NAXJA Forums -::- North American XJ Association  

Go Back   NAXJA Forums -::- North American XJ Association > NAXJA Unibody Jeep Technical Forums > Jeep Cherokee XJ (1984 - 2001) > OEM Tech Discussion
HOME Member FAQ Sponsor Info Rules Bylaws E-Mail

OEM Tech Discussion Forum for OEM (Original Equipment) or stock XJs and MJs.

Reply
 
Thread Tools Display Modes
  #1  
Old January 12th, 2017, 12:16
4x4JeePmaNthINg's Avatar
4x4JeePmaNthINg 4x4JeePmaNthINg is offline
NAXJA Forum User
 
Join Date: Nov 2008
Location: colorado, Foco
Posts: 430
check factory fog light wiring

hey all, when i bought my jeep the factory fogs were toast and have since been removed. I know this might be a dumb question but do i test the leads on the remaining wires for 12v to make sure they are still getting power? im thinking of just buying the same factory style cheap fogs but i want to know it was just the lights that were bad before.

also do the headlights need to be on/off/ hibeam anything speacial to normally run these i never knew how they worked.

if not what am i looking for with a multimeter, im clearly in the dark here

thanks for the help
Reply With Quote
  #2  
Old January 12th, 2017, 13:20
CarbonXJ's Avatar
CarbonXJ CarbonXJ is offline
NAXJA Forum User
 
Join Date: Mar 2011
Location: columbia
Posts: 378
Re: check factory fog light wiring

My factory fogs work with the Jeep ignition off, but headlights on - I find that odd but it's how it's always been. Either way, have the headlights on low beam, stock switch on, and test the factory connectors for 12v power with a test light. That will tell you if you getting any power. If not, move up the line, checking the wiring, and then the relay in the PDC, then the fuses, etc. The factory fogs turn off with the high beams. The factory fogs are actually quite useful (properly taken care of) and put out a good beam spread (I added a harness for cleaner power).
Reply With Quote
  #3  
Old January 12th, 2017, 14:17
dan1977p's Avatar
dan1977p dan1977p is offline
NAXJA Member
 
Join Date: Oct 2015
Location: Virginia Beach, VA
Posts: 1,293
Re: check factory fog light wiring

Fog lights are only supposed to work with the low beams on. I'd test for voltage that way. Look for a fuse first.
__________________
91 Sport 4.0L, aw4, np231, 4.5" long arm, 33" BFG AT KO's - SOLD

SeXJ Build Thread
Reply With Quote
  #4  
Old January 20th, 2017, 14:01
4x4JeePmaNthINg's Avatar
4x4JeePmaNthINg 4x4JeePmaNthINg is offline
NAXJA Forum User
 
Join Date: Nov 2008
Location: colorado, Foco
Posts: 430
Re: check factory fog light wiring

ok i bought a test light. i cant seem to find a 99 xj pdc diagram that tells me what Fuses are for what, just the relays.

I turned on the head lights and grounded the test light to the battery. I checked the fog plugs with no luck, then i checked all the pdc fuses. There were two that did not light up. I replaced them and still they did not light up so i pulled the dash off and removed the fog switch. I am getting power to the switch, maybe its a bad switch. with the switch out i went back and tested the two fuses that didnt light up and the tester lights up with the switch removed.

Does this indicate a bad switch or possibly relay?
Reply With Quote
  #5  
Old January 20th, 2017, 14:06
4x4JeePmaNthINg's Avatar
4x4JeePmaNthINg 4x4JeePmaNthINg is offline
NAXJA Forum User
 
Join Date: Nov 2008
Location: colorado, Foco
Posts: 430
Re: check factory fog light wiring

also how do i test the switch?
Reply With Quote
  #6  
Old March 1st, 2017, 08:55
XJI6191's Avatar
XJI6191 XJI6191 is offline
NAXJA Forum User
 
Join Date: Mar 2013
Location: between London & South Devon, England
Posts: 40
Re: check factory fog light wiring

These switches can be a problem 'cos they over heat.

