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Wire Connections At Starter On 91TR(US)

Discussion in 'Technical Q&A' started by Shamile, Mar 21, 2004.

  1. Shamile

    Shamile F1 Veteran

    Dec 31, 2002
    6,563
    Lakeland FL
    Full Name:
    Shamile
    Dear Ferraristi,

    I was wondering if anyone knows which wires should go to which connectors on the back of the starter. In my case there is an aftermarket relay between the starter and the wiring harness. I assume this is from an alarm system starter-interupt. I have been removing the non=oem crap and this didn't look right. ( the cheap blue Radio Shack connectors gave it away. :)

    There is no wire from the relay to the rest of the car...one spade on the relay is also unused. ( The car starts just fine...no problems )
     
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  3. carguy

    carguy F1 Rookie

    Oct 30, 2002
    3,336
    Alabama (was Mich.)
    Full Name:
    Jeff
    Not sure, but I believe that in the past some cars had starting problems caused by low power at the starter, so an extra solenoid was added to bypass the "system" and provided a full battery power to the starter. My TR had this done by a previous owner. I've never had any starting problems so I've left it on the car....although I did relocate it out of sight. I wonder if your car had a similar problem in the past? Or it could be as you say....part of an anti-theft system. I'll try and find a pic of the wiring. Hopefully someone else will chime in and be able to answer your questions.
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    20,499
    Texas
    Full Name:
    Steve Magnusson
    Shamile -- the connections at the TR starter solenoid are:

    Terminal 50: white wire. This is the line from the ignition key switch that (theoretically) goes +12V when you put the key in the "start" position (although it's often somewhat lower, +8V~+10V, due to the switch contacts, long wire lengths, connections at the fusepanel, etc.)

    Terminal 15A: white/blue wire. This line should go +12V when the plunger inside the starter solenoid moves (which closes the internal switch and also puts +12V power on the starter motor). It's used to "tell" the injection/ignition system that the engine is cranking over/trying to start.

    Terminal 30: This is the threaded stud that has a huge wire from the battery and a huge wire going to the alternator output (so it's always +12V). It will also have a small yellow/red wire that goes to supply +12V power to the injection system.

    (If you've got additional unused terminals on the starter solenoid it was probably replaced with a quasi-equivalent at some time.)

    Like carguy noted, a relay is sometimes added so that, rather than using the wimpy 8~10V coming down the white wire to energize the solenoid, the (wimpy) white wire voltage is used to close the relay which then more directly puts (a stronger) +12V on terminal 50 of the starter solenoid.

    Do a search at the old site on "TR solenoid" (and mode, whole words only) -- plenty of homework for you ;).
     
  5. Shamile

    Shamile F1 Veteran

    Dec 31, 2002
    6,563
    Lakeland FL
    Full Name:
    Shamile
    Dear Ferraristi,

    Gawd! Is there never an easy answer with a Ferrari?

    Well....Thanks Carguy and as always Steve Magnesson (91TR )

    I will print this out and stand behind the car and scratch my head a few times. :)
     
  6. Shamile

    Shamile F1 Veteran

    Dec 31, 2002
    6,563
    Lakeland FL
    Full Name:
    Shamile
    Dear Ferraristi,

    91TR & Carguy, Ya'll Da Man ! :)

    That relay in at the starter turned out to be exactly what you said. It was a modification to bring more voltage to the selinoid. Steve, the white wire went exactly where you said. Soooo....I guess it stays. Like carguy, I'm going to make it look a little more OEM though.
     
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