F355 Spider - Seat Problem! | Page 2 | FerrariChat

F355 Spider - Seat Problem!

Discussion in 'Technical Q&A' started by Dem, Jun 12, 2004.

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  1. f355spider

    f355spider F1 World Champ
    Owner Rossa Subscribed

    May 29, 2001
    17,913
    USA
    Okay, this thread is a "keeper" and should go in the "parts & service" section. I can see this saving 355 spider owners thousands! Good show!
     
  2. Merdav

    Merdav Formula Junior

    Apr 11, 2004
    980
    Way to go Jim, I can relate to exaclty what you saw inside that pot, crappy design isn't it? So was anything actually broken inside or was the little white ball joint just constantly slipping not allowing the pot to turn at all? That was the case with mine, I just put a little 3in1 oil on the pot contact, and filed a little off the shaft that sat in the middle of it. Mine spun fine until I put the shaft in place, the shaft was a hair too tight and kept the pot from spinning so filing a little off kept it from expanding when in place and it worked perfect! Than on the ball part I just sprayed a little Windex on it to remove ANY oils, blew it clean with compressed air for better friction, better than new!
     
  3. Michael,

    There seems to be two problems with the position sensors. The first is that the white plastic socket prongs become brittle and simply break off. Mine had one prong broken and with a light squeeze all of them broke off. The feel of the new socket from the Jag part felt much more solid- even though it looked just the same. Perhaps it will fail eventually as well. Needless to say, the reason mine failed was due to the break, and it simply spun free on the ball end that drives the potentiometer. It seemed as though the plastic material was disintigrating.

    The second issue was the potentiometer itself. Like yours, mine was a bit stiff. I used a very small amount of light oil- and I mean A SMALL AMOUNT on each side of the mating surfaces of the potentiometer. After a few rotations, it moved smoothly.

    I did notice that when the black drive shaft was inserted into the potentiometer, that the potentiometer bound slightly. Even though this went away after applying the oil, I also trimmed up the shaft a tad so that the fit into the potentiometer was correct. I was surprised to hear that yours did the same thing!!!

    So, here are some photos for the folks who may not have seen the part.
     
  4. Merdav

    Merdav Formula Junior

    Apr 11, 2004
    980
    Good photos Jim, typical that the crappy design failures are so consistant.
    You really did good research on this and I'm sure this thread is going to be searched back to for many years to come.
     
  5. Dave_Car_Guy

    Dave_Car_Guy Karting

    Apr 24, 2004
    130
    Northern California
    Full Name:
    Dave
    Amazing...I was told by the dealer that the potentiometer part alone was something like $600. Seeing your photos with this great thread make me realize that this is indeed another simple part with a better fix than paying exhorbitant dealership prices! Thanks all
     
  6. Dem

    Dem Formula 3

    Mar 21, 2004
    1,027
    London
    Full Name:
    Dem
    #31 Dem, Aug 1, 2004
    Last edited by a moderator: Sep 7, 2017
    Hi all !

    Just one last thing to add! As I mentioned, at the start of the thread, not only has the electrical mechanism given up, but so had the mechanical 'flip' for the seat back. Well, I got to the bottom of the mechanical bit today, so for future reference, in case anyone suffers from this, it was quite easy to find the problem in the end!

    I did some investigation (i.e. took the lever off!) and it revealed the problem! Looks like there is a 'split pin' or something similar which acts as a pivot in part of the mechanism (joining two metal links). This 'split pin' is now missing (I presume broken, fallen out, and somewhere on the carpet). I've attached a picture below showing exactly where this pivot point is. For now, I have simply bent a thin piece of steel rod through this pivot point to hold it together and this has made a reasonable temporary fix! But who knows how long for.........!!!!???!?!? However, I would like to fix this properly of course, and have asked the guys who sold me the car if this 'split pin' can be obtained.

    Something which may or may not be related, is a broken locking washer which I found on the carpet under the hinge mechanism for the seat. When I was checking out the passenger seat (which works fine) as a comparison to the broken driver's seat, I also found an indentical broken washer on the carpet! Not sure if the discovery of these washers is related to the driver's seat problem, as the passenger seat still flips backwards / forwards fine).

