Upgrading fog light harness

HQuakers · Jul 27, 2009

I did a search but only came up with stuff pertaining to the H4 headlight harness. I have stock fogs on my 98 XJ that I am going to upgrade to something with more power (>55W). Since I am upgrading all the wiring, I figured I should do these as well, especially with all the bad things I hear about the stock wiring on the fogs. My question is does anyone make a pre-made kit for the fogs? I found this on eBay (meant for HIDs on stock wiring): http://cgi.ebay.com/ebaymotors/Harn...Q5fTruckQ5fPartsQ5fAccessories#ht_1651wt_1195

I think that will do the trick, but I'm a little concerned about the 14 AWG wire and the 30A relay as I think I want 10 or 12 AWG and a 40A relay. If there's no good premade kit, does anyone have any instructions on how to upgrade the stock fog wiring?

Thanks

Tim_MN · Jul 27, 2009

Usually when you buy fog lamps you get some wires, a switch and a relay. No special wire harness or other stuff. You don't need anything complicated for fog lamps.

Use the stock fog lamp switch and wires to control a standard automotive relay in the engine compartment. Use the relay output to power the fog lamps.

HQuakers · Jul 28, 2009

Tim_MN said:
Usually when you buy fog lamps you get some wires, a switch and a relay. No special wire harness or other stuff. You don't need anything complicated for fog lamps.

Use the stock fog lamp switch and wires to control a standard automotive relay in the engine compartment. Use the relay output to power the fog lamps.

Really? So I should be ok with the wires from the switch to the (new) relay? Should I run the power to these directly from the battery through the relay then? Sorry for the newb questions, but I don't want to cheap out on anything if I can help it.

Matthew Currie · Jul 28, 2009

HQuakers said:
Really? So I should be ok with the wires from the switch to the (new) relay? Should I run the power to these directly from the battery through the relay then? Sorry for the newb questions, but I don't want to cheap out on anything if I can help it.

Yes, that's basically all you need to do. Use the existing wiring, switch, etc. to actuate the relay, and run the power for the lights from the battery (don't forget to put in an appropriate fuse). This has the double advantage that you need not modify much, and also the fog lights will behave as they should, going off with high beam.

HQuakers · Jul 29, 2009

Matthew Currie said:
Yes, that's basically all you need to do. Use the existing wiring, switch, etc. to actuate the relay, and run the power for the lights from the battery (don't forget to put in an appropriate fuse). This has the double advantage that you need not modify much, and also the fog lights will behave as they should, going off with high beam.

Just what I wanted to hear, thanks. I did want to keep everything legal as well, so this is good news. Much easier than running all new wires into the cabin, etc.

HQuakers · Jul 31, 2009

Can anyone confirm this wiring diagram will work i.e. won't run the full load through the switch?

http://www.jeepforum.com/forum/showthread.php?t=653022

HQuakers · Aug 1, 2009

Saudade · Aug 1, 2009

Your diagram is a bit confusing. The center pin is 87A and is normally closed. The way you have it would have the pass side light on when the switch is off. Both lights should be hooked to pin 87 (normally open) so when you flip the switch, the relay energizes and connects 30 to 87 and both lights go on.

Begster · Aug 1, 2009

Saudade said:
Your diagram is a bit confusing. The center pin is 87A and is normally closed. The way you have it would have the pass side light on when the switch is off. Both lights should be hooked to pin 87 (normally open) so when you flip the switch, the relay energizes and connects 30 to 87 and both lights go on.

Not if he was using a DPST relay, which most light harnesses come with. These relays have no NC position, but turn on both 87 and 87a when activated.

Saudade · Aug 1, 2009

Ah, I overlooked that on the drawing.

HQuakers · Aug 2, 2009

Begster said:
Not if he was using a DPST relay, which most light harnesses come with. These relays have no NC position, but turn on both 87 and 87a when activated.

Saudade said:
Ah, I overlooked that on the drawing.

Thanks for the help. I will probably use the relay that comes with the PIAA lights. I will do some more research to make sure I don't mess it up...I just want to make sure the fogs can only come on with lows/parking lights and that the full load isn't going through the switch.

Saudade · Aug 2, 2009

Just hook the 12v source to the low beam circuit. When you switch to High beams, the fogs go out.

HQuakers · Aug 3, 2009

Saudade said:
Just hook the 12v source to the low beam circuit. When you switch to High beams, the fogs go out.

Will do, thanks.

Matthew Currie · Aug 3, 2009

HQuakers said:
Will do, thanks.

If you use the original switch and wiring to control the relay that job is already done, and you can give the 12 volt source a circuit of its own.

HQuakers · Aug 4, 2009

Matthew Currie said:
If you use the original switch and wiring to control the relay that job is already done, and you can give the 12 volt source a circuit of its own.

Yeah, that's what I'm planning to do...just wanted to make sure I got everything squared away beforehand...nothing worse than getting knee-deep into a project to realize you don't have what you need or you were completely wrong, heh. Thanks.

Upgrading fog light harness

HQuakers

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Tim_MN

Freakish Hand Strength

HQuakers

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Matthew Currie

NAXJA Member #760

HQuakers

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HQuakers

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HQuakers

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Saudade

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Begster

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Saudade

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HQuakers

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Saudade

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HQuakers

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Matthew Currie

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HQuakers

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