OEM-quality Fog Lights on '10 Prius will not shut off

Discussion in 'Gen 3 Prius Accessories and Modifications' started by GoldPianoGarden, Nov 25, 2014.

  1. GoldPianoGarden

    GoldPianoGarden Bling Meister

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    I bought the OEM-quality fog lights from the site's Prius store a while ago and had them installed. Two days ago, I was walking down my drive in the middle of the night to get the newspaper. My car was parked right outside the garage with the doors locked. I was startled to see that my fog lights were on....even though my car was off. My car had been sitting outside for 2 days due to a brief cold snap we had here (I had filled all 3 of the garage parking spots with thousands of my super-tropical plants so they wouldn't be hurt by the cold). Thinking back, this was the first time in a really long time that I have even seen my car in a nighttime/dark setting, so no telling how long my fog lights have been going without ever shutting off. I only drive my Prius about once every two or three weeks, so it usually is sitting in my garage. Anyway, I have turned it on/off, locked/unlocked it manually and with the remote, driven it up and down the street, turned the lights and the fog lights on/off in every possible combination, etc., and the fog lights simply will NOT go off. Nothing happens when I push the fog light button on the dash. When the car is powered off, the fog lights dim down to approximately the output of a 7w household nightlight. They brighten on up to their normal intensity/output once the car is powered on. I know NOTHING at all about car wiring, so I don't have a clue what might be wrong. Thankfully, I replaced the Prius battery with a more powerful one a while back; otherwise the car battery would definitely be dead by now. The dealership can't even look at my car until next week, so I would love to know if any of you might have any helpful ideas on why the fog lights will not shut off. Thanks for any input!
     
    #1 GoldPianoGarden, Nov 25, 2014
    Last edited: Nov 26, 2014
  2. xliderider

    xliderider Senior Member

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    The installer must have wired them in incorrectly. If properly wired, the relay would not be energized when the car is shut down.

    Also, even if the foglights were wired so that it is possible to turn on the foglights when the car is off, the dash switch would still be able to turn the foglights off.

    Take the car back to the installer and ask them to correct the wiring.

    SCH-I535
     
  3. Accordlayingkit

    Accordlayingkit Senior Member

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    That sucks man! Wish I could help but I know nothing about wiring either! Im sure one of the smart guys around here will chime in soon.
     
    GoldPianoGarden likes this.
  4. kc410

    kc410 Active Member

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    The fog light switch controls a relay, which in turn actually provides the 12V to the fog lights.
    It could be that the relay is not fully releasing when the switch is turned off.

    One side of the relay connects to a 12V fuse & the other side feeds the 12V to the fog lights.

    The easiest solution is probably to visit the installer & ask him to troubleshoot the problem.

    As a temp. solution, removing the relay from its socket or pulling the 12V fuse feeding the relay would turn off the fog lights, giving you time to plan a visit to the installer. Problem is - finding the locations of these items is not going to be easy :(
     
  5. Easy Rider 2

    Easy Rider 2 Senior Member

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    Make that 3 votes for taking it back to the person who likely caused the problem in the first place.
     
  6. GoldPianoGarden

    GoldPianoGarden Bling Meister

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    Hey, thanks for your reply. Yeah, it's gotta be that relay thing that you describe just not doing what it wants to do. They were installed to turn on and off with the car. I have always left the switch pushed on, and I have used the lights as driving lights. They've always shut off when I turned the car off....until now. So, whatever has "shut the power off" to them has just stopped doing its job correctly. So....next issue. The installer, that I have used for 20+ years, closed up shop in the middle of all the installation of my many electrical items that I added onto the car. Very little of my electrical stuff got wired up. The wires are all just tied up inside the engine bay. Anyhow, moral of the story, I no longer have an installer. I took my Prius to the Toyota dealership this morning and dropped it off. Is this "relay" thing a "universal thing" that the dealership would have access to and could repair/replace? Or, since I bought the fog lights from our Priuschat store, would I be have to somehow get a relay from the Priuschat store, or would I be stuck with having to trash the fog lights and buy all new ones (which I hope is not the case, as I sent them off previously and paid to have various LED lights installed in them --- which of course have yet to be wired up)?

    I had hoped to post a response earlier, but I managed to get my very first computer virus last week, and I've spent every free second on the phone with Microsoft while they've been in my computer remotely, trying to completely remove it without having to do a complete reinstall. So, I'm actually sitting in the dealership lobby right now using their computer. lol! Anyway, I thank you all for your help with this and for taking your personal time to respond to me. I look forward to your responses and help!
     
  7. Accordlayingkit

    Accordlayingkit Senior Member

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    Dude you have all this stuff done to your ride and no smart phone for the Internet!? (n)
     
  8. xliderider

    xliderider Senior Member

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    How long has the relay/foglights been installed to come on with the car? My relay for my DRLs failed after 6 to 8 months wired up that way. I found the relay contact had carbon on it from arcing most likely due to chattering during voltage fluctuations at startup. I replaced the relay and also installed a delay timer relay on it to power it on after a 20 second delay. It's been ok ever since.

