Diodes everywhere....

[86 911 Targa]

It would appear that we have a "few" diode locations on our '86.

Does anyone have a physical location, and circuit application(s)
for these "little" guys at each location.

And, specifically, how they contribute to each circuit performance.

Here is the one next to the headlight switch,
I understand this specific application.

Thank,

Gerry

[steely]

No answer for you Gerry, apart from blocking reverse flow, but as to why in each case I don't know.

What is intriguing is the 'NR 10' line - do you know what it is supposed to be (in the schematic)?

[86 911 Targa]

Originally Posted by steely

No answer for you Gerry, apart from blocking reverse flow, but as to why in each case I don't know.

What is intriguing is the 'NR 10' line - do you know what it is supposed to be (in the schematic)?

The NR 10' line appears to be a diode by-pass.

When the diode fails (open) current is sent
to the right side "running " lights. (58R).

An issue experienced by myself, and other P-members.

[HawgRyder]

Sometimes diodes are added to a circuit to allow a single element bulb to be both dim and bright (tail/stop light).
The diode will drop about 0.6 Volts and if the tail light circuit is passed through the diode it will be slightly dimmer than the same light when the voltage bypassing the diode is applied.
This is an old trick for motorcycles.
Other than that....a diode will allow you to use 2 switches to power the same circuit and not join circuits together that would normally be separate (eg. a main bulb test circuit to test all indicator lights at the same time).
Hope this helps.
Bob

[McLovin]

As I recall, it is under the dash, on the driver's side, near the steering column. Kind of hard to describe in words, but it is right under the lower dash trim piece. Maybe around 6-8 inches out from the headlight switch. (look under the dash, see the wires coming out of the headlight switch, follow them 6-8 inches and you should see a plastic case holding the diode).

I've never seen a good explanation of what this particular diode is for. It doesn't appear necessary, since 86 is the only year to have it.

[86 911 Targa]

Originally Posted by McLovin

As I recall, it is under the dash, on the driver's side, near the steering column. Kind of hard to describe in words, but it is right under the lower dash trim piece. Maybe around 6-8 inches out from the headlight switch. (look under the dash, see the wires coming out of the headlight switch, follow them 6-8 inches and you should see a plastic case holding the diode).

I've never seen a good explanation of what this particular diode is for. It doesn't appear necessary, since 86 is the only year to have it.

Thanks for your comments,

Having replaced this diode in the past, I'm familiar with It's location.

The primary reason for my post, was to determine the location of the other diodes on the car, and determine their individual circuit application.

Which symtoms would indicate which diode has failed.

If a failed (open) diode is suspect while troubleshooting a circuit, the diode location would be nice.

As for the unique application of this diode on the '86 3.2's, Porsche added an additional contact to the light switch in '87.(#58).

The relevance of this added contact v/s the elimination of the diode?



'86 Switch is a 911.613.029.02
'87-'89 Switch is a 911.613.029.03

Gerry

[lucittm]

Steely and Eighty-Six,
I think the NR 10 refers to the wiring harness "Piece Number" or whatever that is in German. By looking at the schematic, where the wires are 'bunched' around a common sleeve, there is a NR designation. But I could be wrong. I just know it is not a diode bypass.

Mark

[86 911 Targa]

Originally Posted by lucittm

Steely and Eighty-Six,
I think the NR 10 refers to the wiring harness "Piece Number" or whatever that is in German. By looking at the schematic, where the wires are 'bunched' around a common sleeve, there is a NR designation. But I could be wrong. I just know it is not a diode bypass.

Mark

Correct!

What I meant to imply, is that the diode holder having a female connector on one end,
and a male on the other, could be removed, and the harness re-connected without the diode.

I should have been more specific.

Hope someone chimes in with the diode locations.

Gerry