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Fog Light Mod

141K views 202 replies 93 participants last post by  TGladden82 
#1 ·
I want to turn my fog lights on without turning on my main headlights to do so....How do I go about doing this?

Thanks for the help.
 
#2 ·
Originally posted by mymazda62003@Oct 6 2004, 04:25 PM
I want to turn my fog lights on without turning on my main headlights to do so....How do I go about doing this? 

Thanks for the help.
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I thought about this as well...it would be nice if you could turn the fog lights on with the hadlight switch set for parking lights instead of all the way on. I *may* do some investigation to see if this can be done without tearing open the steering column...when I have time.

If I do, I'll reply to you in this thread.

Drew
 
#5 ·
You just buy seperate fog lights like I did and hook them up seperatly




Well honestly I have a to turn them on separate with the button the fogs came with. I hooked them up straight to the battery. I do wwhat you want to do. But i have to turn on my parking lights then turn on the fogs. It would be nice just to turn the switch over and have it turn on parkings and fogs.
 
#6 ·
Im dont know if this would mess up the lighting system or make them not be as bright but couldnt you cut the wires from the fogs and re-attach them to the wires that go to the yellow side markers? (Im pretty sure those turn on with the parking lights) Wouldnt that work? I could be wrong and if I am, Im sure plennty of people will let me know but it makes sense to me.
 
#7 ·
Originally posted by clay@Oct 6 2004, 10:34 PM
Im dont know if this would mess up the lighting system or make them not be as bright but couldnt you cut the wires from the fogs and re-attach them to the wires that go to the yellow side markers? (Im pretty sure those turn on with the parking lights) Wouldnt that work?  I could be wrong and if I am, Im sure plennty of people will let me know but it makes sense to me.
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Yes...it would be even easier to wire them to the parking lights which are nearby.

However, this creates a different problem. With this setup, you wouldn't be able to turn the fogs *off* with the headlights on. I wouldn't want that, either...I'd want them still switchable with the normalf fog light switch, but then come on when the headlights are set to park and not just full on. This would make the most sense to me.

Drew
 
#9 ·
I really don't understand why mazda makes you turn on your headlights to get the fog lights to work. I think the purpose of fog lights is that when you are in a foggy situation, regular headlights just reflect off the fog and make it impossible to see. Fog lights are angled lower and cut through the fog...but if the headlights must be on to get the fogs to work....in a foggy situation with the head lights and fog lights on wouldn't the head lights still reflect of the fog and make it tough to see?

does that make sense?
 
#10 ·
To have the fogs on independant of the main lights you will need to do several things.
1: get a manual showing the complete wiring harness.
2: find the hot wire that comes from the fog switch where it connects to the fuse box and cut it.
3: extend this wire through the firewall allong an existing loom
4: install a relay in an inconspicous location under the hood so that the hot wire from the fog switch turns on power to the fog lights. to do this, run an all hot lead to the relay and a lead to the fog hot, with the switch lead being the hot from the switch. DO NOT forget to ground this system.

The reason for running it all in the engine comparpment is to keep from having a 30 amp hot in the passenger comparpment, remember that the "fire wall" is named that for a reason......

relays can be bought from most nappa stores, just ask for an accessory/wiper relay, should be between $8 and $15

This is how I did it on my GMC truck, I had an additional relay that kept the low beams on when the high beams came on, but thankfully Mazda has done this for us.

This is also the propper way to run aftermarket fog lights.

glgst
 
#11 ·
Originally posted by grahamb@Oct 10 2004, 02:38 PM
I really don't understand why mazda makes you turn on your headlights to get the fog lights to work.  I think the purpose of fog lights is that when you are in a foggy situation, regular headlights just reflect off the fog and make it impossible to see.  Fog lights are angled lower and cut through the fog...but if the headlights must be on to get the fogs to work....in a foggy situation with the head lights and fog lights on wouldn't the head lights still reflect of the fog and make it tough to see?

does that make sense?
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you have it half right. The mazda fog lights are white which are really just more for looks the most effective lighting color in fog is actually yellow.
 