    Anyway, this is just for future information and hopefully useful to someone else! Thanks to everyone else on this thread regarding potentiometer info!

    Cheers,

    Dem.
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  7. FL 355

    FL 355 Formula 3

    Nov 3, 2002
    1,665
    Ft Laud
    Full Name:
    Frank Lipinski
    Excellent post. I'll throw one more option into the mix. You can wire the emergency switch directly to the center consol normal switch.

    Takes 15 minutes. Your roof will operate without the seats moving / windows / parking brake / etc. No need to worry about potentiometers.

    However, you must make sure seats are forward enough for roof to clear.

    I'm short enough where the roof operates with plenty of clearance in my normal driving position. Also much faster operation if you're in a hurry.
     
  8. Dem

    Dem Formula 3

    Mar 21, 2004
    1,027
    London
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    Dem
    OK - my last word on this subject! My only concern is if my lever mechanism breaks again and leaves me stranded with the roof down and no way of moving the seat. I think someone mentioned that simply wiring the seat motor (black connector) to +12V would activate it (reversing the wires would move the seat the other way). I was thinking about making up a link lead which would plug into the seat motor one end and then into the cigarette lighter on the other (a handy emergency tool to keep in the car!). Any ideas if the current drawn by the seat motor would be OK for the cigarette lighter, or is likely to be too much?

    Cheers and goodnight!

    Dem.
     
  9. cgperry

    cgperry Formula Junior
    Rossa Subscribed

    Nov 2, 2003
    506
    Chas SC
    Full Name:
    Charles Perry
    This is a fantastic thread and I've used everything on it, so I'll add my two cents for things to watch for.

    First, on repairing the seatback angle adjuster. To get to it, you take an allen head screw out of the handle itself (on the axis). Then remove the two small phillips head screws holding the seat pocket on the back of the seat. This will allow the big trim piece to pull away and you can see the lock and release mechanism. In my case, the little pin mentioned above was fine, but the three allen head screws which hold the release mechanism to the seat frame were loose (well, 2 loose, 1 gone entirely) so the teeth weren't engaging. Re-tightening the loose ones fixed the problem, and I'll try to order the missing one.

    Secondly, when repairing the seat potentiometers above, be careful when you re-bolt the seat to the floor when you're done. On the rear two bolts, there is a silver rectangular shaped washer under each one. This washer MUST be aligned longitudinally (with the rounded edges facing the front and back of the car). If you install it transversely or if it rotates too much when you are re-tightening the seat bolts, the washer will block the seat when it moves back. This can look like the potentiometer isn't fixed or there are other problems.

    Other than that, this is great info which probably saved me $1000 in the last week.
     
  10. richard_wallace

    richard_wallace Formula 3

    Feb 6, 2004
    1,956
    Cincinnati, Ohio
    Full Name:
    Richard Wallace
    Frank - this is a good point - and I did the same thing a long while back after my 3rd seat issue, etc. This, I think is the way to go - with the whole mechinism - you really are not in the driving position in car when you are putting the top down (or at least I wasn't due to leg room) - so you will not forget to put the seats up - since you are parked - emergency brake up and doors open. This way will ensure that if your seat mechinism does not work - you are not fumbling in a rain situation or in a hurry getting the top up - this will eliminate that concern. It should be noted - the windows will not go down either if you do the bypass either - so you should have the windows down slightly when putting the top back up.

    As Frank and I have talked - if the motor on my top goes out again (I am on the 3rd one) - I am going to make it a manual top like on the 348. I really think the 355 should have had a manual top to begin with - there is really no advantage to it being electric - The car is small, the top does not fold down in the back (like the 360), the car cannot be moving with putting the top up or down, emergency break on, etc. just hard to figure out why they made it electric. (honestly my biggest grip on the 355 is the top).
     
