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Flickering Headlights

Discussion in 'Technical Q&A' started by vrsurgeon, Nov 6, 2010.

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  1. vrsurgeon

    vrsurgeon F1 World Champ
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    #1 vrsurgeon, Nov 6, 2010
    Hello everyone. My 1999 euro 360 has this "peculiar" issue since I bought her.. her headlights flicker off and on when I turn them on. Almost acts like a connection is loose.. It does this with both high beams and low beams, but only when the engine is running!

    No burned out fuses. I added extra grounds to the low beams in the front of the car thinking it was a grounding issue. No change. I then tracked down the wiring to relays 86 and 87. Relay 87 buzzes on and off, clicking this way and that, the lights flickering in unison.
    It appears the current to relay 87 is being finicky when the engine is on.

    Has anyone encountered this besides me? Does anyone have any ideas what actuates relay 87? White and grey wires. I'm hoping it's not regulated by the ECU...

    Many thanks!

    Curt

    ps- I'll be working on this and will post whatever I find for posterity. Any help is very appreciated. Gotta love the quirks of ferrari electrical systems. :)
     
  2. Paul_308

    Paul_308 Formula 3

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    #2 Paul_308, Nov 6, 2010
    The engine involvement is likely just the vibration it provides to the area. You may have a bad ground at the relay panel. Learn the wiring of the noisy relay, it may be printed on the side. Then use a test lamp (not a meter) to learn if voltage to the coil is intermittent. First placing the test lamp to car ground, then to the ground at the relay socket. Once you've eliminated coil voltage and ground, place a jumper wire to the relay socket bridging the contacts pins. If still have flickering it has to be wiring between the relay socket and the headlights, or at a socket along its route.
     
  3. vrsurgeon

    vrsurgeon F1 World Champ
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    #3 vrsurgeon, Nov 6, 2010
    Paul, thank you. That is tomorrows project, jumping the relay contacts and trying that while car is running.. The problem is that the darn wiring charts are a pain in the --- to follow.

    Thank you for responding. :)

    I'll post back what I find... :)

    Curt
     
  4. vrsurgeon

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    #4 vrsurgeon, Nov 7, 2010
    So apparently relays 86 and 87 both have a white wire that lead connector 26h (out to starter). Both white wires share a common contact (I think leading out to the starter). I disconnected the white wire on connector 26h (the one in the center) coming from relay 87 (15 amp services).. and the flickering went away completely as well as the relays stopped buzzing.. car starts fine and charges fine..

    I suspect that there may have been a short farther out by the starter..

    Apparently solved... I'll keep this thread updated...

    Short: if headlights flickering and relays 86 and 87 clicking away.. try disconnecting white line from relay 87 (15 amp services) at connector 26h (white connector in drivers side rear electrical area with two white lines heading to the starter). Hopefully this works for you.

    Cheers! Curt
     
  5. vrsurgeon

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    #5 vrsurgeon, Nov 7, 2010
    False alarm.. Still flickering after test drive. Short must be elsewhere... back to the sleuthing.. :-(
     
  6. vrsurgeon

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    #6 vrsurgeon, Nov 7, 2010
    I grounded this white wire to a bolt holding the alarm module cover in the rear compartment and it apparently worked to stop the relay clicking in real time. Apparently this ground is loose in the engine compartment. Will update only if this does not solve the problem. So far everything solved.
     
  7. vrsurgeon

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    #7 vrsurgeon, Nov 21, 2010
    Latest update. The ground did not work.. just blew out the fuse for the starter relay. :-( So have isolated to the 12v services relay. Ended up removing the relay (actuation in relay is independent circuit from starter and other circuits), jumping the 12V services relay (87) and now things run beautifully. Must be a bad connection somewhere in the wiring loom... Headlights work fantastic. Car starts fine, no error lights, no drain, only side effect is that my lights work when I have no key in the car. I may adjust this by running a relay from the key controlled devices relay that then actuates only when the car is on at a a later time.

    May one day find the short until then, I'll be enjoying the car. :)
     
  8. climb

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    #8 climb, Nov 21, 2010
    Maybe a relay harness hooked up from the battery to the headlight switch.
     