#12 ·
Hey everyone,

I got a hold of the wiring diagrams, and came up with a solution. :D

To give some background, this modification disconnects the control of the fog light relay from the headlight relay's switch, and instead connects it to the relay that controls the taillights, parking lights, side markers, and license plate lights. This way, the auto-off feature will still work, and you won't get caught leaving the fog lights on. The fog lights will now be controllable when only the parking lights are on.

Also, you should be aware of a few known issues:

This mod ONLY WORKS FOR V6 MODELS WITH INTEGRATED FOG LAMPS (sport package). There are instructions for the currently-known alternate configurations as follows:

If you have a non-sport model with lower fogs, look for instructions in this thread left by Skibum, which he's currently...the fog lamp relay is in a different place, so the procedure is slightly different. Unfortunately, Skibum found this out the hard way, so we want to make sure no one else has to go through what he did.

If you have a 4-cylinder model, read this post and this thread for instructions on what should be done differently.

If you have a Canadian model with daytime running lights, there's more to this mod. You can read the correspondence between myself and Spidey (start here) to make this additional change.

And finally, just so everyone's aware, you're technically not allowed to operate more than 2 pairs of headlights at a time. The stock Mazda6 takes care of this by turning off the fog lights when the high beams are on. After performing this modification, it will no longer work this way, so be careful to turn the fogs off whenever you're using the high beams, or be aware that you're not completely street legal.


Ok, now here's my handy-dandy picture. I only took one after I finished the job, but I circled and color-coded everything of interest, so it should be sufficient. Like I said, my mod was for a 6-cyl, American-spec. car with integrated fogs, any differences for your car should be discussed above.

[attachmentid=764]

Here are the steps involved:

1. Disconnect the negative battery cable. This time it's for real!

2. Disconnect the 2 nuts I've circled in cyan, and remove the 2 terminals from their studs.

3. Detach the wiring harness on the left from the fuse panel. I circled in yellow where it's attached. It can be jiggled free from there. Don't bother disconnecting the connector...that won't help. It's the wires underneath this harness that are holding the panel in the box.

4. Loosen the 4 clips circled in green and lift the fuse panel free of the box. I also had to cut some tape near where I've indicated in orange (edit: I marked the orange area to the left of where I should have...the tape is where the bundle of wires comes in just beneath the main fuse between those two terminals you removed) in order to lift it completly. Once you take these steps, there will still be a whole bunch of wires holding the fuse panel down, but it should now be free enough to do what we need.

5. You need to locate the wire that energizes the fog light relay's coil. This is the terminal indicated as white on the fog light relay, which is indicated as red in my picture. Locate this wire underneath the fuse panel. It was a solid pale green color in my car...I assume it will be the same for yours.

6. Once you locate the proper wire, follow it as far from the relay as you can, and cut it. You need to keep enough length to complete the modification. The wire should eventually lead back into the panel to another relay, but I couldn't trace it that far...it was stuck in a bundle with piece of tape, but I still had enough length. Tape the free end closed, because it will still be energized whenever your headlights are on and high-beams are off.

7. Route this wire over to the top of the panel to the taillight relay indicated in blue. The 'white' terminal is where it needs to go. You can see the wire in my picture if you look closely. I just stripped the end and stuffed it in the appropriate socket before re-inserting the relay.

8. Reassemble everything in the reverse order...you're done. Now test the modification.

One more thing...don't go thinking you can just run a wire between these two relays in order to avoid disconnecting the panel. If you don't cut the existing wire, you will create a short whenever you turn on the high-beams.

And feel free to ask questions...don't go cutting wires if you're unsure about something.

Drew
 

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#14 ·
Originally posted by drew@Oct 11 2004, 08:14 PM
Hey everyone,

I got a hold of the wiring diagrams, and came up with a solution. :D

To give some background, this modification disconnects the control of the fog light relay from the headlight relay's switch, and instead connects it to the relay that controls the taillights, parking lights, side markers, and license plate lights.  This way, the auto-off feature will still work, and you won't get caught leaving the fog lights on.  The fog lights will now be controllable when only the parking lights are on.

Also, you should be aware of two things:

1.  This mod ONLY WORKS FOR V6 MODELS.  If you have a 4-banger, let me know, and I can explain what you need to do differently.

2.  DISCLAIMER!!!  In Virginia, at least, you're technically not allowed to operate more than 2 pairs of headlights at a time.  The stock Mazda6 takes care of this by turning off the fog lights when the high beams are on.  After performing this modification, it will no longer work this way, so be careful to turn the fogs off whenever you're using the high beams, or be aware that you're not completely street legal.

Ok, now here's my handy-dandy picture.  I only took one after I finished the job, but I circled and color-coded everything of interest, so it should be sufficient.

[attachmentid=595]

Here are the steps involved:

1.  Disconnect the negative battery cable.  This time it's for real!

2.  Disconnect the 2 nuts I've circled in cyan, and remove the 2 terminals from their studs.

3.  Detach the wiring harness on the left from the fuse panel.  I circled in yellow where it's attached.  It can be jiggled free from there.  Don't bother disconnecting the connector...that won't help.  It's the wires underneath this harness that are holding the panel in the box.

4.  Loosen the 4 clips circled in green and lift the fuse panel free of the box.  I also had to cut some tape where I've indicated in orange in order to lift it completly.  Once you take these steps, there will still be a whole bunch of wires pulling down on the fuse panel, but it should now be free enough to do what we need.

5.  You need to locate the wire that energizes the fog light relay's coil.  This is the terminal indicated as white on the fog light relay, which is indicated as red in my picture.  Locate this wire underneath the fuse panel.  It was a solid pale green color in my car...I assume it will be the same for yours.

6.  Once you locate the proper wire, follow it as far from the relay as you can, and cut it.  You need to keep enough length to complete the modification.  The wire should eventually lead back into the panel to another relay, but I couldn't trace it that far...it was stuck in a bundle with piece of tape, but I still had enough length.  Tape the free end closed, because it will still be energized whenever your headlights are on and high-beams are off.

7.  Route this wire over to the top of the panel to the taillight relay indicated in red.  The 'white' terminal is where it needs to go.  You can see the wire in my picture if you look closely.  I just stripped the end and stuffed it in the appropriate socket before re-inserting the relay.

8.  Reassemble everything in the reverse order...you're done.  Now test the modification.

One more thing...don't go thinking you can just run a wire between these two relays in order to avoid disconnecting the panel.  If you don't cut the existing wire, you will create a short whenever you turn on the high-beams.

And feel free to ask questions...don't go cutting wires if you're unsure about something.

Drew
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Cool! Thanks for the mod, been looking for that. One question though:


>7. Route this wire over to the top of the panel to the taillight relay indicated in >red. The 'white' terminal is where it needs to go. You can see the wire in my >picture if you look closely. I just stripped the end and stuffed it in the >appropriate socket before re-inserting the relay.

Don't you mean the tail light relay in BLUE? The reg is already your fog relay I thought...
 
#15 ·
Originally posted by Spidy@Oct 12 2004, 02:41 AM
Cool! Thanks for the mod, been looking for that. One question though:
>7.  Route this wire over to the top of the panel to the taillight relay indicated in >red.  The 'white' terminal is where it needs to go.  You can see the wire in my >picture if you look closely.  I just stripped the end and stuffed it in the >appropriate socket before re-inserting the relay.

Don't you mean the tail light relay in BLUE? The reg is already your fog relay I thought...
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D'oh, you're right, my mistake. I'll fix the original post, and thanks for catching that.

Drew
 
#16 ·
Originally posted by drew@Oct 12 2004, 06:48 AM
D'oh, you're right, my mistake.  I'll fix the original post, and thanks for catching that.

Drew
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Excellent!

Thanks for figuring it out, with this mod my fogs will work EXACTLY the way I always wanted them to... and its such an easy mod!! :D Should work great for HIDS cause now I can use the fogs as daytime running lights up here in Canada eh!

Spidy
 
#17 ·
Originally posted by Spidy@Oct 12 2004, 03:41 AM
Excellent!

Thanks for figuring it out, with this mod my fogs will work EXACTLY the way I always wanted them to... and its such an easy mod!!  :D  Should work great for HIDS cause now I can use the fogs as daytime running lights up here in Canada eh!

Spidy
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What lights act as daytime running lights, now? What changes when you switch from 'park' to 'headlights on'?

There were some different diagrams for cars with daytime running lights. Although I didn't look at those specifically, I wouldn't expect anything to be different for this modification, but you never know.

If you do make this modification, post back here, so we can confirm it works for Canadians as well. :)
 
#18 ·
Originally posted by drew@Oct 12 2004, 07:56 AM
What lights act as daytime running lights, now?  What changes when you switch from 'park' to 'headlights on'?

There were some different diagrams for cars with daytime running lights.  Although I didn't look at those specifically, I wouldn't expect anything to be different for this modification, but you never know.

If you do make this modification, post back here, so we can confirm it works for Canadians as well. :)
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I suspect it shouldn't make a difference...

The DRL are just the regular low beams, but powered differently so they appear dimmer. I think the current is turned on/off really quickly so that it gives the appearance of being dimmer.

The way DRL work is when you start the engine, release the parking brake and you have your lights off, it turns on low beams (pulsating) and turns on the parking lights.

I can't remember what happens if you already have the parking lights on... I think (from memory), the parkign lights will stay on and the low beams will be pulsated.

I have disabled my daytime running lights because they're actually bad for HIDs...
 
#19 ·
Doh! It didn't work...

Hooked up everything as in the pic but it didn't work...

It actually behaved as usual... meaning the fogs came on when the low beams were turned on. But didn't come on with just the parking lights...

Oh well, at least nothing broke in the process. Gee, I guess it must have something to do with the DRL on canadian vechicles.
 
#20 ·
Originally posted by Spidy@Oct 13 2004, 02:21 AM
Doh! It didn't work...

Hooked up everything as in the pic but it didn't work...

It actually behaved as usual... meaning the fogs came on when the low beams were turned on. But didn't come on with just the parking lights...

Oh well, at least nothing broke in the process. Gee, I guess it must have something to do with the DRL on canadian vechicles.
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Yikes...that's not cool, because now you don't know what changed.

You do have a 6s, right? I'd change it back if I were you...sorry it didn't work.

Actually, do me (and yourself) a favor and look at the inside of the fuse box cover, and see if the 2 relays are labeled as they should be. The taillight relay is actually a 3-letter acronym called TNS or something like that, and the fog light relay should just say FOG LIGHT. The 6i has a fog light relay in a different place.

Drew


I think I found the problem...circled in red.

It looks like there's an additional component of the circuit for the fog lights. The auto off feature works differently when you're running DRLs, so there's an additional component directly controlling the fog lights. What you did so far is still good, I think, but you will need to do one more thing in order for it to work. It may or may not be worthwhile, because that location under the dash looks like it's hard to get to.

Anyway, if you look at the diagram, you can see that for the DRL-equipped models, two wires are connected to the auto-off device, but in other models, they are the same wire. I've added below the location of this auto-off unit, and the two pins on the connector where those 2 wires are located. If you're up to the challenge, it might be worth a try. No gaurantees, though, so if you feel like you want to cut your losses, I understand. Again, I'm really sorry it didn't work. I feel responsible.

[attachmentid=1752]

Drew
 

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#21 ·
Originally posted by drew@Oct 13 2004, 07:28 AM
Yikes...that's not cool, because now you don't know what changed.

You do have a 6s, right?  I'd change it back if I were you...sorry it didn't work.

Actually, do me (and yourself) a favor and look at the inside of the fuse box cover, and see if the 2 relays are labeled as they should be.  The taillight relay is actually a 3-letter acronym called TNS or something like that, and the fog light relay should just say FOG LIGHT.  The 6i has a fog light relay in a different place.

Drew
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We don't call it the 6s here in Canada, its just called a Mazda 6 GT V6... but equivalent to to the S probably.

The relays are exactly in the same place... that's why I thought it should work.

Its not called TNS though, it says "Tail Relay" and the fog one says "Fog Relay"

Do you have wiring diagrams for models with the DRL?
 
