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Interior light problem

Discussion in 'Technical Q&A' started by rickjaffe, Mar 26, 2005.

  1. rickjaffe

    rickjaffe Formula Junior

    Mar 6, 2005
    362
    houston
    Full Name:
    richard jaffe
    #1 rickjaffe, Mar 26, 2005
    Last edited by a moderator: Sep 7, 2017
    the three interior lights in my 308 gt4 do not work, and I'm going to try to troubleshoot it.

    first, everything else works (panel lights, clock antenna switch, etc) and I remember that the interior lights are on the same fuse as some of the other lights. If so then I don't think I have a fuse problem. is that correct?


    I thought the obvious first step is to make sure the bulbs are good, since I just bought the car and who knows if one bulb went after another way back with some prior owner.

    here is a picture of my pass side interior light panel. I was thinking of just placing a screw driver in trying to pop the housing out? is that ok or do I have to take out the whole door panel (which I'm alittle reluctant to do?

    I've got a couple of bulbs in a round plastic box in the jack kit, which I thought I'd try (don't know if that's part of the jack kit or an aftermarket type deal)

    assuming the bulbs are good then I guess I've got some ground problem common to all three lights. I guess past the fuse and before the wires which split off to the three lights. where would be a good place to start looking?
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  2. rickjaffe

    rickjaffe Formula Junior

    Mar 6, 2005
    362
    houston
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    richard jaffe
    actually it turns out the the light in the back works, but only in the "always on position." it doesn't go on after the door opens. the other two lights don't work at all. so I guess I have two problems; a relay problem with the door opening relay, and a light problem for the two door lights. may try to buy a light bulb to make sure it's not the bulb. though it's a filiment type bulb (kind of light a fuse) and the filiment is intact, so it may not be the bulb. will continue to play around with it.
     
  3. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    16,691
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    Hugh G. Rection
    I don't believe there are any relays in the door light circuit. It is a pretty simple layout. Check and verify the pin switch operation in the door jams. Both of mine were intermittent in operation and a spent considerable time rebuilding them to get them to work properly.
     
  4. enjoythemusic

    enjoythemusic F1 World Champ

    Apr 20, 2002
    10,675
    Worldwide
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    Steven
    Yes, the door relays are a pain in the arse! i found a substitute that works as the stock units are nearly impossible to rebuild (i tried) and NOS units are fabricated Unobtanium (TM Verell)

    http://www.ferrarichat.com/forum/showthread.php?t=28099&highlight=308+door+switch
     
  5. Dr Tommy Cosgrove

    Dr Tommy Cosgrove Two Time F1 World Champ
    Rossa Subscribed Owner

    May 4, 2001
    28,830
    Birmingham, AL
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    Tommy
    My 308 has that stupid delay thing on the light when you close the door. I HATE those things. I try to keep it "off" but every once in a while it gets switched back on and I'll forget I did it. I'll end up standing outside the car waiting for it to go off before I go in afraid I just have it in the on-all-the-time position and will have a dead battery when I want to drive it again in a week.
    What's the point of those things, to scare away a crook? Anybody have a way to fix it for good so it goes out when the door shuts like it should?
     
  6. Verell

    Verell F1 Veteran
    Owner Consultant

    May 5, 2001
    6,967
    Groton, MA
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    Verell Boaen
    Purpose of the delay off relay is to give you a bit of light to find the key to lock the car & while walking into the house. I happen to like it.

    My QV has the delay off relay also. It's gotten very flakey lately, need to fix or replace it. Haven't had time to chase it down, but it's not on the std relay panel. where is it located, one of the black boxes under the dash by the steering column?
     
  7. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    16,691
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    Hugh G. Rection
    I don't believe the GT4 ever had the "delay off" relay....that was only on the QV's and 328's forward.
     
  8. gerritv

    gerritv Formula 3

    Jun 18, 2001
    1,400
    St Catharines
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    Gerrit
    Hi Rick

    No relays involved in the door light circuit. These funky lights have 3 positions. One for always on, on for always off, the other for control by the door jamb switch. Those switches (one for each door) is where to look first. Check the grounds (ALWAYS check the grounds this is the curse of older Ferrari's). Then check to see if the switch does its job. Either door open should light all 3 interior lights and the lights at traling end of doors. While the GT4's didn't have official light delays, the bad connection and ground may result in the same effect at times :)
    To get at the switche connections, remove the two screws holding the cover panel (the one that hides the door hinges).
    Lastly be glad your lights stay in the door. Mostly mine fall out when the door shuts!
    If you need a photo of which wires go where, just let me know and I will take one.

    Gerrit
    http://dino308gt4.com
     
  9. Dr Tommy Cosgrove

    Dr Tommy Cosgrove Two Time F1 World Champ
    Rossa Subscribed Owner

    May 4, 2001
    28,830
    Birmingham, AL
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    Tommy
    I guess my problem is that my front door to my house is too far away to be illuminated by the dome light.
     
  10. Verell

    Verell F1 Veteran
    Owner Consultant

    May 5, 2001
    6,967
    Groton, MA
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    Verell Boaen
    Rathar than start a new thread on this topic, I'm resurrecting this one.

    Now that I've got my A/C working, thought I'd try to get my interior light relay working. My interior lights are always on with the switch in the rear position.

    Can anyone tell me where the interior light relay is? I'm assuming it's also the same part that provides the off-delay function & either the contacts are stuck, or the delay function has failed such that it's not timing out.

    I'm sure I could eventually find it by chasing the wires, but am hoping someone has experience to share.
     
  11. dpospres

    dpospres Formula Junior
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    Jun 29, 2005
    261
    Middle River, MD
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    Dave P
    The interior light delay is a module located behind the passenger footwell (at least on the 308 QV). It also controls the seatbelt light.
     
  12. Verell

    Verell F1 Veteran
    Owner Consultant

    May 5, 2001
    6,967
    Groton, MA
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    Verell Boaen
    OK,
    Tnx, forgot to look there.

    It's a Euro, so s/b the only thing there as doesn't have the cat sensor boxes that are usually there.

    Hopefully I'll get a chance to look for it this weekend.
     
  13. miked

    miked Formula Junior

    Feb 7, 2001
    619
    Cincinnati, Ohio
    Full Name:
    Mike Dawson
    Rick, The GT4 doesn't have any relays, time delays etc., just basic wiring. I assume you have confirmed 12v power to the circuit and good bulbs. 9 out of 10 times the problem is a poor ground at the door switch located in the plate that covers the hinges. Either the switch itself needs the contacts cleaned or the body of the switch isn't grounding to the plate. The plate may not be grounding to the car body if it has been repainted. The switch provides a path for the power to get to ground AFTER it has passed through the bulbs. Just pop a switch out of the panel to clean the contact. If you ground the wire the lights should come on. The lights themselves also have contacts that need cleaning. The selecter switch in the light just chooses which path to ground is available (through the door jamb switch, directly to ground or no ground). BTW, VW Rabbits (or is it the bug?) use an identical light made of plastic instead of glass/chrome, not concours correct but at $10, a "driver" consideration. The light just pops out of the door panel, as already mentioned, sometimes whenever you shut the door! Sunroof cars do not have the light over the rear window due to the lower headliner but the wiring is there. This could be a source for dead shorts if you have a sunroof.

    Once you get the interior lights to work, the next step is the red safety lights on the rear edge of the doors. Those guys with the neon lights under their cars will be green with envy when you open one door and the door gap on the other side lights up bright red!
     

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