Headlight headaches | FerrariChat

Headlight headaches

Discussion in '308/328' started by Vinsanity, Jul 16, 2017.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. Vinsanity

    Vinsanity Karting

    Sep 9, 2013
    225
    Washington, DC.
    Full Name:
    "VD"
    My normally very reliable and mild-mannered 85 QV is mad at me. I was out of town for a few months, and in my absence, her headlights started malfunctioning. First, they wouldn't turn on, (but went up) and then, they starting cycling up and down continuously. I've been a little busy since all this trouble started, so I only got to working on it today. Over a beer or two, my friend and I went through a number of trouble-shooting steps, as described below, with no luck, and have come to the rather baffling conclusion that both motors have a bad diode. I am never comfortable with the idea of simultaneous bilateral failures without an apparent common cause, so I will describe our methods and findings, in case any of you brilliant 308ers might have some insight onto what else I can try.

    Initial malfunction state: as of this morning, rotating the light switch to the ON position, (with stalk in center position) initiates an endless cycling of the headlight buckets (they go up and down, one slightly faster than the other, gradually getting off-phase). When the light switch is rotated to the OFF position, the lights turn off, and the headlights freeze in their current position (IE: they DO NOT self-park, as they should). Light motor cycling occurs identically in the other two stalk positions correlating to high-beams and parking lights. Lights do not illuminate in any switch or stalk position.

    First corrective action: removed light switch cap from stalk. Noted broken sodder connection on green wire. Fixed sodder connection, and reassembled switch.

    Result: Same exact behavior (cycling motors, no self-park) except that the lights now work (correctly in all three stalk-positions).

    Second action: removed and replaced 30 AMP headlight motor-control relay with (presumed) good spare.

    Result: No change in malfunction.

    Third action: Removed and replaced each individual 20/30 AMP motor relay with a known good relay from elsewhere on the panel.

    Result: No change in malfunction.

    Forth action: opened and checked resistance on the two connections to each headlight motor. Each motor has two pairs of wires. A black and black/gray pair, and a green, green/black pair. As we understand it, each pair goes to one of two diodes in the headlamp motor. We would expect detectable one way flow through each pair. So low resistance, measured in one direction across a wire-pair, and infinite resistance in the other direction across the same pair.

    Result: tested both motors, reading resistance each way across both pairs. We got the expected results (infinite, and 0.5) on the black and black/gray pairs on BOTH headlight motors, and we got the infinite in BOTH directions on BOTH of the green and green-black pair. In other words, we did not find a smoking gun. we found TWO smoking guns--which made us question our understanding of the system. All we know know is that they are either BOTH good, or they BOTH have one bad diode connecting the green and green/black wires.

    Fifth Action: just for GP, we left one headlight motor disconnected, and turned on the headlight switch, then reversed the configuration to test other side in isolation.

    Result: powered in isolation, each headlight exhibited the same behavior as previously, cycling up and down, and not self-parking when the switch was turned off.

    At that point, we were out of ideas that did not involve removing the headlight motors, cutting through the thick rubbery crud they are coated in, and trying to replace one or both diodes. That seemed like entirely too much work to start at 4:30 in the afternoon on a Sunday, when we had been messing around with various old cars since 9:30 in the morning.

    The one thing I thought of, but did not check was the steering column connection of the light switch stalk; but since the lights themselves illuminate correctly, (now that I soddered the wire in the switch back in) I kind of doubt that has anything to do with it.

    The only thing I can figure is that (maybe) having a broken/intermittent connection in the switch might have somehow damaged the control diodes in both motors. Seems far-fetched, but that is the only way I can believe the results I am seeing.

    That, or my car is just trying to punish me for my protracted absence.

    Any suggestions? Thoughts? Pearls of wisdom?

    Thanks in advance for the help.
     
  2. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,322
    Tallahassee, FL
    #2 thorn, Jul 17, 2017
    Last edited: Jul 17, 2017
    I had exactly this problem with my first car - a 1984 Corolla GTS. Every time the pods activated, they did a dance.

    At first, they'd both go up/down together and finally settle into the correct position. Later, they'd both dance, but get out of sequence. Finally, they got to the point that they were both randomly dancing to a different beat, and then would just stop in some random position (rendering the headlights useless). It was maddening.

    The dealer found the fix; as I recall (it's been 30 years) they replaced two 1-2" electrical boxes; I know at least one was a relay.

    So my gut tells me it's probably not your diodes; you're right - it's weird that they would BOTH go bad at the same time. If they have, then you've got (or had) another problem up the line that killed them both in the same moment.

    I also don't think it's your switch, btw.

