Parking Light Not Working?

Discussion in 'Electrical & Stereo' started by 5-oh-MUSTANG, Oct 23, 2014.

  1. 5-oh-MUSTANG

    5-oh-MUSTANG Well-Known Member

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    I thought my passesnger side parking bulb was out, but turns out it was fine, but replaced it anyways. The driver side parking light works fine but the passenger side does not. The hazzards work on both and so does both turn signals. The parking light just does not illuminate. I swapped the bulb socket with the driver side, and it still didnt work. This lead to me know that it was something to do with the wiring then. I also checked the headlight switch and it seems fine.. no melting or anything. Stumped about this. Any suggestions?
     
  2. mcglsr2

    mcglsr2 Well-Known Member SN95 Supporter

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    Sounds like there's an open circuit somewhere in the parking light wire - I don't know if this wire is shared by the turn signal wires. At some point, they must be the same wire since there's only the two going to bulb. I would suggest backtracking those wires until they split and you identify the wire specific to the parking light switch. My guess is open circuit at that point.
     
  3. ttocs

    ttocs Legend

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    ok so at this point we know the pass side bulb is new correct? you didn't replace it with a used bulb right?

    What just changed from above now for it to not work I thought it was a new bulb that was working?

    The driver side didn't work when you swapped it or the pass side?
     
  4. 5-oh-MUSTANG

    5-oh-MUSTANG Well-Known Member

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    Yes both bulbs are new and work perfect. I swapped both the bulbs and sockets on both sides, driver side works perfect in any case but same thing every time on passenger side, no bueno.
     
  5. 5-oh-MUSTANG

    5-oh-MUSTANG Well-Known Member

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    There are 3 wires going intro the socket, ground-minor-major. They all seem connected and fine...
     
  6. mcglsr2

    mcglsr2 Well-Known Member SN95 Supporter

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    I need to look at a wiring diagram. Also, there isn't anything wrong with the socket itself, is there? Sockets have gone bad before. Anything in the socket blocking some of the contacts, dirt or something? Do you have a digital voltometer, can you see if there is voltage coming in to the wire(s) where it connects to the bulb socket? If you are getting voltage there, but the bulb doesn't work, then it's the socket. If you have no voltage (with the parking lights turned on of course) at the wire(s) going into the socket, then the issue is further back...
     
  7. 5-oh-MUSTANG

    5-oh-MUSTANG Well-Known Member

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    Makes sense. I can check that out.
     
  8. 5-oh-MUSTANG

    5-oh-MUSTANG Well-Known Member

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    Just checked voltage in sockets with parking lights on. Driver side had around 6 and passenger side has 0-0.1. The wiring looks fine, but i still dont understand how the turn signal and hazards work perfect on both but parking light doesnt on one side :/
     
  9. mcglsr2

    mcglsr2 Well-Known Member SN95 Supporter

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    I'll check out the wiring diagram and get back to you soon.
     
  10. mcglsr2

    mcglsr2 Well-Known Member SN95 Supporter

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    Alright, here's the thing - and warning, this will be a lot of text, please take a minute to read it and digest as I think it will help you find your issue. I apologize for the wordiness but I wanted to make sure I was clear in my directions. (I added a picture at the end in case of the wall of text is just too much.) So onward...

    The parking bulbs are dual filament. Which is also why there are 3 wires going into the socket. 1 wire is ground, 1 wire feeds voltage for the parking light, the 3rd wire feeds voltage for the turn signal/hazards. When you have the parking lights on, one of the filaments in the bulb lights up. When you flip on the signal or hazards, the second filament is pulsed, giving the flash. Since the parking lamps and turn signal/hazards are feed from two different circuits, this is how you can get a situation where the turn signals work, but parking lights do not. I took a look at the wiring diagram, so here's what I've got:

    1) if you recently replaced the bulb, confirm that it is in fact a dual filament bulb. It should have two little spring-looking things inside of it (this is what gets hot and puts out the light), not one. Did the passenger bulb work on the driver side, for both parking lights and turn signal/hazard? If yes, then the bulb is good. If it didn't, or if it has only 1 filament, then you need a new bulb. I suspect your bulb is fine.

