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Unread 08-08-2013, 02:17 PM   #1
facethenorth8
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1998 XJ Cherokee 
 
Join Date: Nov 2012
Location: Drexel Hill, PA
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upgrade headlight harness problem

Hi everyone..so I just put in the putco wiring harness and hella housings with hella bulbs. I was so excited that it all worked! Then...when I put on my high beams and then turned off the high beams, they stayed on along with the lows..had to turn headlights completely off to get the lows back on..any suggestions? Thanks!

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Unread 08-09-2013, 11:30 AM   #2
XJmike0122
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If you have factory fog lights try pulling the relay for them. Seems to work for sum guys.
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Unread 08-09-2013, 11:34 AM   #3
XJmike0122
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Never heard that happen with an IPF harness. Might be a get what you pay for type of thing.
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Unread 08-09-2013, 05:17 PM   #4
facethenorth8
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Well I pulled the relay for the fogs and now the headlights work....after further research, I found it has nothing to do with the brand of harness itself but with the wiring of the factory fogs...
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Unread 08-10-2013, 12:10 AM   #5
XJmike0122
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Quote:
Originally Posted by facethenorth8 View Post
Well I pulled the relay for the fogs and now the headlights work....after further research, I found it has nothing to do with the brand of harness itself but with the wiring of the factory fogs...
Your welcome. I'm glad that fixed the problem. I was not trying to be a dick or anything about the harness you bought. I have just never seen anyone ask that question after installing a IPF harness. Now knowing that was the problem did you find the mod to get the fogs to work or are you going to just run an aux switch to them?
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Unread 08-10-2013, 06:37 AM   #6
cruiser54
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Courtesy of EZEARL




Suppose to be the fix:
If you have stock fog lights on a 97+ and upgrade your harness in a manner that uses the factory wiring to trigger some new relays, your fog lights will have and/or cause issues unless you make some additional modifications to address the problem. It doesn't matter if you use a plug and play harness like the eautoworks or if you split your harness open and completely strip out all the extra factory wiring like I did. The factory fog circuit will cause your new lighting system to not work properly.

If you do nothing, your headlights will work as mentioned above. Low beams will be fine, but after you turn on your high beams, they will not turn off again until you completely turn off your headlights. Big issue here is that when you switch back to low beams, both the high beam and low beam filament will be remain powered causing your bulbs to endure 115W worth of heat output instead of the 55W or 60W that they are designed for. From what I've read this can cause them to overheat and burn out within minutes.

So what is happening? If you look at the driver's side headlight plug (and you have factory fogs) you will notice there are two red wires coming out of one of the terminals. One is a small 18g Red wire which sadly is the stock high beam wire. The other is an even smaller 20g Red wire which ties into Fog Lamp Relay #1 in the PDC. Please keep in mind that Fog Lamp Relay #1 is NOT used to provide battery power to the fog lights the way we commonly use them with aftermarket lighting. It is located before the switch and simply cuts power to the Fog Light Switch unless the Headlight Switch and Beam Selector Switch are in the proper positions. It does this as law dictates that you can't run your high beams and fogs at the same time. Though not a problem here in CA, I've read that states with safety inspection programs will fail your vehicle if the lights don't operate this way.

I dug into the wiring diagrams but had to have kastein help me decipher them because there was something about this circuit that just wasn't making much sense to me. I still don't understand the function of Fog Lamp Relay #1 in its entirety, but we're only concerned with the part that is affected by the headlight harness anyways. Essentially, when your Headlight Switch is off, the relay coil receives no power and therefore won't allow your fog lights to come on. When your Headlight Switch is turned on, one side of the relay's coil receives 12V which causes the relay to activate and send power through to your Fog Light Switch. When you turn your high beams on, 12V is sent out to your headlight socket via the Beam Selector Switch, and then is sent back to the other side of the relay coil via the skinny Red wire on that shared terminal. This brings both sides of the relay coil to 12V, thus causing it to deactivate and turn off the Fog Light Switch. Weird huh? The factory designed it so that the relay is off with both sides at 0V, on with one side at 12V, and then off again with both sides at 12V. While it makes perfect sense now, this is the part that was confusing me.

So what's the problem then? Well, it turns out that even when the high beams are off, there is still approximately 5V on that skinny Red trigger wire for some reason which I still don't understand. While this is obviously not a problem in the factory configuration, it becomes a problem when you are using the high beam wire (which is directly tied into the skinny Red wire) to trigger your aftermarket high beam relay. A typical automotive relay requires approximately 8V to activate and needs to drop to somewhere below 1-5V to deactivate. When you first turn on your lights there is no problem because the phantom 5V is not enough to activate your new high beam relay. When you turn your high beams on, your new relay gets 12V and kicks on. When you go to turn off your high beams, the phantom 5V keeps the new relay from deactivating and voilą, your high beams are stuck on...

So how do we fix this? There are a few common suggestions that are out there that I just wasn't happy with, and a few that sort of work, but not as required by law:

1. Don't use your high beams, new lights are bright enough anyways (OK...)
2. If you have to use your high beams, turn your headlights off briefly to get them turn off (PITA)
3. Pull various fuses (lose your fog lights)
4. Pull the fog lamp relay (again, lose your fog lights)
5. Modify the fog lamp relay (fog lights work, but won't cut out when your high beams are on?)
6. Install a jumper in place of the fog light relay (fog lights work, but switch is always hot?)

One post I saw got it right though. lilredxj99 mentioned it in another thread which I didn't find until after the fact. The details were a little fuzzy and I still thought the issue deserved some further explanation so that's why I just wrote this damn novel...

Oh yeah, so the right way to do it... Cut the 20g Red Fog Lamp Relay #1 ground/trigger wire at the back of the driver's side headlight plug. Extend this wire using your preferred method so that it is long enough to reach your new aftermarket high beam relay. Splice it into the 87 pin (output) of your new high beam relay. If you have two 87's (which is ideal), either one is OK. Do not however use 87a if your relay has it!

Yep, that's it... Your high beams will now turn off when they're supposed to, your fog lights will turn on/off when they're supposed to, and your low beams will continue to work as they're supposed to. Sure you could have skipped all the way down to the bottom and found your answer, but you wanted to know how/why it works, right?
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Originally Posted by chris87xj View Post
If you own a Renix Jeep, you'll want to check this out. >

An index to over 25 write-ups can be found in Post #1.

Cruiser's Mostly Renix Tips
Refresh*Connections*Before*Replacing*Components
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Unread 08-13-2013, 02:21 AM   #7
1997xj
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Awesome cruiser54!

Know if I can cut the red wire with the white stripe to the drl module so my high beams and dash indicator both work by any chance? Built the harness over the weekend and hope to put it in tomorrow
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Unread 08-13-2013, 05:08 AM   #8
cruiser54
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Quote:
Originally Posted by 1997xj View Post
Awesome cruiser54!

Know if I can cut the red wire with the white stripe to the drl module so my high beams and dash indicator both work by any chance? Built the harness over the weekend and hope to put it in tomorrow
That I don't know. Heck, I didn't know about the factory fog fix until EZEARL figured it out. LOL.
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Quote:
Originally Posted by chris87xj View Post
If you own a Renix Jeep, you'll want to check this out. >

An index to over 25 write-ups can be found in Post #1.

Cruiser's Mostly Renix Tips
Refresh*Connections*Before*Replacing*Components
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Unread 08-13-2013, 05:43 AM   #9
1997xj
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I've got those too so that's a big help. Thanks again
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