Probably the simplest test is to see if the green warning light comes on, idf it does but still nothing at the connectors, it's a wiring issue.

Next just bypass the switch. It can be overhauled, easily & successfully: there's a "how to" post on here somewhere.

PartsMonster is a good source of reasonably priced replacements - if it really comes to that.
Reply With Quote
  #7  
Old March 1st, 2017, 09:33
Greenspan's Avatar
Greenspan Greenspan is offline
NAXJA Member
 
Join Date: Aug 2016
Location: Los Angeles
Posts: 35
Re: check factory fog light wiring

Do you have a multimeter? To test the switch you just measure the resistance of the switch, when it's off it should be high resistance (megaohms) and when it's on it should be low resistance (milliohms). Also, most multimeters will have a connection tester that will beep if there is a connection (i.e. switch on).

If you don't have a multimeter, you can use the test light. If one terminal of switch is connected to 12V, the test light should turn on when touched to the other terminal of the switch.
Reply With Quote
  #8  
Old March 1st, 2017, 09:41
N8N_99xj N8N_99xj is offline
NAXJA Member
 
Join Date: Dec 2011
Location: Sterling, VA
Posts: 1,026
Re: check factory fog light wiring

Quote:
Originally Posted by dan1977p View Post
Fog lights are only supposed to work with the low beams on. I'd test for voltage that way. Look for a fuse first.
Low beams or parking lights. There is relay logic that keeps them off when the high beams are on.

Side note: if you are running a relay harness (or possibly LEDs), you need to put a relay in behind the driver's side headlight to un-ground the fog light relay coil when the high beams are on. That wire relies on the driver's side high beam filament to ground the fog light relay coil (that's how the fogs go off when you hit the brights) and if you're running a relay harness that may result in the high beams sticking on - it did for me.

If you're running LEDs it may cause the high beams to glow if the fogs are on.

Also, obviously, if your DS high beam is burned out fogs may not work. Not sure if it will then ground through the pass side high beam filament or not. Definitely fogs will not work if both high beams are burned out or if you don't have headlamps installed.

There are two relays related to the fog lights; if someone removed the factory fogs they may have removed those relays as well.
Reply With Quote
  #9  
Old March 1st, 2017, 12:03
4x4JeePmaNthINg's Avatar
4x4JeePmaNthINg 4x4JeePmaNthINg is offline
NAXJA Forum User
 
Join Date: Nov 2008
Location: colorado, Foco
Posts: 430
Re: check factory fog light wiring

Quote:
Originally Posted by Greenspan View Post
Do you have a multimeter? To test the switch you just measure the resistance of the switch, when it's off it should be high resistance (megaohms) and when it's on it should be low resistance (milliohms). Also, most multimeters will have a connection tester that will beep if there is a connection (i.e. switch on).

If you don't have a multimeter, you can use the test light. If one terminal of switch is connected to 12V, the test light should turn on when touched to the other terminal of the switch.
maybe a dumb question but can this still be done for power off if i unplug the switch?
Reply With Quote
  #10  
Old March 1st, 2017, 15:16
Greenspan's Avatar
Greenspan Greenspan is offline
NAXJA Member
 
Join Date: Aug 2016
Location: Los Angeles
Posts: 35
Re: check factory fog light wiring

Yes, but if it is disconnected you will need to connect one end of the switch to a 12v source with an alligator clip or something to use the voltmeter. The light should turn on if the switch is on, the light should be off if the switch is off. Using a multimeter the switch can be disconnected see an example here on Youtube: https://www.youtube.com/watch?v=lB-aULIjiog

Last edited by Greenspan; March 1st, 2017 at 15:22.
Reply With Quote
  #11  
Old March 1st, 2017, 18:46
Jeep Driver Jeep Driver is offline
NAXJA Forum User
 
Join Date: Jun 2016
Location: Parrottsville
Posts: 631
Re: check factory fog light wiring

Just my opinion-


Fog/driving/light bar...........should be wired independently with it's own harness just as with the headlight harness.

