Turn signal always illuminated when headlights on

Chris,

If you don't find anything wrong (no bridging between the pins 8 & 9) in the loom side connector for the rear RH lamp, it is quite likely that you have a fault in the front RH fog/indicator lamp. I suggest you unplug its 3 connectors (see pic above) and see whether the rear Righ Indicator is no longer lit-up when you switch the P-switch, or the column switch, "on".

Let us know the result and, if it proves that there is a problem in the front lamp, we will assist you as to how to rectify it.

You did some work on the front fog/indicator lamps as shown in yout thread I quoted above. Did the present problem start since then? If you changed the amber bulbs, did you use dual fillament bulbs in both, F and B, locations?

 

At this point, I'm getting a strange feeling of de ja vu.

It seems strange that the Owner's Manual would be wrong. As for the wiring diagrams, they are too blurry to see any detail. If the fog and daytime flasher are the same lamp (like the F355), we need to see where the wires join up. On the F355 there are splices outside the lamp. There are no external splices visible on the illegible USA diagram.

Pin 2 of the 3 pin plug went to daytime flasher on the Euro car and now it goes to light B (front marker and side marker), so the car or relay panel wiring must be completely different from the Euro car.


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Unfortunately, I don't have enough data to complete the full USA diagram.

Isn't it impossible to put a two pin lamp in a 3 pin slot... or can they be forced? I thought about this earlier, but assumed it couldn't be done.

 

I think this is as far as we can go with the US Fog Lamps as we do not have a clear enough wiring diagram for lighting. As for the Daytime Flasher on US cars, it either does not exist or the Fog Bulb is also used as the Daytime Flasher. Can any member with a US spec 348 clarify this point?

If you want to be fully in line with the actual arrangement of the US lamp wiring, you should show the yellow/red wire extending into the lamp, to approx half height of the lamp, from where its continuation to the light B is yellow (as you have shown it). Then show both wires for the rectangular Side Marker as branched off inside the lamp, from the black wire and from the point where the yellow/red changes to yellow. The Rectangular marker wires then come out of the lamp body and go to the inline connector and further to the Side Marker. This arrangement (simplified) can be recognised on the blurry US diagram posted by a member earlier. Here's the RH lamp detail from it:

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As for the dual fillament bulb sockets, it should not be possible to insert single fillament bulbs but one could force them, I guess. I asked Chris to check this (just in case) because he mentioned in one of his post that it looked like somebody previously did some work on the lights wiring. Let's see what Chris comes back with.

 

Unfortunately, I ran out of room in the lamp assembly to show the loop to the rectangular marker.

 

Perhaps like this? (need to change the "G" at the wire from Pin 2 of 3-way to "GR")
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You might be able to isolate the problem to a particular corner of the car, but it would involve disconnecting plugs on the back of the footwell relay panel.

If you disconnect plugs F and H and then do a continuity/resistance check between the yellow and blue wires at the rear RH light connector, that would prove the short was in the wiring to the right rear corner (if the yellow and blue wires showed continuity).

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There should only be one bolt holding the relay panel in place (on one side). The plugs can sometimes be very difficult to remove. Be sure to remove power before doing this.

Of course, this assumes the wiring diagrams are mostly correct.

I'm not sure how you would further isolate the problem if the short was in this line, other than monitoring your meter and shaking the wiring to see if the resistance value changes. In the aviation industry, we have some equipment which can monitor anomalies in wiring (but it costs thousands of dollars).

 

My last suggestion was that you disconnect the Front Right Fog/Indicator Lamp. Did you see it, post #101?

 

Chris, how did you come up with LF assembly from these messages?

 

Never mind the word "indicator", it is your question "Do you want me to unplug the LF assembly" (what do you mean by "LF assembly"?). I suggested that you unplug the Front RIGHT Fog/Indicator Lamp (the RHS front fog/indicator assembly).

You should have no problem doing it because you already removed it once (see you post https://www.ferrarichat.com/forum/threads/front-turn-signal-assembly.681444/#post-149269442).

 

Those "yellow splice" connectors can't be stock. Compare that existing wiring to the schematic to see if it matches, or not.

 

Before you cut it....

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Do you have all 4 wires going into one splice (i.e. 1 blue and yellow on the incoming side and 2 blue coming out)?

 

You need to separate the 4 wires into two pairs.

I don't know why you have two blue wires going into that upper lamp (in the photo)

(EDIT: are there two blue?)

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Do you have a dual element lamp in that upper bulb? (in the photo)

If so, you need two wires going in there (not including that earth). i.e. a blue and yellow wire.