1997 TJ Sport Fog Light Circuit

techjeeper

techjeeper

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We have spent a while today trying to trouble shoot the fog light circuit in our 97 TJ. We don’t have the factory relay/fuse box lid any more and relying on google hasn’t yielded much of a result yet. The interior switch appears to be working correctly. Head lights on, flip fog light switch, it lights up green. The wires that are coming out from under the fenders that appear to be factory and go to where the fog lights would be are dead. Light green wire and black wire. Both sides are the same. I’m a little lost as to where to go next since I have yet to find a diagram showing the relay in the under hood box.

I will have meter home tomorrow and can check whatever I need for power if I can get a little help in the right direction. I know the 97s can be a bit unique and screwy being a transition year and brand new model.

I think we will wire then in with these connectors for future times when the bumper needs to come off or something of that nature since the factory plugs are gone.
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I had the same issue on my 2000 and I found out that the fog light relays were supposed to be behind the glove box, they were not. I had the wires under the hood and if I recall the fog light signal was supposed to come thru a blue wire in the large connector up in the corner under the evap cannister. I also had the factory switch like yours. I spent a lot of time trying to figure it all out and I finally concluded that the relays and wiring was not complete from the factory and the vehicle never had fog lights. Once I figured that out I went to the wiring diagrams and ran new wiring with a relay on the firewall which I triggered with the wire that goes to the high beam indicator since I wanted mine for driving lights, so now they work anytime the high beams are on as long as the dash switch is also switched on.

The factory circuit uses 2 relays because one relay prevents the fog lights from working if the high beams are on. Look in the resource section for your wiring diagrams (if you don't have relays behind the glove box) and you will see which wires you need to tap behind the switch to trigger your relay and which wire goes to the high beam indicator if you want to use that like I did. I did not want to have to be fumbling for the dash switch all the time, the high beam operation works great. If you want tomorrow I will look for my drawings.
 
Looking at the 1998 underhood PDC you can see that there are no fog lamp relays in the PDC. Since my 2000 is the same I'm betting your 1997 will be no different.

98 PDC.jpg
 
B1Toad said:
I had the same issue on my 2000 and I found out that the fog light relays were supposed to be behind the glove box, they were not. I had the wires under the hood and if I recall the fog light signal was supposed to come thru a blue wire in the large connector up in the corner under the evap cannister. I also had the factory switch like yours. I spent a lot of time trying to figure it all out and I finally concluded that the relays and wiring was not complete from the factory and the vehicle never had fog lights. Once I figured that out I went to the wiring diagrams and ran new wiring with a relay on the firewall which I triggered with the wire that goes to the high beam indicator since I wanted mine for driving lights, so now they work anytime the high beams are on as long as the dash switch is also switched on.

The factory circuit uses 2 relays because one relay prevents the fog lights from working if the high beams are on. Look in the resource section for your wiring diagrams (if you don't have relays behind the glove box) and you will see which wires you need to tap behind the switch to trigger your relay and which wire goes to the high beam indicator if you want to use that like I did. I did not want to have to be fumbling for the dash switch all the time, the high beam operation works great. If you want tomorrow I will look for my drawings.
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I hadn’t looked behind the glove box but I see 3 relays. 1 that looks like a RY438 and 2 smaller ones.

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Here's the thread on how I did mine, notice I was on the wrong track till post #13 as I kept trying to get something in the under hood PDC to work which is wrong for 97-99 and some 2000s, it'll never happen:

https://wranglertjforum.com/threads...stalling-factory-fog-lights-on-2000-tj.68136/

and here's an article describing the relays behind the glove box and how 97-99 and some 2000s are different than later models which use relays in the PDC (note this article does not explain how to make your fog lights work, it is only a mod to allow them to work with the high beams on):


https://www.getahelmet.com/jeeps/tech/fogrelay/
 
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Also look at post #9 in my install link at the second and third pics, the light blue wire in that connector is the one that carries the fog light power to the under hood connectors, mine was not complete from the factory, it was only present on one side of the connector.
 
B1Toad said:
Also look at post #9 in my install link at the second and third pics, the light blue wire in that connector is the one that carries the fog light power to the under hood connectors, mine was not complete from the factory, it was only present on one side of the connector.
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Mine has the 2 relay harness behind the glove box, I’m going to start with checking those. Since one relay activates the other one, I think the first one is good and second is not working. I have yet to find anywhere with this diagram from the get a helmet Article, thank you for finding that. Still have found part numbers for the relays so I’ll pull them today and head to the parts store.

