328 Instrument Cluster and Console Lights | FerrariChat
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328 Instrument Cluster and Console Lights

Discussion in 'Technical Q&A' started by 4REEE, Jan 28, 2007.

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  1. 4REEE

    4REEE Rookie

    Jan 28, 2007
    11
    Dayton, Tennessee
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    Thomas E. Rodgers
    #1 4REEE, Jan 28, 2007
    Hi!

    I have an '86 328 GTS that has intermittent instrument cluster and panel lights. Most of the time they are off and won't come on. I have power at the fuse block (fuse 21) but no lights. I was thinking that the panel illumination rheostat might be the culprit, but am not sure how to remove it to check it out. Any ideas on the lack of panel/console lights and its resolution would be greatly appreciated - thanks!!!
     
  2. f355spider

    f355spider F1 World Champ
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    #2 f355spider, Jan 28, 2007
    Switch is easy to remove....I am only guessing (it has been a few years since I had my 328) but I seem to recall you can reach it from behind and gently push forward and out. Easiest thing to do, (and will brighten your instrument lights to boot) is to make a jumper with some spade connectors and just bypass that reostat! I did.
     
  3. 4REEE

    4REEE Rookie

    Jan 28, 2007
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    Dayton, Tennessee
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    Thomas E. Rodgers
    #3 4REEE, Jan 28, 2007
    Hi Dave!

    I appreciate the quick response - I'll give it a shot and let you know how I make out. Also enjoyed your quote!!!

    Tom
     
  4. 4REEE

    4REEE Rookie

    Jan 28, 2007
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    Dayton, Tennessee
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    Thomas E. Rodgers
    #4 4REEE, Jan 28, 2007
    I pulled off the connector from the back of the dimmer rheostat - there are 3 wires - black, yellow, and white. I'm guessing to jumper the yellow and white???
     
  5. miketuason

    miketuason F1 World Champ
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    #5 miketuason, Jan 28, 2007
    Just to make sure use a test light to know for sure which is gound and 12v
     
  6. 4REEE

    4REEE Rookie

    Jan 28, 2007
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    Dayton, Tennessee
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    Thomas E. Rodgers
    #6 4REEE, Jan 28, 2007
    Didn't get 12 volts anywhere on that connector between any of the wires. Guess that I'll have to start working my way back towards the fuse block. Might be a connector coming off of the fuse block that is loose or broken?
     
  7. miketuason

    miketuason F1 World Champ
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    #7 miketuason, Jan 28, 2007
    I think you will only get 12v if you turn the ignition on and/or turn the headlight switch on.
     
  8. 4REEE

    4REEE Rookie

    Jan 28, 2007
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    Dayton, Tennessee
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    Thomas E. Rodgers
    #8 4REEE, Jan 29, 2007
    That's what I did and no voltage to be found - I'll keep looking - thanks!!!
     
  9. f355spider

    f355spider F1 World Champ
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    #9 f355spider, Jan 29, 2007
    I forget the order, but one is ground, one is for the switch illumination, and the other is dimming the instrument lighting.
     
  10. Mike328

    Mike328 F1 Rookie

    Oct 19, 2002
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    #10 Mike328, Jan 29, 2007
    Hmm... We may be saying the same thing... Or I may be wrong, but...

    I thought there was ground, then full 12V INPUT into the rheostat, then the diminished (dimmed) less-than-or-equal-to 12V OUTPUT from the rheostat that is then the source current for all lights that are dimmed, including the speedo lights, other gauge lights, etc.

    Tom, you should be looking at all of this in the wiring diagram for the 328. It tells you explicity what is what including color codes.

    http://ferrari.jenkins.org/books/
    You want the 1989 Ferrari 328 Wiring Diagram.
     
  11. f355spider

    f355spider F1 World Champ
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    #11 f355spider, Jan 29, 2007
    Yes! You are right!!!! Black is ground, one is 12v input, and the dimmed voltage out! Stupid me! :(
     
  12. docweed

    docweed Formula Junior

    Dec 8, 2004
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    Chuck Stewart
    #12 docweed, Jan 29, 2007
    Did you try spraying contact cleaner or WD-40 in the switch first?? Might help.
     

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