Starter Solenoid | FerrariChat

Starter Solenoid

Discussion in '308/328' started by BrockBenson, Jan 8, 2023.

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  1. BrockBenson

    BrockBenson Formula Junior

    Oct 18, 2018
    277
    Australia
    Hello,
    Has anyone ever tried pulling apart the starter solenoid (Bosch) as fitted to 308QV's? My starter is playing up, intermittently I just get a clicking sound from the starter. I checked everything else, battery, ignition switch, wiring, grounds, voltage at starter, etc. all seem fine. Fitted new brushes to the motor as they were worn, but I suspect it might be the contacts inside the solenoid? From what I've been able to find (or not find!) this solenoid is NLA. So I'd like to open it up and see if the contacts are burnt. Got the idea from this post below on a Dino starter rebuild (though that one is an MM type).

    https://www.ferrarichat.com/forum/threads/repairing-246-starter-motor.444350/#post-143060785

    Tried un-soldering the contacts, but the cap still seems solid and won't come off.
    Any ideas or experience anyone?
    Thx, BB
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  2. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    6,870
    Full Name:
    Mike 996
    I have no personal experience with this particular solenoid, though it looks typical. From the pic it appears to be crimped together, which is common. If so, disassembly would be a bit of a pain though do-able.

    FWIW, my 328 did the same thing on start-up, only a single click from the solenoid and it turned out to be the ignition switch/connections though I realize you checked that already...
     
  3. Lawrence Coppari

    Lawrence Coppari Formula 3

    Apr 29, 2002
    2,190
    Kingsport, TN
    Full Name:
    Lawrence A. Coppari
    My '87 328 would occasionally make only a click when I turned the key. I removed the starter and tested it with a battery, and it always worked. I also took it to a shop that repairs starters. They said it was fine. My problem is the connection at the rear of the car near the frame on the heavy wire that always is hot. On my 328 it is the same type of connection that is on the battery ground connection up front. This problem occurs about every 12 months. I clean the slide-together connection and the problem goes away. I do not know if your 308 has the same slide together connection. I also got rid of the slide-together switch up front and replaced it with a good manual switch about 20 years ago.

    I also installed a fly-back diode to protect the ignition switch.
     
  4. BrockBenson

    BrockBenson Formula Junior

    Oct 18, 2018
    277
    Australia
    Yes, I've had the start switch out and it bench tested fine. I also put the multimeter between the IGN switch wire and the starter (down near the starter) and waited for it to do the "no start click" thing again, and even then I'm getting 12.4v

    I'm not sure what you are referring to? I thought the heavy +12v cable runs from the battery to the starter uninterrupted? Are you saying there is some sort of terminal connection in line?

    Thx BB
     
  5. Lawrence Coppari

    Lawrence Coppari Formula 3

    Apr 29, 2002
    2,190
    Kingsport, TN
    Full Name:
    Lawrence A. Coppari
    On my 328 there is a connection a couple of feet from the starter towards the front of the car. It's covered up by a plastic cover held in place by two bolts to shield it from road grime. Yours may differ.
     
  6. BLACK HORSE

    BLACK HORSE Formula 3
    Silver Subscribed

    Feb 11, 2004
    1,961
    California - Bay Area
    Full Name:
    Rob
    I have a question... I had my started rebuilt, which I reinstalled into the car... so which blade on the solenoid that the white wire coming from the main wire harness attached to???? I took a pic of it prior to removing the starter but its not good and I can't see which blade it is... Can someone circle it on the pic?

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    Rob
     
  7. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,951
    Isle of man- uk
    Is there a circuit between the 2 brass connectors, if there is it will be the 2 connections to the coil and will give an ohms reading. One connection would be the 12 volts from the start signal and the other would be to earth. Does 1 wire show an earth reading
     
  8. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,764
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    #8 Steve Magnusson, Jan 9, 2023
    Last edited: Jan 9, 2023
    The male spade terminal for the white wire coming from the ignition switch Pos III should be labeled "50" on the solenoid.

    The other male spade terminal labeled "15a" is something that goes +12V only when the starter motor is actually cranking (like to fire the cold start injector during starter motor cranking if the TTS is closed).

    Please post the 10-digit Bosch part number that is shown on the solenoid body -- it's not an exotic item and a replacement must be available IMO.
     
  9. BrockBenson

    BrockBenson Formula Junior

    Oct 18, 2018
    277
    Australia
    Hi Steve, that's what I would have thought. Why would Bosch design a unique solenoid for a low volume production car? But I struggled to find a match or suitable cross reference. If you have better luck, please let me know. Picture attached, I think the number reads: 0331 303 082? The second last digit stamping is very light, but it looks like a 8 or could be a 3?

    Thx, BB
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  10. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,764
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    I think this one (WAI 66-9131) has a very good chance of being what you need (it's used on other F models of the same era that have a 50 and 15a terminal):

    https://www.waiglobal.com/us_en/catalogsearch/result/?q=0331303032

    The tricky bit is WAI doesn't sell directly to the public -- you'll need to find a WAI distributor (like maybe an alternator/starter rebuilder). ZM-576 is another manufacturers part number to internet search on:

    https://www.ferrarichat.com/forum/threads/new-starter-solenoid-reference.452906/#post-143214942
     
  11. BrockBenson

    BrockBenson Formula Junior

    Oct 18, 2018
    277
    Australia
  12. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,764
    30°30'40" N 97°35'41" W (Texas)
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    Steve Magnusson
    #12 Steve Magnusson, Jan 9, 2023
    Last edited: Jan 9, 2023
    That is useful document -- just match up what you need. You may actually presently have a "4-terminal" solenoid that you don't need (but it still works fine). If you have no wire to connect to the 15a terminal, you could use the more common "3-terminal" solenoid (something like ZM-578) that only has a male spade terminal 50 (none of the 308QV schematics show a 15a terminal on the starter solenoid). I believe the TR and 308QV starter motors are different, but the starter solenoids are the same/similar beasts
     
