Help! Testarossa turn signals not working. | FerrariChat

Help! Testarossa turn signals not working.

Discussion in 'Technical Q&A' started by Colin78, Sep 25, 2022.

Tags:

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

  1. Colin78

    Colin78 Rookie

    Jun 6, 2022
    13
    Full Name:
    Colin Barrett
    #1 Colin78, Sep 25, 2022
    Hi everyone. I've replaced my hazards lights button yesterday on my (recently purchased) 1991 Testarossa (the previous owner glued down the old hazards button because the spring was busted.). This means I can now turn on/off the hazards ....however now my left/right turn signals have stopped working! I know the hazards button has to be connected to complete the circuit to allow the L/R turn signals to work. They worked fine with the old button, and temporarily with the new button yesterday. Now the L/R turn signals won't work at all with either the new or old hazards button in place (despite the hazards working fine). My thinking is I must have blown something (possibly connecting up the new hazards button incorrectly). Surely if the relevant fuse was blown the hazards would also not work? Any thoughts/suggestions??
     
  2. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,147
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #2 Steve Magnusson, Sep 25, 2022
    No, the turn signals only work with the key "on" (+12V power from fuse #24). The hazards work with the key "off" (+12V power from fuse #4). Check fuse #24 first.

    It's the Flasher that is OK if either the turn signals or hazards work (not the +12V power).
     
  3. Colin78

    Colin78 Rookie

    Jun 6, 2022
    13
    Full Name:
    Colin Barrett
    #3 Colin78, Sep 25, 2022
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,147
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #4 Steve Magnusson, Sep 25, 2022
    Yes. If that #24 fuse is OK, but the turn signals don't work, also check to see if (key "on") the reverse lights work, or not = that can give a clue about where the trouble might be (upstream of fuse #24 or downstream of fuse #24).
     
  5. wmuno

    wmuno Formula Junior
    Silver Subscribed

    Dec 24, 2007
    434
    Wilmette, Illinois
    Full Name:
    Bill Muno
    #5 wmuno, Sep 25, 2022
    After checking the fuses and wiring and if you are still having a problem, I have another suggestion. I have an older Ferrari and every few years I need to spray some contact cleaner into the turn signal switch in order to get consistent performance. An additional check is the turn signal blinker unit. I'm not sure if the TR still uses one of these. In my car it's a round aluminum can located under the dash; it's not with the fuse and relay panel.
     
  6. Colin78

    Colin78 Rookie

    Jun 6, 2022
    13
    Full Name:
    Colin Barrett
    #6 Colin78, Sep 25, 2022
    Unfortunately Fuse 24 seems to be intact (reverse light working fine) so back to drawing board. The problem has to be related to me changing the hazards button and likely localised to the wiring/connections/switch under the button console (It’s too coincidental otherwise). I just hope I haven’t damaged one of the ECU circuit boards. @wmuno - thanks, I don’t think there’s a separate blinker unit in the TR. there is a white plastic connector (see photo) which the hazards button plugs into. Perhaps the connections in this white plastic unit are now damaged since yesterday but it looks fine and both turn signals & hazards were working fine yesterday….now only hazards are working. This is same for both my old & replaced hazards button (see photo attached) . The hazards button has to be connected in order for turn signals to work (presumably the button creates a circuit). Not too sure what to try next….any suggestions welcome!
    Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
     
  7. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,147
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #7 Steve Magnusson, Sep 25, 2022
    Last edited: Sep 25, 2022
    Why can it never be something simple :(

    With the hazard switch plugged in to its octagonal connector, hazard switch button in "off" position, and key "on":

    1. Measure the voltage on the V (green) wire of the octagonal connector to the single black wire that goes to the center spade (this single black wire can be plugged in, or not). You should be able to touch the voltmeter probe to the metal back end of the female terminal with the V wire = should be +12V.

    2. Measure the voltage on the M (brown) wire of the octagonal connector to the single black wire that goes to the center spade (this single black wire can be plugged in, or not). You should be able to touch the voltmeter probe to the metal back end of the female terminal with the M wire = should be +12V.

    If you pass both those tests (and the turn signals don't work) = you'll probably have to go after the turn signal switch as Bill suggested.

    If you fail test 1 and test 2 = some upstream problem in getting +12V power to the hazard switch.

    If you pass test 1 and fail test 2 = bad hazard switch.

