Mondial bulb-failure indicator | FerrariChat

Mondial bulb-failure indicator

Discussion in 'Technical Q&A' started by KKSBA, Dec 22, 2003.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. KKSBA

    KKSBA F1 World Champ
    Rossa Subscribed

    Oct 31, 2003
    14,930
    SBarbara-La Jolla CA
    Full Name:
    KKSBA
    1985 Mondial QV Cabriolet:

    This (and other pre 1987/86?) Mondials have an indicator panel next to the shifter with various indicator lights for engine oil/transmission oil/open hood etc.

    One of the lights (a yellow one) is supposed to indicate a bulb-failure. The problem is when ever the lights are on, the bulb-failure indicator is on.

    All bulbs have been checked and all are ok. They have been swapped from side to side and with new ones.

    The indicator lights when the headlights are turned on, which turns on stop lights, four marker lights, and front parking lights.

    Interestingly, the bulb-failure also turns on when just the parking light switch is enabled (ie main headlights are not on, just front two parking lights and two rear stop lights).

    This makes one suspect the problem is either with the two front parking lights or two read stop lights only, or of course the actual indicator panel.

    Does anyone know specifically how this circuit works (don't have access to an 85 QV mondial wiring diagramm, does anyone know where to download on the net?).

    In reading about various Jaguar, and Volvo systems, the indicator tests for a similar current draw from bulbs on the right & left side. If one is out of whack (drawing too little) then the indicator lights. On some other cars the bulbs are wired right/left to a bimetallic strip that heats up with current draw, if one side takes too little the metal "swings" towards that side making contact and lighting the indicator. Another similar system uses a reed switch with two opposing magnetic fields driven by the current draw of the right/left side bulbs. Does anyone know what kind of system the Mondial employs for this?

    The resistance to ground on the light sockets is nominal about 0.2 ohms. The voltage on the light sockets is the same. The bulbs have been swapped with new ones.

    This failure was inherited so their was no moment of change that was noticed.

    Any ideas appreciated!
     
  2. 4rebob

    4rebob Karting

    Nov 3, 2003
    175
    Eagle River, Alaska
    Full Name:
    Robert Taylor
    Have you check the license plate lights? Also, check to see it the bulbs match what the book says they should be. Mine had front parking bulbs that worked, but were not the correct ones. I put the correct ones in, and the warning light went out. And there are 2 bulbs in each tail light.
     
  3. KKSBA

    KKSBA F1 World Champ
    Rossa Subscribed

    Oct 31, 2003
    14,930
    SBarbara-La Jolla CA
    Full Name:
    KKSBA
    I found one of the license plate bulbs burned out. So I replaced them both. The book says type 67 so thats what I put in there.

    The front parking lights (and rear tail lights) are supposed to be type 1034 and I checked those.

    Anyone with a QV Mondial: If you turn on the parking switch on the center console, the P lights up on the dash cluster, but the yellow warning light on the indicator panel doesn't light up, right?

    If it doesn't it will help me narrow the problem down to only four bulbs and four sets of wires. If it does as a reminder, then I have a lot more to check. I wouldn't think this is the way it would be, but just double checking since I don't have a wiring diagram to verify against.
     
  4. KKSBA

    KKSBA F1 World Champ
    Rossa Subscribed

    Oct 31, 2003
    14,930
    SBarbara-La Jolla CA
    Full Name:
    KKSBA
    Thanks, I'll check the 2nd bulb in the tail light assembly. There are actually three bulbs two facing the rear of the car and another facing forward. Maybe it has something to do with hazard flashers or turn signal.
     
  5. Ron

    Ron Formula Junior

    Dec 23, 2002
    926
    LA
    I had the same annoying problem when I had my Mondial. It finally was solved by replacing the license plate lights.

    I hope your fix turns out as easy. If you are satisfied that all the lights work and it is a faulty indication, I would disable the warning light.
     