  13. BrockBenson

    BrockBenson Formula Junior

    Oct 18, 2018
    277
    Australia
    Correct, my QV had nothing connected to terminal 15a.
    I based the 308/Testarossa starter comment on Superformance showing the same PN for both on their website?
    Maybe originally, they were different but now there is a common unit that fits both? Don't know, never owned or worked on a Testarossa
     
  14. BrockBenson

    BrockBenson Formula Junior

    Oct 18, 2018
    277
    Australia
    Hi All, so this starter solenoid thing has been a real rabbit warren! Lots of solenoids are very close to my original Ferrari (Bosch) unit. There seems to be subtle variations between each in terminal type, orientation, length of battery terminal studs, etc. But the overall dimensions of all this series are very close to my original. My rudimentary drawing and measurements are probably +/- 0.5 to 1mm. So given that, and the physical comparison, I'd say the 308QV Bosch solenoid is ZM 572. And if as Steve mentioned above, that the 308QV doesn't use or need the extra spade terminal, then the ZM 575 is actually correct. I've only owned my car 3 years, so can't be sure the solenoid hasn't been previously replaced. Interestingly Ferrari application is never mentioned for any solenoid! I feel a stealership conspiracy coming on :) If anyone doesn't have any further guidance I'm going to try order a ZM 575 and hope it works! Here is the link to the ZM website and the spec sheets attached below for the two I think are correct. They are exactly the same except one is a single spade and the other a twin spade

    http://www.zm-us.com/

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    Attached Files:

  15. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    6,870
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    Mike 996
    Given the typical use of these cars, I can't figure how they wear out a starter or a starter solenoid! :rolleyes:
     
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  16. ferrariowner

    ferrariowner Formula 3

    Feb 21, 2014
    1,155
    Mansfield, TX
    Full Name:
    Ron
    Mine went bad when the car sat for a long period of time during an overhaul. Don't know why. A local starter shop repaired it for around $35USD. As I recall my gear drive failed.
     
  17. cbmcdona

    cbmcdona Karting
    Silver Subscribed

    Jul 19, 2022
    150
    North Carolina
    Full Name:
    Caleb McDonald
    The solenoid on my 77 GTB was bad. I decided to replace the unit with a smaller gear reduction started from Ferraristarters.com. It cranks a lot faster and starts a lot easier. I kept the old Bosch just for concourse correctness if needed but the newer gear reduction one is better in every way.


    Sent from my iPhone using FerrariChat.com mobile app
     
  18. BrockBenson

    BrockBenson Formula Junior

    Oct 18, 2018
    277
    Australia
    Yes agree. Bosch make quality products. I've got OEM Bosch starters on other cars that are 40 years old and have never needed work! Why not so on a Ferrari application? The starters are mostly the same in design philosophy, just vary to suit application torque requirements and mounting. Maybe on the Ferrari it was under specified, so gets constantly overloaded. Don't know. :)

    I considered one of those, but wondered how long it might last? So many new parts are made in China at a price point which generally involves having to use cheaper materials. Plus I like to keep the car original where I can and enjoy the challenge. But this one has tested my patience :)
     
  19. BrockBenson

    BrockBenson Formula Junior

    Oct 18, 2018
    277
    Australia
    Hi All,
    Just thought I'd close this thread out with a final update. For those that are stubborn and persistent like me, and want to keep their OEM Bosch starter motor, here is the replacement solenoid that was so elusive to find. I'm not sure why Ferrari suppliers don't stock it? This solenoid is for Bosch starter 1 005 821 080 as used in my '84 QV (US). The correct Bosch solenoid for this starter is 0331 303 032 and is NLA.
    Manufacturer ZM in Brazil make replacement ZM 573
    Manufacturer AS-PL in Poland make replacement SS0010
    Supplier Wood Auto in UK sell replacement SND11630
    All are interchangeable (exactly the same). I went with the AS-PL brand because its Euro made and a supplier in NZ had it in stock (so saved lots on shipping).
    Thanks for your input. BB

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  20. Theruse

    Theruse Karting

    Jan 17, 2014
    189
    Maryland
    Full Name:
    Prescott Russo
    I have reviewed many threads on the starter solenoid, but not sure how to remove mine. I removed the rubber cover protecting the solenoid and disconnected the electrical connections. but not sure how to remove solenoid. In the prior photo there is a blade like end on the solenoid.opposite the electrical end. Is this connected to something or can I juast pull out the solenoid? Just don't want to break something if I try to pull out the solenoid.
     
  21. 2dinos

    2dinos F1 Rookie

    Jan 13, 2007
    3,015
    #21 2dinos, Jan 30, 2025
    Last edited: Jan 30, 2025
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    I had a Bosch solenoid problem with the main pull-in winding being open. it was tricky to diagnose because: The solenoid was getting the correct voltage, but the current (only going to ground) was low.

    Going from ancient history memory. The main "pull-in" winding draws ~something like 10 Amps, and the "keeper" winding only draws 2Amps.

    Cool design!
     
  22. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,764
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Yes, the plunger (with the blade like end) is a separate piece from the coil assembly.
     
  23. Theruse

    Theruse Karting

    Jan 17, 2014
    189
    Maryland
    Full Name:
    Prescott Russo
    Explains it all. Very Helpful
     

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