    Alternatively, with the hazard switch unplugged, if you use a jumper wire to connect the V (green) wire to the M (brown) wire in the octagonal connector (which is what the hazard switch does in the "off" position), you can then check to see if the turn signals work, or not, with the key "on".

    PS Are you substituting a hazard switch from something else? The 124086 F part has the single triangle on the button:

    https://www.ferrariparts.co.uk/part/ferrari/124086?id=68174

    like your old one.
     
  8. Colin78

    Colin78 Rookie

    Jun 6, 2022
    13
    Full Name:
    Colin Barrett
    #8 Colin78, Sep 25, 2022
    Thanks very much for the really comprehensive & knowledgeable guidance Steve!!

    Re: the replacement button…yes it’s an Alfa Romeo part. Exactly the same except it has an extra connector (labeled 30b) although there is no corresponding female terminal on the octagonal white connector. It works fine for hazards (and temporarily worked yesterday for turn signals)

    FYI: When I initially plugged in this replacement Alfa hazards button, I connected it into the wrong terminals on the white octagonal connector (this disconcertingly caused various arbitrary lights to appear on the dash) ….however it subsequently worked fine for both hazards & turn signals once placed into the correct terminals on the white connector….then turn signals stopped working 30 mins later.

    Surely the hazards would not work correctly if there wasn’t already +12v feeding ok from both the M & V wires? (However I’ll borrow a voltage meter to check.)

    Bill (@wmuno ) mentioned to spray contact cleaner into the turn signal switch….does that mean the switch within the turn single stalk off the steering column….or the flasher relay? I’m wondering could I have possibly blown the relay (wherever that is on the TR, possibly within the hazards button?).
     
  9. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,147
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #9 Steve Magnusson, Sep 25, 2022
    Last edited: Sep 25, 2022
    No, the hazard function and turn signal function are very separate things inside the hazard light switch.

    He means the sliding turn signal switch contacts inside the steering column. Your flasher relay (for the turn signals) is OK if the hazard function works -- they both use the same flasher relay.
    These are the typical F "fixed" side of the turn signals switch contacts on the left side of this photo (the turn signal arm connects the large center pole to nothing when "off" and to one or the other smaller contacts for left or right operation):

    Image Unavailable, Please Login
     
  10. Colin78

    Colin78 Rookie

    Jun 6, 2022
    13
    Full Name:
    Colin Barrett
    #10 Colin78, Sep 25, 2022
    Great, thanks Steve. BTW: you also had a good suggestion about using a jumper wire to connect the V (green) wire to the M (brown) wire in the octagonal connector to simulate when the hazards button facilitates the turn signals operating. I’ve a silly question but is there anything specialised/particular I need for this or could I do it with any piece of arbitrary connecting metal (like a paper clip for example)?
     
  11. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,147
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #11 Steve Magnusson, Sep 25, 2022
    No, nothing special so you can be pretty crude about it ;). You can even just strip the ends of a wire a bit and stuff/hold the bare ends of the wire into the female spade terminals. It's just a quick temporary test.
     
  12. Colin78

    Colin78 Rookie

    Jun 6, 2022
    13
    Full Name:
    Colin Barrett
    #12 Colin78, Sep 26, 2022
    @Steve Magnusson - thanks for the suggestion! I connected the V (green) wire to the M (brown) wire in the octagonal connector and the turn signals work ok! That suggests I may have blown something in my new/replaced hazards button.
     
  13. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,147
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #13 Steve Magnusson, Sep 26, 2022
    Glad to hear that you've (possibly) identified the trouble. However, it's possible that the turn signal switch is behaving intermittently. If you measure the resistance from the male terminal on the new hazard switch (unplugged when "off") where the V wire mounts to the male terminal where the M wire mounts and get a high resistance = that would confirm the new hazard switch is bad for sure.
     
  14. Colin78

    Colin78 Rookie

    Jun 6, 2022
    13
    Full Name:
    Colin Barrett
    #14 Colin78, Oct 14, 2022
    @Steve Magnusson - I’m now all sorted! I used your suggestion of connecting only the V & M wire to test my old/new switches and it turned out the problem was with my 70’s Alfa Romeo Montreal switch with the extra spade connector. Ripping off the extra connector with pliers has got the button working. Thanks very much for your help!
     

Share This Page