Do you actually get a green indicator light near the headlight indicator on the dash? I have a separate switch in one of the blanks just above the panel light adjustment. Did you install the turn signal stalk? I was afraid to tie into the car wiring too much because of potential warranty issues.

 

I am trying to add some pictures to this post. Hope this helps.

 

Hey! How did you solve the firewall crossing problem? And the switch looks nice, where did you find that?

 

Well, I had my front bumper off this weekend and looked for connectors A10 and A39. No luck. It appears those are not part of the harness if you don't have LED headlights. Bummer. Back to finding a path through the firewall.

 

Slovewell, great switch! I'd like to know where you got it, too!

 

Bummer indeed. Thanks for letting us know though.

 

Switch info please op2: