HELP What else? How to wire foglights

[YetiX]

Sort of a different twist on an old question.

I got stock fogs at a junkyard. They have the harness that goes from the lights back through the firewall and ends in three wires. There's no relay in any of this wiring and no way to connect it to the stock switch.

My questions:

1. Can I hook up the positive directly to the battery?

2. How do I wire a relay into the three wires coming through the firewall?

3. How do I connect the stock switch so that it lights up and controls the switch?

4. I'd like to be able to turn the fogs on at any time, i.e. not connected to the headlight switch. How?

Sorry I've got so many questions and thanks for the help.

 

[YetiX]

Matt, any help?

I think I've answered some of my questions. As I understand it I can draw power straight from the battery and I got a diagram for my relay.

My only question now is how is the stock switch wired? It looks like there are four wires coming out of it and everything I've seen talks about three wires max. What are the four wires for?

Thanks,

 

[mattadams]

Hmm... is your stock switch a combination headlight/foglight switch or is it two seperate switches? I'm not sure what 4 wires would be for because I haven't messed with stock switches too much. Best bet would be to forget the stock switch altogether and go with an aftermarket switch . Your stock fog light switch would be wired up so it would only come on with headlights, and not when your hi-beam is on.

 

[YetiX]

Matt, thanks for answering.

The stock switch sits in the radio console right below the switch for the rear defroster. It's a seperate switch which controls just the foglights. Currently the switch aint wired to anything. I'd like to use the stock switch to maintain the stock look not to mention the fact that the switch doesn't currently light up at night which looks lame.

Any idea what the extra wire is for? (i.e. most fog light switches have three wires.)

BTW, I can harness the fogs directly to the battery right?

 

[mattadams]

sorry this took so long to find... I honestly have no idea what that fourth wire would be to, unless the switch has the light the fades with the interior light? If thats the case that fourth wire could be the fade wire.

 

[YetiX]

Hey Matt, you're right!

I found out that the fourth wire is indeed for the interior lighting (i.e. dimming). When I hooked the switch up this weekend, the fog lights came on briefly then went out.

There are two fuses in my harness, a 15 amp wired on the positive power source wire and a 5 amp fuse wired into the wire between the switch and the relay. The 5 amp fuse had blown, causing the lights to go out.

I then wired a fog light switch from an old set of Hellas and now they work fine.

Does this mean the stock switch is bad? Or is it just that the stock switch has a higher load than 5 amps and I should remove the 5 amp fuse? Is there any way to test whether the stock switch is still any good?

 

[mattadams]

well you never want to put in a higher wattage fuse then whats in there originally, it could cause more problems then it can fix. I'm not sure but it sounds like you could have overloaded the switch. How did you wire your fogs up? Using a relay and connecting the hot wire from the relay to the switch wire of your stock switch, or just splicing all the wires in to your stock switch?

 

[YetiX]

If I recall correctly, three wires come through the fire-wall: red, tan and black. They connect to the relay at the appropriate points. There is a wire to the headlight switch (I wired the lights so they turn on with the ignition) and then the switch is wired to the relay. I used the diagram in the Haynes manual and with the Hella switch everything works fine.

I used the same wires to wire in the stock switch as I am with the Hella switch (I hadn't hooked up the dimmer wire yet) and the 5 amp fuse blew. I can't recall if the diagram in the manual called for an in-line fuse at that point or not. If it did not, can I get rid of the fuse altogether?

More importantly, is there any way to find out if the switch even works?

Thanks,

 

[mattadams]

ok here's what I would do. Start over. LOL Take your wires and uninstall them all over (this is because I hate troubleshooting step by step).
Here's what you do.
You mount your relay somewhere. You hook up the wires that go to the lights and ground wires appropriately. You hook up the wires from the relay for power that go to the battery (don't draw power for your lights to the relay from anywhere BUT the battery). You run one (count it ONE) wire through the firewall. This wire will be the hot wire that is coming off the relay. This may also be called the "switch" wire. Depending on how your wiring harness is set up, your switch may have two or three wires going from the switch to the relay, you do not need these. You need one. That one hot wire run in through the firewall and bring up to your switch. Splice it into the wire that goes out to your fog lights (if you can figure which one that is)
If you pick the wrong wire, you'll blow a fuse. Don't worry about it, thats what the fuse is there for. Put in a new 5-amp fuse and re-splice to a different wire until you find the right one. It automatically won't be the black one, black is ground

 

[YetiX]

Ok, I'll try that this weekend.

What do I do with the other three wires coming out of the switch? (I'm going to splice the dimmer wire into the dimmer wire for the rear defroster switch.) Do I need to ground the switch too? (I could simply splice the switch ground into the defroster switch ground also)

If I'm just running one wire from the switch to the relay, should that wire have a fuse in it? (That's currently where the 5 amp fuse is.) Or is the 15 amp fuse that's on the power wire sufficient?

Sorry for all the questions and I appreciate the help!

 

[mattadams]

your just using the stock switch right? Is the stock switch already all wired or does it just have the connectors? I was under the impression that the switch was already wired and everything, I don't have a similiar explorer set up to look at.
If that's the case then yes you would need to do some extra wiring on the switch. Whatever the ground connection is on the switch just ground to any part of the frame or body you can find (after grinding or scratching away as much paint as you can). The illuminator switch yes you splice into another illuminator. The only thing is I'm not sure what to do with the other two.
You may actually need to switch it if this is the case. That means have the wire coming in from the relay to the switch as your "switch" wire, then having power coming to the switch from the cigarette lighter or something like that.

I thought that the switch was all pre-wired, just didn't have the lamps hooked up to them. That's a little different .

 

[YetiX]

The stock switch is not currently hooked up to anything. (Just sits there and fills a hole in my dash!) It has four wires coming out of the back (actually there's a harness which plugs into the back which has four wires coming out of it). The wires are red/black (dimmer), black (ground), and two others which are tan/orange and blue/white. I'm not positive about the colors of those last two. In the diagram in the Haynes manual one is wired to the relay and the other is spliced into the headlight switch wire for the low beams. (I wired mine to a different wire so they could come on at any time.)

The Hella switch is currently wired in the same way, i.e. ground to ground, one wire to the relay and one wire to the headlight switch. Everything works perfectly.

The only thing I can think of is that the sock switch is bad but I don't know how to test that.

 

[Bill Kemp]

Does this help any?
Dead Link Removed

 

[YetiX]

Thanks Bill! That's exactly how mine is currently wired except that the fuse between the switch and the headlight switch is a 5 amp fuse.

If that fuse blows when I use the stock switch but not when I use the Hella switch, does that mean that the stock switch is bad?

Would one switch draw (or impede) more current than another and thus require a larger fuse?

Oh, and do the switch, relay and lights need to be grounded seperately or can they be commonly grounded?

Thanks,

 

[Bill Kemp]

You can ground them all together. Just uses more wire but its cheap enough.
You would need an elect. test meter with an ohm setting to test the switch or a lot of fuses.
I had no luck making the stock switch work with any of my lights. Only thing it does is light up w/the dash lights.
If your blowing fuses w/the stock switch it is wired incorrectly and I dont know what would be correct.
You could probably find out w/a ohm meter but I just used the PIAA switch instead. Got pissed...after the second switch crapped out.
One switch would not draw any more than the other but one (the factory one) may not be able to take the amount of current the other(hella) switch can. Which may cause it to short out and blow the fuse. That last part is just a guess.

 

[YetiX]

Thanks Bill. Since I have the stock fog lights I'd think the stock switch could handle the load. Well I'll mess with it this weekend and let y'all know how it goes.

Thanks for all of the info.