Electrical Experts - Help Please | FerrariChat

Electrical Experts - Help Please

Discussion in 'Technical Q&A' started by fchip, Oct 30, 2010.

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  1. fchip

    fchip Formula Junior

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    Chip G
    I just bought Paul's great wiring diagrams for my 84 US 308QV. They show connections on the tops of number 1, 2, 3, 5, 6, and 7 fuses. Yet, as you can see from the photos below my original wiring had connections at 2,3,4,5,6,7 fuses. When I did the Birdman upgrade I simply replicated the original wiring. Since I am still struggling with some low beam headlight issues I wonder if this discrepancy could be a contributor. What do the experts say? Apologies for the slow learning curve, but I am getting there inch by inch. Thanks.
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    Last edited by a moderator: Sep 7, 2017
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ Lifetime Rossa

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    You should match the wire colors/locations as shown on Paul's diagram (at both the top and bottom of the fuses) and make sure that you have the the LH fuseblock and the RH fuseblock in the correct places -- they are not identical! Your wire connections at the top of the fuses are definitely not stock for the RH fuse block (but it should not cause any problem with the basic operation of the headlights -- only how the headlight flashing function works). Stock would be:

    1 (leftmost of the RH fuseblock) = red

    2 = light blue

    3 = yellow

    4 = not used

    5 = light blue

    6 = green

    7 = red

    8 = not used

    9 (rightmost of the RH fuseblock) = not used

    The tops of various fuses are connected together by the fuseblock itself (1-to-2, 3-to-4, 5-to-6, and 7-to-8-to-9 -- and this is how you would identify the RH fuseblock as being for the RH side) so, for example, putting the yellow wire onto the top of fuse #4 instead of fuse #3 would be fine, or having the red wire on fuse #2 instead of fuse #1 is equivalent, etc., but your connections to 1, 2, and 3 are definitely non-stock and would result in the following behavior:

    parking lights "on" and pull stalk to flash = low beams flash
    low beams "on" and pull stalk to flash = nothing (low beams just "on" constantly)
    high beams "on" and pull stalk to flash = low beams flash (and high beams "on" constantly)

    the stock behavior would be:

    parking lights "on" and pull stalk to flash = high beams flash
    low beams "on" and pull stalk to flash = high beams flash (low beams "on" constantly)
    high beams "on" and pull stalk to flash = nothing (high beams just "on" constantly)

    To debug any basic headlight problem(s), I'd suggest that you confirm/deny these various things as the starting point of the investigation:

    1 (leftmost of the RH fuseblock) = red = this wire should be +12V (relative to ground) only when the stalk knob is rotated to "on" and the stalk is in the high beam position

    3 = yellow = this wire should be +12V (relative to ground) only when the stalk knob is rotated to "on" and the stalk is in the low beam position

    6 = green = this wire should be +12V (relative to ground) whenever the stalk knob is rotated to "on" (regardless of stalk position)

    7 = red = always +12V (relative to ground) - even with the key "off"

    Good Hunting!
     
    Last edited: Oct 30, 2010
  3. Paul_308

    Paul_308 Formula 3

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    Since you've only downloaded the US QV diagram (I keep track), return to download the functional 308 diagrams, especially the two marked 'headlights & lift motors' and 'mods using relays'. It will help you focus on the headlight circuit.

    You really need to measure the voltage at the fuses and at the headlights to assess the problem. And don't overlook voltage lost at the headlight ground. I was disturbed to find a between battery and headlights, a 2.7 volt drop, due to the switch and the long small gauge wiring. My answer was adding relays at the headlights so the battery voltage goes directly to the headlights.

    With the relay mod, the cars headlight switch now only serves to turn the relay on, helping save the delicate and expensive switch. Doing the relay mod, I have an amazing brightness now without increasing lamp wattage which others have done. Daniel Stern has a kit for this or use the abundance of information on diy the mod yourself. With the DS mod you still have to do half the wiring anyway but he furnishes the relays.
    http://www.danielsternlighting.com/products/products.html Note a recent user reported instructions on low beam relay may have an error.

    ___________________________
    http://www.FerrariDiagrams.com
     
  4. fchip

    fchip Formula Junior

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    Thanks Steve.
    I redid the top wires to the right hand fuse box to match Paul's diagram and your description. Then I checked the circuits as you suggested above. All are correct EXCEPT that the 3 fuse does show +12v when the stalk is in the low position, but nothing when the stalk is in the off position (ie. no "continuity light) on my circuit tester. I assume that means that things are now OK at the fuse box and somewhere downstream I have a break due to incorrect wiring or a faulty wire. Makes sense?
     
  5. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ Lifetime Rossa

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    Don't really follow your "EXCEPT" description here -- if the top of fuse #3 is +12V when the stalk knob is rotated "on" and the stalk lever is in the low beam position, that is how it should be. If your "continuity tester" (when things are "off") is indicating that from the top of fuse #3 -to- the low beam bulbs -to- ground is no continuity, that would be a problem.

    You never described your problem in this thread, but, if the top of fuse #3 is at +12V, and the low beams are not "on", then you must have a problem downstream of the fuseblock, or in the fuseblock itself. When the top of fuse #3 is at +12V are the bottoms of fuses #3 and #4 also at +12V (they should be)?
     
    Last edited: Nov 1, 2010
  6. fchip

    fchip Formula Junior

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    I am getting no "clicking" sound at the relays which tells me that they are not receiving voltage when I move the stalk to the low beam or the high beam setting. These are the low beam and high beam relays I installed with the Daniel Stern upgrade. Would that be related to my issue with the 3 and 4 fuses?
     
  7. Dino246gt

    Dino246gt Formula 3

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    MY problem is that the LEFT turnsignal works fine, until I turn the heater FAN on, then it clicks rapidly until I turn the fan off. Everything else works fine, what could cause that? (1982 308GTBi)
     
  8. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ Lifetime Rossa

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    If the bottoms of fuses #3 and #4 in the RH fuseblock go to +12V when you rotate the stalk knob "on" and have the stalk in the low beam position, but your added D.S. relay(s?) for the low beams doesn't "click" on, then (I believe) you don't have it hooked up correctly -- i.e., in the stock configuration the +12V at the bottom of fuses #3 and #4 directly runs the low beam filaments; in the D.S. setup, the +12V from the bottom of fuses #3 and #4 are used to close a relay which then puts +12V from the battery onto the low beam filaments.

    Likewise, if the bottom of fuses #1 and #2 in the RH fuseblock go to +12V when you rotate the stalk knob "on" and have the stalk in the high beam position, but your added D.S. relay(s?) for the high beams doesn't "click" on, then (I believe) you don't have it hooked up correctly -- same blah...blah...blah...(except for the high beam filaments)

    Can you post a scan of the D.S. schematic?
     
    Last edited: Nov 1, 2010
  9. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ Lifetime Rossa

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    The LH heater fan blower motor and the LH front turn signal share a common ground connection to the chassis. Most likely your problem is related to this ground connection not being in good condition -- IMO you should find and clean/reseat these common ground connections.
     
  10. fchip

    fchip Formula Junior

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    Thanks, that makes sense. I will check it out.
     
  11. 335s

    335s Formula Junior

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    My head huts...and I know what I'm doing...
    Great fix, fellas, for a real problemn area!
     

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