  9. james patterson

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    #9 james patterson, Nov 22, 2010
    I have repaired this or similar problem before on a car (2000 Euro 360) that would flicker the headlights while being driven. Turned out to be the 'keyed on/off' relay that turn the lights off during starter engagement. The culprit was the connection on the starter that operates that relay. Sorry I don't remember more detail.

    Hope that helps.
     
  10. CaptOharry

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    #10 CaptOharry, Nov 22, 2010
    Sounds more to me the Diodes in the Alternator/One or more are bad.
     
  11. dino clay

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    #11 dino clay, Nov 23, 2010
    first change the relay, lights fans and starters draw the most current, that's amps. Voltage remains the same, 12v.
    Pull any relay from some other circuit and try it in the problem child. The relay is a switch like the light switch.
     
  12. vrsurgeon

    vrsurgeon F1 World Champ
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    #12 vrsurgeon, Nov 23, 2010
    This is why I love ferrarichat. You guys are great for answering. :)

    I tried the "bad relay" hypothesis.. was an idea of mine as well.. switching around.. same symptoms. Diodes and alternator.. thought that too but all other circuits are fine.. good thought though..

    I agree with the starter loose connection.. somewhere in the wiring loom. I tried to find the silly thing but couldn't isolate it, I suspect in the engine compartment where it goes out to the starter. I also thought the relay that disengages the starter when the charger is plugged in.. that also had no effect although I bridged that relay as I do not use the charger and I saw that one line on the wiring chart went to the instrument panel.

    I will one day track the thing down.. for the time being they used the same wiring (+) to the starter relay and it looks like its in parallel to the relay coil in the 15A services relay. I'm going to find a circuit (I'm thinking cigarette lighter if possible) that is only active when the key is in the ignition (I even considered bad connection there with vibration at one time) and since I don't smoke run this to activate the relay with the key in position 2. Teh relay should actuate with very very low current draw. I want to enjoy the car and have some other issues to work through before perfecting this this one. :)

    Guys many thanks for your thoughts on this thread. It is appreciated!
    BTW an old fashion wiring diagram would be sweet.. perhaps one rainy day I'll compile and put online..
     
  13. Paul_308

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    #13 Paul_308, Nov 23, 2010
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    Interesting puzzle. Posted 2 diagrams, the starter wiring since it has come up in the discussions several times, and the whole car harness cuz it looks cool. Wiring harness at the relays is insane and no picture will help there.

    Since there is a relay which turns off the headlights when starting the car, and that relay chatters when the engine is running, either the 'services' or 'headlight' relay is either getting false signals to turn off the headlights (voltage from the starter wire) or is not holding it's headlight contacts closed under vibration. Since the relay buzzing is constant, it's likely getting unwanted voltage from another source. Your thought of bridging it with another relay is interesting but I wouldn't give up on the proper solution yet. Something logical is causing this interruption to the normal relay voltages.

    Do you have the Modena or Spyder? What wiring document(s) do you have? I have the 360 Spyder Wiring pdf but it is only harnesses, connectors and ground charts. No old fashioned wiring diagrams unfortunately to my knowledge.
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  14. DrStranglove

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    #14 DrStranglove, Nov 23, 2010
    How did this post get added to my subscribed post box?
     
  15. vrsurgeon

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    #15 vrsurgeon, Nov 24, 2010
    Last edited by a moderator: Sep 7, 2017
    Paul,

    I have a 99 modena. I am using the spider wiring diagram with the connectors and ground charts that I downloadable... I traced throught the document to come up with this:

    Both the 15A services relay and the starter relay were buzzing in unison with teh flickering. The flickering is proportional to engine speed and vibration.. hence I think a bad connection.. Furthermore, I suspect it is where both go to the starter in the engine compartment perhaps s172h on the diagram. either grounding or loosing connection. Since it appears the current to close the 12A services relay comes from the starter relay. FO note, when I disconnected the wire to 12A services relay from connector 12H, the buzzign continued.. so it might lead to concluded that s120H or later is the culprit...
    I'll probably run an aux input to the starter next time I have the car on the lift. When on the lift a couple of weeks ago the connection to the starter relay was adequate.
    Aaaahh. Electrical gremlins. A puzzle. :)
    Thanks for the input on this!