My bar is activated by the brights switch and I have an on/off switch on the dash........this is all done with relays.

Never have full current load through a dash switch........relay trigger only, neg preferred.
Reply With Quote
  #12  
Old March 1st, 2017, 23:01
4x4JeePmaNthINg's Avatar
4x4JeePmaNthINg 4x4JeePmaNthINg is offline
NAXJA Forum User
 
Join Date: Nov 2008
Location: colorado, Foco
Posts: 430
Re: check factory fog light wiring

Quote:
Originally Posted by Jeep Driver View Post
Just my opinion-


Fog/driving/light bar...........should be wired independently with it's own harness just as with the headlight harness.

My bar is activated by the brights switch and I have an on/off switch on the dash........this is all done with relays.

Never have full current load through a dash switch........relay trigger only, neg preferred.
agreed but i would like to use the factory switch. If i can wire this to run aux lights independently from the headlights im better off. I have a headlight harness (pulled factory fog relay for hi/low switchability) and will most likely have to add a new harness, but if i can also keep the stock mounted switch it sure would be nice.
Reply With Quote
  #13  
Old March 1st, 2017, 23:02
4x4JeePmaNthINg's Avatar
4x4JeePmaNthINg 4x4JeePmaNthINg is offline
NAXJA Forum User
 
Join Date: Nov 2008
Location: colorado, Foco
Posts: 430
Re: check factory fog light wiring

Quote:
Originally Posted by Greenspan View Post
Yes, but if it is disconnected you will need to connect one end of the switch to a 12v source with an alligator clip or something to use the voltmeter. The light should turn on if the switch is on, the light should be off if the switch is off. Using a multimeter the switch can be disconnected see an example here on Youtube: https://www.youtube.com/watch?v=lB-aULIjiog
switch is out, does it matter which end is clipped to 12v?
Reply With Quote
  #14  
Old March 2nd, 2017, 06:43
90xj06's Avatar
90xj06 90xj06 is offline
NAXJA Forum User
 
Join Date: Aug 2006
Location: Peabody, MA
Posts: 1,665
Re: check factory fog light wiring

i think it does if its a 3 wire. because of the light on the switch. id have to guess that if you had them swapped the indicator light would be stuck on.
Reply With Quote
  #15  
Old March 2nd, 2017, 22:30
Greenspan's Avatar
Greenspan Greenspan is offline
NAXJA Member
 
Join Date: Aug 2016
Location: Los Angeles
Posts: 35
Re: check factory fog light wiring

Found this on another forum:



http://www.cherokeetalk.com/forum/f8...-wiring-57745/

You can see how the switch is wired. When the switch is on connections between 3 and 2 should be shorted. So if you apply 12V to either 3 or 2, and turn the switch on, the voltage tester should detect voltage at the other terminal. It doesn't matter which one you apply 12v to, you should just detect voltage on the other one when the switch is closed.

Normally you'd use a multimeter continuity tester to test this, but this is a kinda roundabout way of testing it using a voltage tester.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Check Engine Light Wiring nosigma OEM Tech Discussion 4 April 8th, 2013 18:30
Factory fog light switch wiring help Blacked0utXJ Modified Tech Discussion 12 March 5th, 2012 16:02
Using Factory Fog Light Switch And Wiring M4Madness Modified Tech Discussion 3 January 14th, 2010 21:48
96 factory fog light wiring gba88 OEM Tech Discussion 3 November 7th, 2006 00:56
Factory Fog light wiring ??? evilpresence OEM Tech Discussion 5 January 17th, 2005 12:31


All times are GMT -7. The time now is 21:11.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
NAXJA and NAXJA logo's Copyright NAXJA. All content/images Copyright NAXJA 1999-2014