#22 ·
Originally posted by Spidy@Oct 13 2004, 04:03 AM
We don't call it the 6s here in Canada, its just called a Mazda 6 GT V6... but equivalent to to the S probably.

The relays are exactly in the same place... that's why I thought it should work.

Its not called TNS though, it says "Tail Relay" and the fog one says "Fog Relay"

Do you have wiring diagrams for models with the DRL?
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Look at my edit...I think I found the problem.

One more thing you can try as a sanity check would be to disconnect the wire you just moved, and see if the fog lights stop working all together. That should confirm that you did that part correctly.
 
#23 ·
Originally posted by drew@Oct 13 2004, 08:10 AM
Look at my edit...I think I found the problem.

One more thing you can try as a sanity check would be to disconnect the wire you just moved, and see if the fog lights stop working all together.  That should confirm that you did that part correctly.
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Yeah, when I was doing the mod that's the first thing I tried when it didn't work.
I just removed the wire and the fogs stopped working ... which is to be expected cause well, I cut the wire :)

Any way, don't feel bad! Its a community of volunteers here, not a dealership, lol!
 
#24 ·
Originally posted by Spidy@Oct 13 2004, 04:29 AM
Yeah, when I was doing the mod that's the first thing I tried when it didn't work.
I just removed the wire and the fogs stopped working ... which is to be expected cause well, I cut the wire :)

Any way, don't feel bad! Its a community of volunteers here, not a dealership, lol!
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If you can't get to that auto-off box, one thing you can do is cut the other wire that goes to the fog light relay coil, and ground it to the chassis (figure out which of those two studs on the fuse box is grounded). Then your fogs will always be on in the 'park' setting. I don't know if that's acceptable to you, but it's another option.

Here's another picture of the location of that module...From the 2 pictures, I don't think it's in the steering column, but furthur back under the dash.

The manual doesn't say anything has to be removed to access it, though, so you should be able to get to it from under the dash.

[attachmentid=1753]
 

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#25 ·
Hey.... guess what. Good news, houston we have lift off! :D

I made the additional modifications according to the wiring diagram you attached for the canadian DRL and it now works!

When I think about it, it makes sense b/c when the DRL are on, it doesn't let you turn on the fogs -- but the low beams are on. So, I guess there's an additional switch inside the DRL unit that disables forgs if the DRL are signalling the low beams to come on.

Fortunately I knew where the DRL unit was because I had to already snip a wire there to disable the unit for the HIDS , so it was no sweat!

So, thanks again drew. Works like a charm!

Only thing I don't like is that I had to push the wire into the socket where the tail light relay is. Would have been nice if I could have attached it to the wire underneath but I couldn't find which one it was... even by inspection.

Any thoughts on this area?

Not a big deal, but I guess I'm thinking several years down the road if the relay gets pulled out by someone (or even myself), they'll be thinking, what the heck, what's this wire for? Then they may leave it unplugged or just stick it back in the wrong hole...

Any ho, thanks again... my fogs now work great and I can use them for the DRL instead of the HIDS.
 
#26 ·
Awesome! I'm glad I could help you get it working.

Originally posted by Spidy@Oct 14 2004, 05:43 AM
Only thing I don't like is that I had to push the wire into the socket where the tail light relay is. Would have been nice if I could have attached it to the wire underneath but I couldn't find which one it was... even by inspection.

Any thoughts on this area?
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That same terminal is tied to the left side (as viewed from the front of the car) of the 2 fuses directly to the right of it...so the left terminal of the ILLUM and TAIL LIGHT fuses are the same 'node' in the electrical system. That may help you find which of those steel 'bars' underneath the panel belongs to the point that you're connecting to, because there is no wire...it's all part of the box. I didn't investigate that too much because the solution I had was 'good enough', as far as I was concerned. If you want, you could also tie it 'downstream' of one of those 2 fuses as well...it shouldn't draw too much power to create any problems. The ILLUM fuse probably carries the less load of the two.

If you can't find a wire to use from that description, any of the positive terminals of the parking lights, side markers...etc. can be used.

Drew
 
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