    2) Assuming the bulb is good, the fact that the driver side bulb does not work properly in the passenger side leads to me think the same thing as you in your first post - there is something wrong with the wiring. So, taking a closer look at the wiring:

    On your passenger side socket connector, there should be 3 wires present. The colors I will provide are based off a 95 Mustang wiring manual, so if you have different colors, please stop here and let me know. (Note: to measure at the connector, either stick your digital multimeter (DMM) probe into the back of the connector where the wire enters, or if it's too big, use a straightened out paper clip or equivalent and connect your probe to that.)
    • One wire will be black - this is the ground. To test this wire, use your DMM to measure the resistance between the wire at the connection and a good vehicle ground (or negative battery terminal if you can reach it). You should see 0 Ohms for your resistance. If you don't, let me know. Since your turn signal works, I expect this to not be an issue.
    • One wire will be Light Green with a White stripe - this is the + feed for the turn signal/hazard function. When you have the turn signal on, or hazards on, this wire will pulse +12v. Use your DMM to measure voltage here, you should see it pulsing something close to nothing, then close to 12v, then close to nothing, then 12v, etc. If you don't, let me know what you are seeing. You say that your turn signal works fine, so I expect this to not be an issue.
    • One wire will be Brown - this is the + feed for the parking lamps, and the likely culprit. With the parking lights on, measure the voltage at the connector with your DMM, you should see a solid +12v. If you do see a solid +12v here, then the issue is with the socket itself. If you do not see a solid +12v, then the issue is with the wiring. Let me know what you find here.

    Assuming, from the 3rd bullet, if you discover that there is no voltage at the wire, then there is an issue in the wiring itself. However, since your driver side works, that means that the issue is between the splice that feeds both passenger and driver lamps and the passenger socket itself. This part is going to be the b1tch part. To find the splice, start with the passenger side socket, and follow the Brown wire until it enters a harness. This harness should travel across the front of the car until it reaches close to where the battery is. From here it will split (what the factory manual calls a Take Out, or T/O), with some wires/harness continuing on to the other headlight/parking light, and the main trunk heading to the back of the car, parallel to the battery. It is at this split that I think the splice is located. Try to carefully unwrap the harness here, look for the Brown wire (but make sure it's the one heading to the passenger side, NOT the one heading to the driver side) and check again for voltage with the parking lights on. If you you do not see voltage, then move up the harness past the splice - move towards the back of the car, same Brown wire but AFTER it splits to go to the driver side lamps (meaning, check the voltage at the wire before it splits off to go to the different side lamps). Check voltage here - I fully expect you to have +12v here, as your driver side parking light works.

    If you DO have voltage here, then the issue is that the Brown wire is cut or nicked between the split and where it terminates at the socket connector. Either unwrap the harness, locate the cut/nick and repair it, or maybe even easier is to just splice in new wire, run it along the harness, and connect it at the connector. It's up to you. Just keep in mind that if the wire was cut/nicked, try to see if there was a reason for it - as in maybe something is hitting the harness, so you can prevent future cuts/nicks.

    If you DO NOT have voltage at the Brown wire BEFORE the splice, then either you are measuring voltage incorrectly/doing something wrong, OR I am wrong about the location of the splice. If you are thinking I am wrong about the location of the splice, here's what you can do. There is a black, 16 pin connector located near the battery (maybe under the tray?), that joins the headlight/lamp harness to the dash wiring. If you continue to follow the harness that the Brown wire is located in, you will eventually get to this connector. Look for the Brown wire (it's the only Brown wire going into this connector, located at Pin #4, which if you are looking at the female side of the connector, is located at the top left. Again check voltage here. You should, for 100% certain, get +12v here. If you DO NOT, you are doing something wrong. If you DO, then the issue is somewhere between this connector and the socket. Do NOT cut the wire here, as this wire feeds both the driver and passenger side. Work down towards the lights until you find the splice. Then do what I mentioned in the above paragraph.

    Good luck, let me know if I can do anything to assist!

    Edit: I made up a quick drawing which sort of summarizes what I am saying in words above (which you should still read).

    Measure at each location: 1, 2 and 3, then let me know what you find.

    [​IMG]
     
  11. 5-oh-MUSTANG

    5-oh-MUSTANG Well-Known Member

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    mcglsr2 thank you for the descriptive and detailed explanation. I have just checked for voltage at the socket wiring and got around 12v for hazards when flashing with the green wire and still had 0 for the brown wire when parking lights were on. So this means it has to be wiring. I could not check for any nicks in the brown wire as I strongly don't think it could of tore or anything because the harness is all wrapped up in looms and electrical tape from factory! It looks untouched, but i will still double check when I open it up. Also, i could not find the 16 pin connector you were talking about, but I did discover another problem. I traced back what looks like an aftermarket security system that is spliced into one harness, not sure which one, and travels back to under my dash to some sort of module. Anyways don't think that had anything to do with the light harness.
     
