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Porsche Boxster: 02 boxster 986Q. Can an oem foot light switch

This answer was rated:

02 boxster 986
Q. Can an oem foot light switch (99661398006A05) function as a
simple on/off switch for day running lights? If so, which terminals
are power, load and ground?
What do you mean by foot Light switch

Customer: replied 4 years ago.

A foot light switch is a standard oem porsche 5 blade accessory dash rocker or tip switch that controls interior lighting in the footwell. The part # XXXXX XXXXX This is as specific as one can get. I want to task it as an on/off switch for exterior running lights and need the wiring scheme.

Customer: replied 4 years ago.
Relist: Other.
After waiting 8 hours my question was answered with another question. Despite providing a part number I was asked what part I was asking about.
A part look-up was not done. This is not a complicated inquiry for an experienced Porsche tech.

edited to insert picture


hello, this should be all you need, it can be wired to control whatever you wish!

Customer: replied 4 years ago.

Thanks for the reply but I already had this diagram. I don't understand the symbols. So the running lights need three wires (power, load and a ground for both) to function. The oem switch has 5 contacts. My original question was which 3 wires go to which switch contacts? How do I wire 3 device leads to a 5 contact switch? I appreciate the help but this is taking far longer than it should.

Customer: replied 4 years ago.
Relist: Incomplete answer.
The 2 right most pins are for your led light i am sorry i understood what you needed to know, how much amperage are you going to pull through this switch? Pin 4 in the diagram is your incoming power, the lights you want on with the switch will go to pin 2. If you want the amber lamp on when the switch is on then run a ground to pin 5. The ground for the lamps will not run through the switch it needs to go to a body ground
Customer: replied 4 years ago.

There are 8 (four per side) 2 watt leds. How many amps is that? I'm guessing not many.

I think you should assume that I don't know a thing about car wiring or any other wiring for that matter because I don't.

You need to explain this to me like I was a ten year old. Please.

There 5 pins on this switch. Each pin has a number. What does "the two right most pins" mean? Are you referring to pin 3 and pin 5?

You say the lights I want on with the switch will go to pin 2.

But there are two wires from the running lights. When connected together these lights illuminate. Another circuit has been added to the fuse panel for them so this circuit is grounded there yes? If not, they would not go on when these two wires are jumpered right? But how do I put two wires on one pin ?

Yes, I want to know when the bumper lights are lit so yes I want the switch led illuminated when they are lit. I have a wire from a vehicle ground point (per the manual)available for the switch. Should it go to pin 5?

Lastly, you tell me pin 4 is for incomming power. But Incomming from where? There is a fused power line available from the lighter (15 watt) will this work?

Conclusion: Pins 1 and 3 are not used? If they are used what wires go to them? Which pins get which wire? this my original question.

yes that is not much, i just wanted to make sure you were not going to run say a set of fog lights off the switch or something.

yes i was referring to pins 3 and 5

you will want to take a test light and determine which of the 2 wires has power, that wire will go on pin 4

the other wire from the pair you connect to make the lights come on will go to pin 1 (i apologize i was trying to read the diagram from my phone earlier)

yes the ground will go to pin 5 to make the LED turn on

so to finish:

Customer: replied 4 years ago.

One more question before I get in this car and try it...what is a panel led?

the panel LED is the part of the switch that is illuminated regardless of the switch position
Customer: replied 4 years ago.

At night with the lights on all the other tip/rocker switch symbols ( PSM, rear spoiler, central locking system, rear window defroster etc. in the dash are illuminated...when I turn one on the little led in the switch also illuminates to tell me that the accessory is 'on'.

Some leds are red, some amber and some blue. But all are backlit in amber. Since I want to be able to see this switch at night then I should put a ground wire here. Right? Then when I turn these running lights on the little amber led light will be on in addition to the amber backlit symbol for it along with all the other backlit switch symbols. Is that correct?

correct yes
Customer: replied 4 years ago.

Thank you for your patience. Thought you might enjoy seeing the car your helping build. I've got so much to learn and so little time.

very nice looking car! big plans for it?
Customer: replied 4 years ago.

Modest plans, small upgrades and little improvements. It's about the fun factor for me not big hp or track times. Well thanks again. Just bounch this back to me and I'll give your
'rating'. You earned every bit of it. Continued success and stay safe.



i would recommend sway bars, it REALLY wakes the car up and makes it handle even better than it already does....if you have any questions at all feel free to look me up!
greasemonkey2386, ASE Certified Technician
Category: Car
Satisfied Customers: 274
Experience: ASE Certifications A1,A4,A5,and A7 10+ years professional hands-on experience
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Customer: replied 4 years ago.

We've got trouble in River City. When the foorwell light switch is wired according to directions this how it behaves:

  • amber on/off led is lit regardless of switch position when ignition is in accessory position.

  • front running lights turn on but the switch must be held in the on position. Pressing the switch will light them but they immediately go out when the on button is released.

