Potential electrical short on 90 TR | FerrariChat

Potential electrical short on 90 TR

Discussion in 'Boxers/TR/M' started by Testarossabear, Dec 12, 2022.

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  1. Testarossabear

    Jul 28, 2022
    27
    Orlando, FL., USA
    Full Name:
    Andrew Girges
    Hello all,

    my 90 TR has aftermarket HID lights. I recently picked it up from the shop after timing belt service and my RH headlight is out. Upon turning on the headlights, both headlights come on, and then 5 seconds later the RH headlight shuts off. I’m not sure if this is related, however my tail lights are out of wack wirh the brightness.

    If headlights are off and breaks are applied, the left break light is visibly brighter than right

    when headlights are on, and breaks are applied, the right break light is visibly brighter than left.

    When headlights are on, and driving (no break lights) the RH tail light is noticeably brighter.

    Haven’t checked all fuses but checked RH headlight fuse and it’s fine.

    Any suggestions regarding troubleshooting? I don’t think my headlamp needs replacement, I think it may be something silly.

    Thank you in advance
     
  2. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    9,540
    southwest Germany, France ( Alsace ) and Thailand
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    romano schwabel
    this sounds like a ground problem
     
  3. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,826
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    Are you saying:

    1) that you know everything was working correctly, the service was done, and now you have the problem you describe,

    or

    2) You don't know if was working correctly before the service?
     
  4. Testarossabear

    Jul 28, 2022
    27
    Orlando, FL., USA
    Full Name:
    Andrew Girges
  5. Testarossabear

    Jul 28, 2022
    27
    Orlando, FL., USA
    Full Name:
    Andrew Girges
    the first pic is break lights with headlights off. 3rd pic is break lights with headlights on (RH headlight is out)
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,826
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    And the 2nd picture is? Just headlights "on" (no brakes)?

    I'll post some pics in the morning, but (unless your photos just don't show it) you've got a bunch of rear taillights not working. See page 94 in your OM:

    For the brakes = one bulb in F & the more inboard bulb in C should illuminate brightly (your Fs look dead on both sides)

    When the headlights (running lights) are "on" = the inboard bulb and outboard bulb in C should both illuminate (and both your outboard C lights don't look like they are working)

    I'll warn you that getting the rear bulb holders out can be difficult, and it's easy to break the legs off of them -- so don't apply torque to the ends of the legs (apply the torque as close to the base as possible). The sockets and bulbs can also have problems (like the solder ball on the end of the bulb deforming over time and/or corrosion). Think you'll need to inspect the bulbs and socket to first make sure all the bulbs are OK and of the right type.

    I'll admit that I cringed a little when you mentioned having "HID" headlights as doing a high-quality HID ballast installation is not easy (and often +12V power is pirated from a place it shouldn't be pirated). I don't think that your headlight issue has anything to do with the rear taillight problems -- but maybe might be based on how it was installed. Have you ever looked at how this was done? Any horrible "Scotch-lok" connectors or other terrible wiring modifications? I'd be more suspicious of a ballast problem for your RH headlight going out after some brief runtime (i.e., something heats up and pukes).
     
  7. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
    9,540
    southwest Germany, France ( Alsace ) and Thailand
    Full Name:
    romano schwabel
    I think that the bulbs are not correct in the holder. so on one side the normal rear light is on and the other side is the brake light. shut off the light, turn on the ignition and tell a friend to sit in the car and brake. then I´m sure it is exact otherwise
     
  8. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,826
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    71veedub likes this.
  9. Testarossabear

    Jul 28, 2022
    27
    Orlando, FL., USA
    Full Name:
    Andrew Girges
    many thanks for this diagram Steve and thank you for your input turbo-joe. ill be further troubleshooting later today and keep yall posted!
     
  10. Testarossabear

    Jul 28, 2022
    27
    Orlando, FL., USA
    Full Name:
    Andrew Girges
    Alright y’all, reporting back.

    A couple of the housings for the light bulb seems to have gave out and needs replacement….as in its no longer keeping the bulb in place. Posted a pic for reference. Where do you suggest me sourcing this? I purchased identical bulbs (or so I thought) however I realized that the larger bulb in C Is a has a different base?

    Attached are pics. Seems like the configuration is smaller bulb on the outside, larger double base on the inside.

    Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
     
  11. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,826
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    That two-filament bulb for C inner (the middle of the bottom row) should be OK (even though the shape of the solder balls on the ends are a little different). I think you'll just have to try to clean up your existing bulb sockets as best you can as they are an F TR only part AFAIK (Unobtanium Supply sells reproductions of the plastic portion, but the metal bulb socket itself is reused -- and it's not easy to reassemble them well).

    C outer and F both use a single filament bulb of the same overall size and base, but C outer is a low light output while F is much brighter light output. There should be some sort of wattage (W) marking on your old bulbs to use as a reference.
     
  12. theunissenguido

    theunissenguido F1 Rookie
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    Jan 21, 2004
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    Guido
    A good video showing back lights (and other) at night...on a US model.
     
  13. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,826
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Can't agree -- it's got the wrong wattage bulb (too bright) in the C outer position. The running light filament in the dual-filament C inner bulb and the running light filament in the single-filament C outer bulb should be the same (low) wattage.
     
  14. theunissenguido

    theunissenguido F1 Rookie
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    Jan 21, 2004
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    Yeah, You are right Steve, ....but wanted to share nice looking woman also...:D
     

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