    Another test to try: take off the cabin/electric cover panel. When they're dancing, are you hearing the relays click repeatedly? Or clicks with odd delays, or wrong # of clicks? Or is it just the initial "activation relay click", and then they dance regardless? If the relays keeping clicking, there's a problem area.

    If it's just once, then we know that switch+relay = proper signal to pods, therefore behavior = problem down the chain. If it's multiple clicks, then we can guess that signal = telling pods to go on/off repeatedly.
     
  3. Vinsanity

    Vinsanity Karting

    Sep 9, 2013
    225
    Washington, DC.
    Full Name:
    "VD"
    From my recollection (I'm nowhere near her right now, so I can't test my memory) I am getting multiple clicks from the relay board. I thought we had conclusively eliminated the possibility of a bad relay by swapping several out, but I wasn't able to swap BOTH light relays at the same time, because I only had one known-good spare. Short of breaking open two potentially four-oh motors, that is probably worth looking at again.

    Thanks.
     
  4. Patrick Dixon

    Patrick Dixon Formula 3

    Mar 27, 2012
    1,083
    UK
    It's not just a bad relay that you need to watch for, you might have a bad connection on the relay board. Use some contact cleaner, Servisol or similar, and spray it in all the contacts before you refit the relay. Also check the connectors on the back of the relay board.
     
  5. miketuason

    miketuason F1 World Champ
    Owner Silver Subscribed

    Feb 24, 2006
    15,517
    Cerritos, CA.
    Full Name:
    Mike
    #5 miketuason, Jul 17, 2017
    Last edited by a moderator: Sep 7, 2017
    This could be your culprit, one of the wire or both wire sometime comes unsolder in side the rotating knob. I had the same problem befor, resoldered the wire and all is good now.
    Image Unavailable, Please Login
     
  6. braq

    braq Karting

    Mar 29, 2010
    225
    Hill Island
    Full Name:
    Paul XXXcX
    he wrote he re soldered...
    over time things corrode...without checking the wire diagram...is there a ground connection to the motors that may have gone bad? For testing you can just run a fresh ground wire from battery/chassis to the point on the pods. The other is actually connectors, so if there is a male/female connector along the way, unplug, check maybe scrape/use deoxit type cleaners. The board of course is also a possible source. Good luck!
     
  7. ME308

    ME308 Formula 3

    Nov 5, 2003
    1,542
    Munich, Germany
    Full Name:
    Michael
    this !

    press (very) hard on the relais - one at a time - while the headlight motors are dancing

    see what happens
     
  8. Vinsanity

    Vinsanity Karting

    Sep 9, 2013
    225
    Washington, DC.
    Full Name:
    "VD"
    Believe me, I was very excited when I first took off the stalk end cap and saw that broken solder on the green wire. I was commensurately annoyed to find out that doing so did not solve my problem.
     
  9. Vinsanity

    Vinsanity Karting

    Sep 9, 2013
    225
    Washington, DC.
    Full Name:
    "VD"
    I would think that a bad ground would stop the motor from working entirely--not send them dancing up and down. But yeah, I suppose I should eliminate that. Thanks.
     
  10. Vinsanity

    Vinsanity Karting

    Sep 9, 2013
    225
    Washington, DC.
    Full Name:
    "VD"
    I DID check the back of the board to see if any of the wires were out, but I can't say it was an exhaustive look. We did not check for corrosion and individual circuit integrity. That probably merits closer examination. Good point.
     
  11. Archer911

    Archer911 Formula Junior

    Sep 26, 2016
    907
    New England
    Full Name:
    Tim
    I am also having this problem intermittently.
     
  12. Vinsanity

    Vinsanity Karting

    Sep 9, 2013
    225
    Washington, DC.
    Full Name:
    "VD"
    I'll let you know when I solve it!

    Today, I bought a few replacement relays, and swapped out all three of the headlight motor-related ones simultaneously. No change. Now I have some extra relays though...

    I have a plan to test the headlights motors on my friend's 308 using the same protocol I used on my car. If I get the same results, I can say with reasonable certainty that the fault lays elsewhere. If the result differs, I will tear open my motors and swap out the diodes.
     
  13. Saabguy

    Saabguy Formula 3
    Silver Subscribed

    Mar 28, 2012
    1,753
    Shreveport, LA
    A bad ground could give you a ground loop where the current flows backward through something. Like putting in the wrong type of turn signal bulb, weird things happen. The real question then is which ground and where is it.

    Keep us posted!

     
  14. braq

    braq Karting

    Mar 29, 2010
    225
    Hill Island
    Full Name:
    Paul XXXcX
    Exactly, either find if there is one towards the motors or consult the diagram.

