93 512TR dome light

I recently bot a 1993 512TR as I am having the same issue/concern. Reading thru the threads i could not figure out if this was a defect from the factory that requires a fix (hack) or broke along the way.

Any help for rich and I would be greatly appreciated

 

TTT

I am starting to get a complex - everytime i post i hardly get a response

 

Flash,

It is probably the door switch. There are 2 swiches in each door jamb. One for the seat belts and the other for interior lights. Try shsorting thru the passenger side door switch.

Tony

 

Would be glad to help, but the only 512TR schematic that I have is incomplete. What I have of Fig 9 shows that your symptom makes perfect sense -- the RH door switch directly runs the RH door lights and the dome light; however, the LH door switch directly runs the LH door lights and the ignition key light, but its relationship to the dome light seems to go thru a diode inside 06625. If you can get me a decent copy of the Fig 9 (Window Motors - Interior and Door Light - Buzzer and Glove-Box Compartment) 512TR schematic, and a list the component descriptions (i.e., what is 06625?), I'd be glad to cast an eyeball over it for you -- but right now, I'd say that either the diode in 06625 has failed or you have a bad connection at 06625.

Do you guys have the seatbelt buzzer unplugged? It might be 06625?

 

I am starting to get a complex - everytime I hassle with responding to someone's question, I hardly get a response (and it should be double, or triple, pay for having to use the 512TR schematics -- they took a huge step backward in user-friendliness IMO)

I was able to confirm, thru some 512TR information that Melvok graciously sent to me, that item 06625 is the "Inserted key alarm connected with brake warning light working control" -- item 13 here:

Ferrari 512TR Parts : Table 126 - VALVES AND RELAYS

If yours is not plugged in = the dome light will not come "on" when the LH door (LHD) is opened.

If it is plugged in, and you still have dome light trouble = give a shout back, and I'll give instructions how to test it to see if it needs to be replaced (or if it is a wiring/connector problem elsewhere).

As the name implies, this gizmo should also turn the brake warning light "on" during starter motor cranking (to show the Driver that the brake warning light bulb is OK) -- so a further clue would be:

1. If your brake warning light does not come "on" during starter motor cranking, and the dome light doesn't work when the LH door is opened = most likely 06625 is unplugged,

2. If your brake warning light does come "on" during starter motor cranking, but the dome light doesn't work when the LH door is opened = most likely the diode inside 06625 has failed.

 

Steve thank you for your response

I really do appreciate the feedback and I need to get to test your theories

I will probably do this weekend - spent most of the day Sunday replacing a crank position sensor on my MB - one bolt took hours to remove

Thanks and I will respond back by monday

 

I have an even more pressing issue - there is a strong smell of gas especially when I fill gas tank up - no leak but a strong smell right by the filler cap - cap seals fine since i hear vacuum when i unscrew it so it must be something on right side of engine

anyone have any thoughts - or can direct me to a recent post

The post i found was for a TR not a 512 and I think the components are different

Thanks

 

A little late but i did test your theory

The engine light and buzzer do work but no dome light - what next

Also my dashboard lights do not work - I did read somewhere that the parking lights could have cause this if there is a ground near struts - i checked by no issue that i see

any ideas ?

Thanks and always appreciated

Dominick

 

What does "engine light" mean? If you mean that test 2 described in post #6 applies (but still no dome light with LH door opening, but LH door lights work), I'd find that item 13 mentioned previously, unplug it from the harness connector, and then connect a ~5A diode (from Radio Shack) into the harness connector in the same way as shown on your 512TR schematic (and/or measure some voltages at that harness connector).

Has your dome light been "upgraded" with higher wattage bulbs? (Same question to you Capt'n).

Have you checked/rotated the dimmer knob? And all of the related fuses are OK? Is it: 1) it's only the dashboard instrument lights that don't work, or 2) the dashboard instrument lights and the exterior parking lights are both not working?

 

I think the fuse blew - need to understand why - i will look further and report back

Thanks

 

Something like this NTE577 diode:

NTE577 1000V 5 Amp General Purpose Silicon Diode : Diodes | RadioShack.com

would be fine.

When you have item #13 unplugged, connect the cathode of the diode (the end with the white stripe) to the terminal in the harness connector with the two ZN (violet-black) wires. And connect the other end (anode) to the terminal in the harness connector with the two Z (violet) wires.

If that "fixes" the dome light operation with the LH door = splice the diode into one of those same wires (cathode lead into one ZN wire and anode lead into one Z wire) just outside the harness connector where convenient so that you can plug item #13 back in and preserve its other functions (or buy a new item #13).

If it doesn't = break out the voltmeter...

 

Anyone know what the 2 switches are called that are in the door jams that control dome/courtesy/red door lights?
Or what page or illustration of the parts manual they are located on/in?
The Ferrari part #?
If there is a substitute?

Me

 

Table 110, item #9 at Ferrari Testarossa (1990) Parts : Table 110 - DOOR PN 61503300 superceded to 141894, $46.42 from Ricambi. This switch has a single terminal and should be what you need.

I am not familiar with the internals of that switch--on other cars I have worked that switch shorts to ground when opened--if the same there are countless alternatives--none (that I am aware of) will look the same as the F-switch though, and it has a very short "throw".

Being a very simple switch, are you sure you need a new one and not just clean/lube/repair the switch you have?

 

Thanks for the heads up Tim....I never saw it on that drawing earlier.

Yeah I can't fix, the material of the plunger is broken.

I'm not a purist so if anyone knows of a screw in substitute at a reasonable price.....share.

Unpure ME

 

Thi seems to be a recurring problem with the 512TR, and in retrospect I would bet the diode in my buzzer was bad. My fix was to run a wire from the door switch directly to the wire exiting the buzzer and going to the dome light. The dome light has worked perfectly since, but if the driver's side door is open, the buzzer also sounds. I assume this cound be fixed with a diode somewhere in the line?
Anyway, it sure beats $125+ for a new buzzer relay.

 

My dome light is also not working when I open the doors. I removed the so called Courtesy Light Switch (14189) and there is a mess of cables:

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Seems like this is from an aftermarket alarm system. What seems to be original are 3 wires:

• brown/white (dead, no ground, no voltage)
• gray + brown/blue (+12V)

When I shortcut brown/white to the black cable (which looks aftermarket), the dome light starts shining.

So in the end I have 3 cables and only two pins at the switch. What would be the correct wiring?

 

Black is always ground at F-world but in this case as it looks aftermarket I would test it first if this has power from somewhere

 

Thanks, it's fixed.
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The two violet cables (together) and the black ground go to the Courtesy Light Switch (14189). The rest is aftermarket and removed.

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Now the dome light goes on and off when I open and close the doors.