  11. GLENNB

    GLENNB Rookie

    Jun 16, 2005
    4
    I JUST FINISHED A 97 355 SPIDER THAT HAD THAT PROBLEM AND FOUND IF YOU PUT A TEST LIGHT ON THE WHITE PLUG AND TOUCH THE GREY WIRE IT WILL MOVE THE SEAT FORWARD

    GLENN
     
  12. RedF355

    RedF355 Karting

    Mar 1, 2004
    56
    Seymour, Indiana
    Full Name:
    Todd
    I maybe new here, and cannot help you with your seat, other than the wiring diagram or something, but the real question is you let your girlfriend drive it????? Bad Idea....!! Laughing.... I think mine just learned to spell the 355 part.... LOL. if diagrams would help, I have them.


    Have a great day!
     
  13. cgperry

    cgperry Formula Junior
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    Nov 2, 2003
    506
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    Charles Perry
    My passenger side quit again and this time the socket on the pot clutch is broken. I'm interested in getting the Jaguar part (which I see from above is part #JLM21117) and swapping the clutch into my Ferrari gears. I do have two questions which hopefully someone remembers the answer to since this is an old thread:

    1) Does anyone know which model and year that Jaguar part # is from? Sometimes having the part# isn't enough if you get a parts monkey that can only search by your car's model and year.

    2) At the bottom of the clutch socket (where the ball from the gear clicks in), there's a little lock ring which I assume keeps some pressure on the ball to keep the clutch from slipping until the potentiometer hits full rotation one way or the other. I'm assuming I'll have to take the socket part off the Jaguar gear and transfer it to the Ferrari gear, but the plastic looks too brittle to just pull the ball out without breaking the new socket, and the ring is so tiny that my normal lock-ring pliers won't fit inside it. For those who've done the switch, how did you get the socket off the Jaguar gear without stressing or breaking the little legs?

    Thanks!
     
  14. CJPerry: Experience has shown that there are two problems with the position sensors. The first is that the potentiometer materials swell and cause the pot to actually become hard to turn. The second is that the plastic used in the clutch becomes brittle and breaks. You can replace the clutch parts using those from the Jag part, but the Jag part has a different ohm value potentiometer and the drive gear set has a different ratio. My suggestion is to use the plastic clutch parts from the Jag part and then try to source a new potentiometer from Bourns or other potentiometer mfgs. You must then unsolder the old part and replace with the new- very easy. After you do the work and replace the seat back into the car, you should seek out someone with an Ferrari SDI computer. There is a routine in the SD1 that runs the seats forward and backward and works with the user to re-learn the fore and aft postions of your seats and get the top computer back into alignment for normal operation. Good luck. -Jim
     
  15. CG: To answer your question, you should not simply pull the socket from the ball. The small steel ring will easily pull downward which will free the plastic prongs of the socket which will allow you to pull the socket from the ball. Just use your fingernails to pull the ring downward. If the socket is in good shape, this will work. If the socken has become brittle, you are out of luck- and it should be replaced anyway. -J
     
  16. steve f

    steve f F1 World Champ

    Mar 15, 2004
    12,119
    12cylinder town
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    steve
    wow somebody has been trawling the archives
     
  17. 1badboy

    1badboy Formula Junior

    Dec 11, 2004
    290
    Hermosa Beach, CA
    Full Name:
    Eric Rayl
    I would suggest being VERY careful if you carry coins in your pocket- one slips out and under the seat and gets caught in the seat rail and you are in trouble. It cost almost $300 to get fixed due to labor involved.

    Just my two cents...

    Eric
     
  18. cgperry

    cgperry Formula Junior
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    Nov 2, 2003
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    Charles Perry
    JimC - Thanks for the information; looks good. From my limited testing with an ohmmeter, it appears that the pot itself is an audio-taper pot, not a linear-taper pot. Does this mesh with what you recall? Ordering a replacement shouldn't be hard, but getting the right taper is crucial.
     