  12. mcglsr2

    mcglsr2 Well-Known Member SN95 Supporter

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    Sure thing. And not sure about the security system. I'll see if I can located that connector on my car and give you a better location. The book shows it being located right where the battery is, so I assumed it was under the tray or something. Not sure.

    If your driver side parking light works, then we know for a fact now, assuming there really is 0 voltage on the brown wire at the socket, that the issue is the wire between the splice and the socket. If the issue were further up, closer to the headlight switch, then you would have the same trouble on the driver side as well. But that works, so it must be between the splice and socket. I think what I would do is located the splice, confirm that there is voltage on the other side (Location #2 in the diagram), and then just add a new wire in there that goes to the socket, and not worry about the brown wire anymore. That would be the easiest. But it's up to you.
     
  13. ttocs

    ttocs Legend

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    just curious, have we checked the fuses?
     
  14. 5-oh-MUSTANG

    5-oh-MUSTANG Well-Known Member

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    lol no, but id assume there is only one fuse for both lights?..
     
  15. ttocs

    ttocs Legend

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    it should be but I always start on fuses myself, one less thing to worry about.

    And one other stupid thing to check, can you pull the bulb out flip it 180 degrees and then reinsert it? I assume your using a halogen and I don't think they are reversible normally but if its some weird led or if you knock one the clip off it might fit backwards.

    Otherwise as he shows trace that brown wire back to the switch or any connections.
     
  16. 5-oh-MUSTANG

    5-oh-MUSTANG Well-Known Member

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    f*** that wire man. Still dont get how it just stops working like that. The wire is unmolested.
     
  17. mcglsr2

    mcglsr2 Well-Known Member SN95 Supporter

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    Yah who knows, weirder stuff has happened. It could have been a bad solder at the factory, some corrosion got the wire, the electricity can't flow anymore, who knows. If you don't get any voltage at the connector, but do further up the brown wire before it splits to the driver side, what else could it be?
     
  18. 5-oh-MUSTANG

    5-oh-MUSTANG Well-Known Member

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    Maybe it can be a relay or something that connects to the brown wire
     
  19. mcglsr2

    mcglsr2 Well-Known Member SN95 Supporter

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    I'm not sure how it can be. The way the wiring diagram shows it working is like this:

    Battery (hot at all times) --> Dash Panel Fuse --> Head Light Switch --> Brown Wire

    That Brown wire feeds a bunch of stuff (Clock, License Plate lamps, Front Parking Lamps, Rear Parking Lamps, etc.

    If you put the head light switch into Park, and all those things work with the exception of the passenger side park light (driver side front works, passenger rear works, driver rear works, etc.), then the issue can only be 3 things:
    • The passenger side front bulb is wrong/bad/burned out
    • The passenger side front socket is bad/contacts are dirty
    • The wire that feeds the passenger side socket is bad

    The first two are easy to check/confirm. If it's the 3rd, the wire, well since that same wire feeds a bunch of other stuff from the head light switch, and those other things work, we know it is NOT the fues, it is NOT the head light switch, and it is NOT the wire itself - UNTIL it gets to where it stops working. In this case, passenger side doesn't work, driver side does, therefore the issue has to be between the passenger side socket and where it connects to the driver side feed. I don't know why it doesn't work there, or what might have happened. But logically, that seems to be where the issue is.

    This all assumes you are measuring voltage correctly at the socket and stuff. Can you confirm the following:
    1. Driver side front parking light works
    2. Driver side rear parking light works
    3. Passenger side rear parking light works
    4. Driver side BULB placed into passenger side socket does NOT work
    5. Passenger side BULB placed into driver side socket DOES work


    Edit: of course, I could be missing something. I'm basing the above entirely on what you are telling me. Logically, I just don't see how it could be anything else. There are no relays or fuses anything in that Brown wire once it comes from the head light switch. However, this is based on the factory wiring manual. If you, or a previous owner, did stuff to that wire, then it's possible it's something else and not that wire. But again, because it's ONLY the passenger side, whatever was done had to be done between the passenger socket and where the wire joins the driver side. You are 1000% sure that there is no voltage on that brown wire at the socket, yes?
     
  20. 5-oh-MUSTANG

    5-oh-MUSTANG Well-Known Member

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    I can confirm all 6 of those things. Maybe i can look at the headlight switch again. It was very greasy but besides a kink in the wire harness somewhere this could be the only other thing i suppose.