  6. 4rebob

    4rebob Karting

    Nov 3, 2003
    175
    Eagle River, Alaska
    Full Name:
    Robert Taylor
    The ones facing forward are the interior trunk lights, on all the time when the parking lights are on.

    Anyone with a QV Mondial: If you turn on the parking switch on the center console, the P lights up on the dash cluster, but the yellow warning light on the indicator panel doesn't light up, right?

    I think so. I'll check tonight.

    The wiring diagram for my 83 was about $10.
     
  7. KKSBA

    KKSBA F1 World Champ
    Rossa Subscribed

    Oct 31, 2003
    14,930
    SBarbara-La Jolla CA
    Full Name:
    KKSBA
    Thanks for checking it out for me. Yeah, it's not a cost thing, it is an instant gratification thing! lol! The Internet is the mecca of instant gratification!

    I'll order the schematics if I can't figure this bugger out after a few more days..
     
  8. 4rebob

    4rebob Karting

    Nov 3, 2003
    175
    Eagle River, Alaska
    Full Name:
    Robert Taylor
    On my 83 Mondial QV Cab:

    Console parking light switch ON, ignition key OFF = green dash “P” ON, 2 front white parking lights ON, 2 rear red parking lights ON (upper 2 bulbs only).

    Console parking light switch ON, ignition key ON = green dash “P” ON, 2 front white parking lights ON, 2 rear red parking lights ON (upper 2 bulbs only), orange warning light ON. (I think it’s telling you not to drive around with the parking lights on.)

    Stalk switch rotated ON, Stalk all the way up = green dash “lights on” ON, 2 front white parking lights ON, head lights DOWN and OFF, four side marker lights ON, 2 rear red parking lights ON (all 4 bulbs), 2 license plate lights ON, 2 trunk lights ON.

    Stalk switch rotated ON, Stalk in the middle (down on notch) = green dash “lights on” ON, 2 front white parking lights ON, head lights UP and 2 low beams ON, four side marker lights ON, 2 rear red parking lights ON (all 4 bulbs), 2 license plate lights ON, 2 trunk lights ON.

    Stalk switch rotated ON, Stalk all the way down = green dash “lights on” ON, 2 front white parking lights ON, head lights UP and 2 low beams ON and 2 high beams ON, four side marker lights ON, 2 rear red parking lights ON (all 4 bulbs), 2 license plate lights ON, 2 trunk lights ON.

    Stalk switch rotated OFF in any stalk position (up, middle, down) = all lights OFF.

    Stalk light control is unaffected by the ignition switch.

    Fog lights can be turned ON only when the stalk switch is rotated ON.

    Anyone with a QV Mondial: If you turn on the parking switch on the center console, the P lights up on the dash cluster, but the yellow warning light on the indicator panel doesn't light up, right? Yes and No, it dependes on the ignition switch, ignition ON = warning, ignition OFF = OK.

    I think that’s how it works...
     
  9. KKSBA

    KKSBA F1 World Champ
    Rossa Subscribed

    Oct 31, 2003
    14,930
    SBarbara-La Jolla CA
    Full Name:
    KKSBA
    Thanks a ton for the info. I will check against mine. This helps a tremendous amount!
     
  10. 4rebob

    4rebob Karting

    Nov 3, 2003
    175
    Eagle River, Alaska
    Full Name:
    Robert Taylor
    ... try pulling the stalk toward the steering wheel to “flash to pass”...

    Stalk switch rotated OFF in any stalk position (up, middle, down) = flashes the fog lights.

    Stalk switch rotated ON, Stalk all the way up (parking lights) = flashes the fog lights.

    Stalk switch rotated ON, Stalk in the middle (low beam driving lights) = flashes the high beams.

    Stalk switch rotated ON, Stalk all the way down (high beam driving lights) = does nothing.
     
  11. norm

    norm Karting

    May 30, 2003
    204
    Rochester, NY
    I recently sold my '84 Mondial QV cab. I have a Factory service manual for sale( the big blue one!), if you are interested.
     

Share This Page