  19. CG: The potentiometer is linear. There is nothing special about it. The only trick is to purchase the version that has the same resistance and the same physical design. Once you have the seat position sensor removed from the car, you can split the halves and the parts will be visible. Snap a digital photo of the potentiometer and contact Bourns or other potentiometer manufacturer and you will probably find that the part is under $5. One of these days I'm going to do this search so I can tell people what part number to buy.

    CG: Don't make too much out of this device. There is nothing critical here. With the little clutch arrangment, it even sets itself after install- because the clutch slips when the pot has reached it's endpoint and the seat is still sliding forward or aft. Just replace the clutch and the pot, install, and find someone with an SDI. The SDI program then asks you to run the seats all the way forward and acknowledge, then all the way back and acknowledge, and after a few other actions, you are good to go. The danger of using the Jag part is that the gear ratio is way wrong and the pot is a different value. I cannot imagine how this would work becuase the pot would swipe it's range in a much shorter sweep of the seat. There may be other Jag parts that are identical to the Ferrari part, but probably not. As I recall, the gear sets are color coded and the color of the two gears in the Jag part are different than the ferrari part. The housings and circuit boards are identical though- except for the pot value soldered to the small board.
     
  20. cgperry

    cgperry Formula Junior
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    Nov 2, 2003
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    Charles Perry
    I bought one of the Jag parts and the pot in that one was 4.3kohm. My Ferrari part read 4.7kohms. Since 400 ohms difference is less than 10% (which is within tolerance ranges for some cheap parts), I decided as an experiment to rebuild my Ferrari seat sensor with two parts from the Jag sensor - the clutch and the actual potentiometer itself. I basically just unsoldered the wires from the Ferrari circuit board and soldered them into the Jag board (since my Ferrari pot was binding badly when the clutch shaft was inserted). Then I moved the Jag clutch to the Ferrari gears and reassembled the part.

    Installed it this morning and it works perfectly.

    Of course, the Jag part was $196 at my local dealer - not the $100 someone else posted. Rutlands lists the Ferrari part for $190 and Ricambi has it for $260. So using the Jag parts doesn't really save you money for the moment. Perhaps it will when the Ferrari part is no longer available. The clutch plastic on the Jag part was much more translucent than on the Ferrari part. I don't know whether it's a better/more flexible grade of plastic, but if so that would help prevent one of the failures of the Ferrari part.

    As a side note, it did not work right off when I installed it. I had to turn the car's battery cutoff switch off for a few minutes. When I turned it back on it worked fine. Perhaps there's some code in the convertible top's ECU that kept it from letting the seat move.
     
  21. Aeroengineman

    Aeroengineman Formula Junior

    Oct 5, 2003
    897
    Maple Valley, WA
    Full Name:
    Dave Tegeler
    I can find the Top up-down emergency switch and out my top down but supposedly there is a seat position override switch in the center console I cannot find. I need to move the seats to remove the 4 bolts to replace the seat Potentiometer

    Help Please!
     
  22. gothspeed

    gothspeed F1 World Champ

    May 26, 2006
    10,244
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    goth
    Are you using the OEM pots for replacement?
     
  23. 2NA

    2NA F1 World Champ
    Consultant Owner Professional Ferrari Technician

    Dec 29, 2006
    18,214
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    Tim Keseluk
    If the seat won't move because the motor has failed you will likely have to get creative as at least two bolts will have seat in the way.
     
  24. tonyh

    tonyh F1 World Champ
    Lifetime Rossa Owner

    Dec 23, 2002
    14,372
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    Tony H
    http://www.ferrarichat.com/forum/showthread.php?t=69546&highlight=roof

    section H2 controls ,page 33 of owners' PDF shows manual close procedure

    http://homepages.nildram.co.uk/~richmet/docs/MUM_capH2_F355BerlinettaGtsSpider.pdf
     
  25. Aeroengineman

    Aeroengineman Formula Junior

    Oct 5, 2003
    897
    Maple Valley, WA
    Full Name:
    Dave Tegeler
    See my posting on 348/355 - I moved the seats by disconnecting the White potentiometer Connector and operating the seats with the normal switches.
     

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