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B1Toad said:
Here's the thread on how I did mine, notice I was on the wrong track till post #13 as I kept trying to get something in the under hood PDC to work which is wrong for 97-99 and some 2000s, it'll never happen:

https://wranglertjforum.com/threads...stalling-factory-fog-lights-on-2000-tj.68136/

and here's an article describing the relays behind the glove box and how 97-99 and some 2000s are different than later models which use relays in the PDC (note this article does not explain how to make your fog lights work, it is only a mod to allow them to work with the high beams on):


https://www.getahelmet.com/jeeps/tech/fogrelay/
Click to expand...

Here’s the little 2 relay pig tail off the main harness. Sorry the pic sucks. I kept searching last night after this post and even this morning to find similar posts and found one similar to mine with the 2 relay harness and no power going to it.

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The way the relays work is relay #2 is normally closed and completes the ground to relay #1 which operates the lights from the switch br/wht wire, but when the high beans are switched on this opens relay #2 which cuts the ground to relay #1 disabling it. Check for power at the switch dark green/yel wire first, if there is power next turn switch on and there should be power on the br/wht wire which goes to relay #1

See diagram in next post
 
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Also, even though the relays for the fog lamps are not in the PDC, the fuse is in the PDC. Fuse #19 on mine.

edit: looking at the 1998 diagram (which appears to be the earliest we have in the resources) the fuse is #3 in the fuse block so be sure to look at that.
1998 fog dia.jpg
 
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B1Toad said:
Also, even though the relays for the fog lamps are not in the PDC, the fuse is in the PDC. Fuse #19 on mine.
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Mine shows here in the glove box fuse panel. I’m telling you 97 is a different animal. Some 97s even have old style YJ connectors on all the engine sensors and the 98s have the newer style. I swapped a 97 4.0L into my old 98 about 8-9 years ago and the sensor locations were all correct but not a single one had the right connectors. I had to steal all the sensors off the 98 4.0L and move them over which was a bummer because the new engine only had 40k miles on it and everything was in way better shape.

99 was a transition year too. Early built 99s are like 98s and later built are like 2000s. I think it was like 03 before they fully pulled their heads out of their butts and actually had continuity across them through 06.

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techjeeper said:
Mine shows here in the glove box fuse panel. I’m telling you 97 is a different animal. Some 97s even have old style YJ connectors on all the engine sensors and the 98s have the newer style. I swapped a 97 4.0L into my old 98 about 8-9 years ago and the sensor locations were all correct but not a single one had the right connectors. I had to steal all the sensors off the 98 4.0L and move them over which was a bummer because the new engine only had 40k miles on it and everything was in way better shape.

99 was a transition year too. Early built 99s are like 98s and later built are like 2000s. I think it was like 03 before they fully pulled their heads out of their butts and actually had continuity across them through 06.

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Yes you're right, I looked at the 98 diagrams and edited my post to say look at fuse 3 in the fuse block
 
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B1Toad said:
The way the relays work is relay #2 is normally closed and completes the ground to relay #1 which operates the lights from the switch br/wht wire, but when the high beans are switched on this opens relay #2 which cuts the ground to relay #1 disabling it. Check for power at the switch dark green/yel wire first, if there is power next turn switch on and there should be power on the br/wht wire which goes to relay #1

See diagram in next post
Click to expand...

This is a big help thank you.
 
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Actually disregard my suggestions to test for power at the switch, the fact that the indicator lights up when you switch it on proves that you have power on both the dk grn/yel and br/wht wires so no need to tear into that.
 
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Fog light circuit is up and running and new lights wired in. The relays behind the glove box were the problem. I went ahead replaced both since they were showing corrosion. 14YO did all the wiring.

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Might be a silly question but did you connect black with black and blue with red from your auxiliary lights to the existing wiring?
 
orourkcd said:
This might be a silly question, but did you align the red and black auxiliary light wires with blue and black, respectively?
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The black wires from the jeep at the fog light locations are the grounds and were connected the black wires on the lights. Blue is power and wired to the red on the lights.
 
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