    Back in the day, there was odd circuitry going on, like window regulators in the 60s that were permanently on 12V and you'd switch one or the other winding onto ground, depending which direction you'd go.
     
  15. TonyL

    TonyL F1 Rookie

    Sep 27, 2007
    3,811
    Norfolk - UK
    Full Name:
    Tony
    On my car I did most of the things you have tried but eventually I stopped and looked at the problem In greater detail.

    What you have are two motors that drive the pods up and down via linkages, when somebody operated the switch while I looked at the linkage movement I noticed a lot of sloppiness in the arms and rose joints.

    After removing and fixing the worn out bits I reassembled them.

    If not set up correctly the motors will just keep turning on a continuous cycle loop as they cannot find their off / on position, the motor has to move 180 degrees to switch on (say at 12 o clock) and then 180 degrees to switch off ( say 6 o clock) If it passes these points then it just rotates to the next position and so the problem just continues, hence the winking of the headlights.

    To solve the problem I adjusted the linkages when when the motor rotates 180 degrees each time, they now work perfectly.

    Be extremely careful with fingers, the motors are powerful.
     
  16. Vinsanity

    Vinsanity Karting

    Sep 9, 2013
    225
    Washington, DC.
    Full Name:
    "VD"
    I did think to check the linkages for slack--though I only did so when they were static. Everything seemed very firm, but I didn't watch them closely in action. It will probably be a few days before I get back to the garage and start messing with it again, and I will recheck those. Thanks.
     
  17. NW328GTS

    NW328GTS Formula 3

    Nov 16, 2009
    2,191
    Washington
    Full Name:
    Hal
    did you check the voltage at the headlights? low voltage can cause weird behavior. If the voltage is good (12.6) under no load... check it again with a 30-40W load. A significant voltage drop could cause the light to think its off and so it would stow... once the load is removed the voltage goes back up and it tries to re deploy... and the cycle begins. If the voltage is low to begin with the same behavior can occur.

    You can always power the light directly at the headlight connection to the motor and see if the light responds correctly

    If the voltages are cycling you have a bad connection somewhere.
     
  18. Vinsanity

    Vinsanity Karting

    Sep 9, 2013
    225
    Washington, DC.
    Full Name:
    "VD"
    Interesting point. Trying to figure out exactly how a system works while trouble-shooting it is never optimum. My hunch is that power isn't a problem, just based on the speed the motors are going up and down, but a hunch is no substitute for a volt-meter, so I will verify :)
     
  19. NW328GTS

    NW328GTS Formula 3

    Nov 16, 2009
    2,191
    Washington
    Full Name:
    Hal
    make sure you check for low voltage under load. Put the meter on the connection and cycle the light. if you have a bad connection somewhere it can put out a decent voltage under no load and still have high resistance and so low voltage under load. A headlight is typically 55 watts and Ferrari's are not known for the quality of wiring design. A lot of the wires are undersized and the connectors are not the best. The fusebox is only one example.
     
  20. CaptOharry

    CaptOharry Formula Junior

    Jan 4, 2009
    755
    Green Cove Spgs FL
    Full Name:
    Harry Welch
    Well you Jinxed me Vince, just went out to check my lights.
    I turn the switch one light pops up,goes down ,turn switch again
    other pops up.
    Seems the switch in steering column has a bad connection.If i pull out on it all lights work. looks like I'm gonna pull the steering wheel and have a look see.
     
  21. Vinsanity

    Vinsanity Karting

    Sep 9, 2013
    225
    Washington, DC.
    Full Name:
    "VD"
    Oh no! Sorry about that. So we have the same cars, the same posters on our wall, and now, the same random headlight malfunction. Let me know how your steering column explorations go. I'll be in touch.
     
  22. Saabguy

    Saabguy Formula 3
    Silver Subscribed

    Mar 28, 2012
    1,753
    Shreveport, LA
    #22 Saabguy, Jul 23, 2017
    Last edited: Jul 23, 2017
    That sure sound like a wonky relay or connector. Gets enough current to activate one circuit but not both. YMMV.


     
  23. CaptOharry

    CaptOharry Formula Junior

    Jan 4, 2009
    755
    Green Cove Spgs FL
    Full Name:
    Harry Welch
    Just fixed,the problem was in the tumbler end of the switch
    the Green wire had come loose making random contact, also I found that between the end Contacts,there was some Carbon/Soot.
    I soldered the wire back on and cleaned the contact.
    Happy to say all is working properly.
    Also make sure you put the check ball back in the upper recess. All the Best.
     

Share This Page