89 TR Electrical Issue (Need Advice) | FerrariChat
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89 TR Electrical Issue (Need Advice)

Discussion in 'Boxers/TR/M' started by erisol, Mar 7, 2015.

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  1. erisol

    erisol Rookie

    Jan 28, 2007
    27
    Scottsdale, AZ
    Full Name:
    Eric S.
    #1 erisol, Mar 7, 2015
    Hey Guys, hope everyone is enjoying their weekends. I had the car out today (beautiful day here in Scottsdale). I had it out for a few hours this afternoon on some nice roads. I am a new owner and I am still getting familiar with the car. It runs like a freight train. No issues in that department. Here is my issue. I went to turn on the parking lights tonight and I noticed the following: The speedometer dashboard lights went dim, the speedometer began to act erratically and both the left and right turn signal lights on the dashboard were illuminated. The same issue persisted when I moved the stalk to turn on the headlights from the parking light position. If I turn off the headlights and parking lights, the speedometer acts normally and registers correctly, BUT the right side turn signal light on the dashboard will not illuminate when the stalk is moved to the right. Outside the car, the turn signals appear to work just fine. My issues are confined to the speedometer and the dashboard. Lastly, my flasher does not appear to work at all when the button is depressed on the console. It appears not to function at all. This holds true whether the parking lights are on/off or headlights are on/off. Occasionally when driving with the headlights on, the speedometer dash lights will come back on with full illumination, but then it returns to dim. The tachometer is not affected by this at all and the dash lights remain fully bright. Feels like I have a bad ground somewhere, OR that the headlight switch/stalk is bad, but I do not know why that would have an effect on the flasher. The headlight stalk/switch on my 308 is a problem area (I am told). Does the same hold true for the TR? Any advice would be appreciated. Thank you everyone.
     
  2. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
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    romano schwabel
    #2 turbo-joe, Mar 7, 2015
    I think there are 2 failures:
    one is ground at the dashboard and the other is the flasher switch.

    are the blinker indicator lights left is working when you switch on the turnsignal switch left and only not when you switch to right? are they both working when the flasher is activated?
     
  3. erisol

    erisol Rookie

    Jan 28, 2007
    27
    Scottsdale, AZ
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    Eric S.
    #3 erisol, Mar 7, 2015
    If I put left blinker on, the green light on dash blinks. If I put right blinker on, the green light on dash doesn't blink. Flashers do not work at all.
     
  4. turbo-joe

    turbo-joe F1 Veteran

    Apr 6, 2008
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    #4 turbo-joe, Mar 8, 2015
    so I think as already mentioned:
    the flasher switch is not working right ( you may take it out and dismantle and clean it, may be something inside is broken or only corroded )
    you have ground problem at the dashboard ( take a 4 mm² wire and put this directly from the battery minus to a ground wire at the dash, if then all is fine you may look where there is bad connection, if same problem then - happy searching :) )
     
  5. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
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    Jan 11, 2001
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    Steve Magnusson
    #5 Steve Magnusson, Mar 8, 2015
    This is a good sign that: A) +12V power is reaching the turn signal system from the emergency flasher switch (although +1 to having a look at getting your emergency flashers system working), and B) The same flasher serves both systems so having at least one of your turn signals working = the flasher is OK.)

    The left and right side turn signals are independent of each other downstream of the turn signal switch, and, upstream, they share the same single +12V wire coming from the emergency flasher switch = your emergency flasher switch is at least still (correctly) supplying this +12V power (even though something else must be messed up there).

    I would've put a 90% probability on the turn signal trouble just being debris/crud in the Frankenstein contacts for the RH side in the turn signal switch, but that doesn't agree with your previous note that: "Outside the car, the turn signals appear to work just fine" -- Do you really mean that the outside RH turn signal lights will be flashing while the RH green dash light does not flash at the same time/same attempt-to-use? Or is it erratic -- meaning, on some attempts-to-use, nothing on the right side works (not inside nor outside), but, on other attempts, the right side (both inside and outside) is OK?
     
  6. erisol

    erisol Rookie

    Jan 28, 2007
    27
    Scottsdale, AZ
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    Eric S.
    #6 erisol, Mar 8, 2015
    Found it! There is a wire below the dash that somehow gets moved when the steering column is adjusted. I was able to reach down and put my hand on the wire and when I move it ever so slightly the speedo dash lights go to full bright and the speedo no longer acts erratically AND the 4-way flashers work. I am not sure what the issue is with this specific wire or where it goes, but I moved it over to where it is no longer causing the issue. I think that it could move if I go over a bump or something, so I would like to get it secured properly. This may be a 2-man job. One under the dash with hands on the wire to make sure that it's the correct one and another in the seat watching the speedo dash lights to see if it's acting-up. Basically THIS ONE WIRE is what is causing all of my issued EXCEPT ONE THING. No matter what, even if the 4-way flashers are on, OR if the turn signals are on independently, the interior light below the speedo that shows that the RIGHT hand turn signal is "ON" does not illuminate. The left one illuminates just fine, but the right one does not. I reconfirmed that the turn signal lights outside of the car work just fine on all four corners. This is the only mystery left at this point.
     
  7. turbo-joe

    turbo-joe F1 Veteran

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    #7 turbo-joe, Mar 8, 2015
    great that you found the mistake so fast :)
     
  8. 302Tim

    302Tim Formula 3

    Jul 2, 2011
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    Tim
    #8 302Tim, Mar 8, 2015
    You can solve both problems at once--the non-working light on the central instrument housing is likely just a bulb. To replace the bulb you will need to remove the instrument housing which will have you disconnect the three wiring connectors just under the dash which is where your loose wire/bad connection is.

    CENTRAL (main) INSTRUMENT HOUSING
    NOTE: Housing can be removed with steering wheel installed though it is easier if removed.
    1. If desired, remove steering wheel.
    2. Disconnect three electrical connectors under dash (by steering column).
    3. Release lever, tilt steering column fully down.
    4. Remove one 10 mm flange nut and fender washer and remove lower [trim] cover (above steering column/below instrument housing). This is difficult at best with the steering column and/or steering column covers in place. You may need to remove the upper steering column covers or lower the entire column. On later U.S. cars with knee protection bolster, column can’t be fully lowered with bolster in place.
    5. Remove two 10 mm bolts (early) or 10 mm flange nuts (late) securing instrument housing to dash (located behind lower cover).
    6. Carefully rotate assembly upward and forward to release two forward tabs.
    7. Remove housing, carefully feeding three electrical harnesses up through dash.
     
  9. erisol

    erisol Rookie

    Jan 28, 2007
    27
    Scottsdale, AZ
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    Eric S.
    #9 erisol, Mar 8, 2015
    Thank you very much. This will be next weekends project. I will report back after the surgery.
     

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