    SCH-I535
     
  9. kc410

    kc410 Active Member

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    The relay is a standard one. Toyota should have minimal problems finding the relay & replacing it (keyword "should").
    An idea if needed: with the Prius in Ready, turn the fog light switch on & off rapidly & follow the sound. The relay should make a gentle "click" noise every time it operates.
    With just a touch of luck the Service Tech has got it repaired by now :)
     
  10. GoldPianoGarden

    GoldPianoGarden Bling Meister

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    Hey again. They've been installed over a year now. Well, of course, the dealership just called and said they've done everything imaginable, but that my fog lights shut off and turn on just like normal. Isn't that ALWAYS what happens when you take your car in? Now they say that they can't get the fog lights to stay on continuously like they've been staying on at my house for the past week. Of course, the lights were still on when I got out of my car at the dealership. I checked that right away, just in case my car decided to pull a fast one and "act right" for the mechanics. Just like always happens, they drove my car around to their mechanic's bay to be checked out and the fog lights suddenly worked just perfectly. But you know they'll stay on continuously again the minute I get my car back to the house... How frustrating! I asked the dealership how much "the relay" cost, in case you guys said that my relay would be the same practically as a Toyota one (waaaay above my head!). They said $106. They said that the only relay they could see, though, would be the relay that somehow connects to/with the headlight switch...I think. I personally can't see how the fog light relay would have anything to do with any relay that is associated with the headlights. However, I'm trying to imagine all this in my mind, and I understand none of it... I did suddenly remember some other fog light "behavior" last week that was weird. One time when I got out of my car, during my many attempts last week to get the fog lights to shut off, the fog lights flickered up and down between bright and dim really fast for about 5 -10 seconds after I shut off the car, kinda like a fluorescent light will do that is in the process of dying. I don't think I had recalled that fact in my previous posts here. It just came to me earlier. Anyway, is that how a relay would behave that is going bad? Also, this "relay" that we are referring to, is it something that came with the fog light kit? If so, this relay could be installed anywhere in the car? I know that the installer ran the wires thru the firewall. So, the relay would be....inside the dash, back behind the fog light on/off switch? or somewhere in the engine bay, never to be found again? Thanks!
     
    #10 GoldPianoGarden, Dec 1, 2014
    Last edited: Dec 1, 2014
  11. xliderider

    xliderider Senior Member

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    The relay would not be a Toyota one, it would be a generic Bosch style automotive relay that any auto parts, stereo store, and Radio Shack carries. They sell for $5 to $8.

    It is most likely mounted somewhere in the engine bay, along the wiring that comes from the firewall that goes into your engine fuse box. It is a plastic black box about 1 inch square, that might have a tab sticking out one side that may or may not be screwed/bolted down somewhere.

    SCH-I535
     
  12. kc410

    kc410 Active Member

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    I have the same fog light kit from this site & its still in the box. I looked at the wiring supplied with the kit & can "relay" the following info (couldn't resist)...
    Under the hood, on the drivers side is a fuse box. If you release the latch at the bottom of the cover & lift up, the cover will hinge at the back & remove as you lift.
    If its wired as the instructions suggest, you will see a red wire going to a white connector plugged into the top of this fuse panel.
    This is the +12V connection from the car.

    Follow this red wire for 20" - you will find an inline fuse with a rubber cover. This is the fuse for the fog lights.

    About 4" away from this fuse is the fog light relay (the fuse & relay are connected via a 4" length of red wire).

    It has a mounting tab at its top & may be screwed/ty-wrapped to something solid.

    The connector on the wire harness has a latch that must be depressed to disconnect the relay from the harness.
    You need to find a replacement relay - try any autoparts places, Autozone etc.

    Info: The relay must operate to close contacts that supply +12V to the fog lamps.
    It seems the relay was not releasing completely & this would cause the fog lights to be dim when the Prius was powered down.

    Just turning the fog light switch on & off 10-20 times could easily have caused the trouble to disappear as the contacts self-cleaned.
    The relay needs to be replaced even though it may not be acting up at the moment, it could stick on at any time & drain the aux 12V battery.

    I will try to attach a pic of the fuse block connector/fuse/relay...

    I give up - all I get is
    "The following error occurred
    There was a problem uploading your file.
    Fog_Light_Relay_1.jpg"

    Here is the install directions for the fog lights:
    http://priuschat.com/attachments/priuschat_fog_lamp_install_prius_color-pdf.23488/
    The very last page has a schematic that a tech can use to see how they are wired.

    Step(s) 6.9, 6.10, 6.11 show where the relay should be mounted.
    Step 6.12 shows the inside of the fuse box & the red wire with the white connector BUT NOTE - the location where this wire connects is shown for a 2010.
    The paper instructions I have show the 2011 to use a connector at the top of the column just to the left of where the 2010 connector is plugged in at.

    I do see a problem with the way the relay is mounted - upsidedown! - seems they may have done this for ease of mounting, but the relay is only waterproof if hung with its mounting tab up.
    With the wire connections up, the relay will collect any water splashed onto the connections & pool into the plastic cup designed to protect the contacts.
    I do realize that water will not easily get into this area, but some can, & when it does, relay failure is to be expected.
     
    #12 kc410, Dec 1, 2014
    Last edited: Dec 1, 2014
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