    -Curt
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  16. dino clay

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    #16 dino clay, Nov 24, 2010
    Sorry, this is giving me a headache. Good luck but I am taking two and going to bed. May the force be with you.

    clay
     
  17. Paul_308

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    #17 Paul_308, Nov 24, 2010
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    I have redrawn the diagram to more easily apply electrical logic and marked the buzzing relays in blue. I conclude there is voltage inappropriately being applied at the red arrow. And this could be bad for the starter solenoid relay. If voltage were coming back from the starter as you theorized at one point, the starter relay would not buzz, ONLY the 15A services relay, so I chalked that off.

    If the ground on either the starter relay or the 15A services relay were a problem you wouldn't get these symptoms, it would present in the inability of either of the relays to energize, not having them energize at a wrong time (the buzzing).

    Red arrow - this should have voltage ONLY when the operator turns the key to position III which energizes the line to the Charger/Starter-Disable (CDS) relay which closes and opens contacts on the 15A Services relay. The next question is whether that voltage at the red arrow is coming from the non-buzzing CSD relay contacts or from a volunteer short within the harness. I see the easiest way to determine this is to start the engine then remove the CSD relay. It has no function once the engine is running. My logic - if the two buzzing relays immediately quit buzzing, it must be a fault of the CDS relay contacts. Since the CSD relay itself isn't buzzing, it isn't receiving voltage causing it to energize and close it's contacts. Why it's contacts are closing could be a bad spring which holds them open or the contacts are just too close and vibration is aiding their mischievous behavior. Of course the cure is replacement. If the relay isn't causing this...i.e. if the buzzing continues with that relay out, that's a story for another day.

    Where did you get the circuit? My 2000 360 Spyder Wiring pdf starts at L4.01 and is 80 pages.
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  18. vrsurgeon

    vrsurgeon F1 World Champ
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    #18 vrsurgeon, Nov 27, 2010
    Last edited by a moderator: Sep 7, 2017
    Ok. so I probably should preface this by adding that over the last 3 days, when I twist the key.. the starter would not even crank. So I put her up on blocks (I know.. how redneck, but effective! ;-) ) and dropped the pan to check out the starter..

    The connection from the relay to the starter was loose... see pic..

    Tightened it so it would not rattle or wiggle.. and problem SOLVED!

    power to starter relay and 15A devices relay comes from this connection.. so as it rattled, the connection was being interrupted, and thus the relays buzzed and the lights flickered.
    By fixing this loose connection at the starter relay.. all is solved and 2 problems solved with one stone.

    My thanks to everyone for helping with this.. remember in future if starter occasionally not turning and buzzing relays, look at connections at starter..

    All the best with many thanks! Curt
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  19. Paul_308

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    #19 Paul_308, Nov 27, 2010
    Last edited by a moderator: Sep 7, 2017
    I'm happy you found and proved the solution. In reconciling the circuit drawing, the bottom left wire from other areas must carry +12v rather than ground. The 15A Circuit Relay coil would require a stable ground through the starter solenoid's low impedance coil to activate the relay, keeping headlights on. We used to call these 'trick' circuits but it is what it is. When the starter is activated by the key, both sides of the 15A Services Relay coil then become +12v and it opens up voltage to various areas including headlights.

    In redrawing and analyzing the circuit below, the Starter Relay would not be buzzing together with the 15A Services Relay. Not a biggie as it would be quite easy to mistake the location of buzzing or chattering in close quarters. The left side of the Services Relay coil now figures to be +12v instead of ground. There aren't any real clues on the original circuit and if the Starter Relay were truly buzzing as well, the analysis fails.

    Ya gotta love a good puzzle. Glad it's found, and if that loose connection happened to one 360 it can happen to another. I'd still like to know the source of the original circuit drawing...it might be helpful later.
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