Weird problem - no instruments | FerrariChat

Weird problem - no instruments

Discussion in '456/550/575' started by ferraridriver, Sep 14, 2019.

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  1. ferraridriver

    ferraridriver F1 Rookie

    Aug 8, 2002
    4,134
    Bay Area Calif.
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    Dave
    #1 ferraridriver, Sep 14, 2019
    The situation.....My car, a 2000 550, has set for a month because of a trip abroad, there were no problems before and it has been on a Deltran battery tender.

    The car starts, runs normally, however I have no instruments in the gauge set behind the steering wheel. No tach, speedo, coolant temp, oil pressure, or any of the warning lights like hand brake.

    All of the lights work, turn signals both work and show on panel as do headlights.

    So far I have reconnected the cable connectors to the gauge set, and at the fuse panel.
    The #5 fuse is good.
    The outboard side of the fuse goes to G8, the inboard side goes to J6

    If I supply 12VDC to the #5 fuse everything works as normal so this indicates there is no power (12VDC) being supplied to the instrument panel. If I supply power to just the inboard terminal of fuse #5 everything works so apparently the lack of power at the outboard terminal of fuse #5 is the problem. This terminal is connected to G8 and has good continuity. I need power at G8 which goes to #188 which the manual calls "Cable Multiplying"

    This is where I'm lost, no power to G8/188 and I don't know where that cable goes.
     
  2. ferraridriver

    ferraridriver F1 Rookie

    Aug 8, 2002
    4,134
    Bay Area Calif.
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    Dave
    #2 ferraridriver, Sep 14, 2019
    I may have solved the problem,I have a breadboard fuse panel I bought from Guido Theunissen. It appears there is no continuity between G8 and the outboard side of the #5 fuse. I misspoke above because I was testing a spare fuse panel.
    Tomorrow I'll take the fuse panel out and check for a cold solder joint. Worst case I'll replace it with the original.
     
  3. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    26,367
    socal
    #3 fatbillybob, Sep 14, 2019
    My pegboard style milspec wire soldered fusebox is about 10 years old with no issues. Even the high load cooling fans we talked about getting off the board seem to be fine. Search my old thread on fusebox repair to see what I did. You may want to go that route with the bad fusebox.
     
  4. ferraridriver

    ferraridriver F1 Rookie

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    4,134
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    Dave
    #4 ferraridriver, Sep 14, 2019
    Well, that was the problem, a cold solder joint at the base of the fuse socket.
     
    Qavion likes this.
  5. ferraridriver

    ferraridriver F1 Rookie

    Aug 8, 2002
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    Dave
    #5 ferraridriver, Sep 14, 2019
    Carl, basically this is a similar layout but unfortunately a poor choice of wire I believe.

    I've thought often about your solution, just never had the stomach to carry through. I may give it a lot more thought.
     
  6. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    26,367
    socal
    #6 fatbillybob, Sep 14, 2019
    You are a genius to have found it. My tedious solution was not elegant but has worked.
     
  7. Qavion

    Qavion F1 World Champ
    Silver Subscribed

    Feb 20, 2015
    11,533
    Sydney
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    Ian Riddell
    #7 Qavion, Sep 14, 2019
    "Cable multiplying" is simply wire splices (or sticking multiple wires in one pin or socket).
     
  8. JimEakin

    JimEakin Formula Junior

    Jun 13, 2015
    988
    Mountain Living
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    Jim
    #8 JimEakin, Sep 16, 2019
    I installed off-board relays for the cooling fans over a year ago. Solved the overheating issues that I had. Someday (soon) I'll post the wiring and parts I used. John Cribb @Cribbj pointed out that the SPAL fans use metric-280 connectors, so no Ferrari tax on the parts. The installation is completely reversible.
     
    F456M likes this.
  9. Cribbj

    Cribbj Formula 3

    Jan 1, 2011
    2,295
    Cooke City MT, The Coolest Small Town in America
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    John
    #9 Cribbj, Sep 17, 2019
    Jim I'm curious to know which off-board relays (rating/style/mounting) you used for the fans and if they're showing any signs of overheating at the sockets? Those fans suck a LOT of current for a couple hundred milliseconds whenever they switch on - nearly 3x or 4x their running current, IIRC, and on other cars I've seen under spec'd relay sockets actually melt from this starting current.
     
  10. JimEakin

    JimEakin Formula Junior

    Jun 13, 2015
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    Mountain Living
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    Jim
    #10 JimEakin, Sep 17, 2019
    John, next time I'm under the car with cover off I'll inspect them. i recall using relays that were spec'd at 40A, but I did not consider inrush current ratings.

    This is also another consideration why the fan relays should be moved off the original switch/relay board.
     
    F456M likes this.
  11. scowman

    scowman Formula 3

    Mar 25, 2014
    2,498
    Scottsdale AZ
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    Stu Boogie
    #11 scowman, Sep 19, 2019
    +1. I replaced fans and added relays for both in the front end. Pulled the wire off alternator with in line fuses. Easy job.
     
  12. scowman

    scowman Formula 3

    Mar 25, 2014
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    Stu Boogie
    #12 scowman, Sep 19, 2019
    F456M likes this.
  13. F456M

    F456M F1 Rookie

    Jan 8, 2010
    3,665
    Oslo
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    Erik
    #13 F456M, Sep 22, 2019
    Very interesting. I want to do the same. Do you still use the old relays to activate your new relays? My idea is to install two small (not so bright) LED indicators in the coolant temp gauge so that when the fan get power (power on the output pin of the last relay), the LED is lit. That way, if any of the four relays does not work, you will see that there is only one yellow LED on. And maybe also a timer and a button, so that the cooling fans can run two minutes after you turn off the engine. That would make the engine compartment and AC condenser much colder before next start up.
     
  14. scowman

    scowman Formula 3

    Mar 25, 2014
    2,498
    Scottsdale AZ
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    Stu Boogie
    #14 scowman, Sep 22, 2019
    Yes. Old relays still in use but only carrying signal load. I watch my warm up temps pretty close and you can hear the fan kick in too.
     

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