  • none of the panel symbol backlights are lit when car is running and lights are on. They worked until I put the switch in this morning.

  • I added a ground to pin 3 for the panel led

  • pin 2 is not wired.

  • a jumper between the line and load wires will illuminate the running lights

I'm hoping that something jumps out at you as the problem because as you know I am clueless. What am I doing wrong?

That is strange, will they stay on as long as the switch is held? If you unplug the fwl switch do the other panel lights come back?
Customer: replied 4 years ago.

To the first question, yes, the running lights stay lit as long as the switch is held on. Release it and off they go.
The second question will have to wait until tomorrow.

I'm glad your still in this loop :) Until then.

Customer: replied 4 years ago.

The panel lights are working normally with this switch connected or not. Must have not been dark enough to see them yesterday. So, the amber led 'on' light is lit when the running lights are on or off.

And the switch does not stay closed when pressed. It almost sounds like the switch is defective...but is absolutely new. Is there a test I can do to it to confirm that it's ok? I have a digital multimeter but would need your instructions to do a test.


ok thats good that the rest of the lights are working correctly

i am having trouble finding a legible wiring diagram for the rest of the switch system in its stock function, trying to see if it is supposed to be a momentary contact type of switch which i do not believe that it is, let me do some more digging on that end of things

i believe the switch is ok since it works as long as it is held, i will need to confirm the design of the switch to tell you if it is in fact no good
Customer: replied 4 years ago.

None of the other oem switches have any unused pins.

Customer: replied 4 years ago.

I found this digging around the internet:


...These switches (Porsche oem rocker/tip switches) require relays because they close a circuit only when pressed. Once you let go of the switch, power flow through the switch ceases (except for the backlighting circuit of that particular switch). A lot of automotive switches work that way. When you press the switch, power energizes the relay to open or close. The relay is essentially the device that controls the flow of electricity in the circuit; the switch just tells the relay to open or close.


So this seems to answer my first question about this switch working as an on/off for my running lights. I also found this:


So the switch needs a relay. One or two? Where can I find it? How is it wired? Do the running lights need to be rewired? Last and most importantly, does this diagram depict a scheme that will allow me to turn the devices (running lights) on and off at will or is it designed to come on when the door is opened and slowly fade like the other interior lights?

the lights do not need to be rewired, i will have to look for the relay part number at work tomorrow so i can get you a source for it, however you may be able to call your friendly local Porsche dealer and ask for the footwell light relay and they should be able to give you a quote off of that

now if you were to wire it as it is shown in that relay it would be a simple on/off operation I BELIEVE, i will have to dig up the rest of the diagram for that system to be sure....lets start with finding the relay (should be able to be done with one) then send me a picture of the pins of the relay and i will label them and resend them to you
Customer: replied 4 years ago.


i will get in touch tomorrow, let me know if you find the relay at the dealer before i do!
Customer: replied 4 years ago.


dont reply to this until tomorrow or it will relock and reset our timer, ill talk to you then!
Customer: replied 4 years ago.

No luck finding a pn or circuit diagrams yet. However, info on the link below suggests that a rear window fogger relay might work. But this is actually for installing footwell lights. Here's the link:

I doubt I'll find a diagram of the necessary circuit because as I understand all this the circuit is custom. Where would the oem schematic be found for option MXX2? We only have half of it. More like a torn treasure map!


if the relay was used to make the switch function then it will work

i will try and dig up that mxx2 diagram
well i must now thank you, XXXXX XXXXX a resource that i had since forgot about! do you just want the lights you are installing to be controlled by the switch and the switch alone? i can draw you up a parts list and wiring diagram using all normal relays that will function the way you want it to and not cost an arm and a leg
Customer: replied 4 years ago.

Yes, only the oem switch to operate the front bumper lights.
I should only need one relay since the circuit load is only eight 1w leds?

You are aware that the lights are already installed and powered by a dedicated and fused circuit from the fuse panel.

They function fine used with a 3 pin 12v switch with an on/off led indicator. My objective was to use this oem switch with an on/off led indicator and back lit panel light for night driving. In other words, identical to all of this car's other tip switches.

By now you also know that my expertise in the area of auto electrics is almost nonexistent. Try to make your diagram and instructions as basic as possible. On thing that may be worth noting is my modest (very) skill with a solder gun. Which is to say that I don't burn myself as often as I used to!

ok, do you have a digital volt meter? i need you to test between pin 4 and 1 and then between 4 and 2, make sure you have continuity when the switch is pressed for both of those

you will need more than one relay to make the momentary contact function work correctly, unless i can find you a source on a latching relay which i am doing as we speak

ok got it!!! gunna need 3 relays, diagram and parts list soon

there is the diagram for the lights themselves to make them make the "on" led work on the switch will require another relay

also forgot to add, the green and yellow wires do get connected together



parts you will need for the above diagram

(1) SPDT relay napa part number GRO 44460

(1) SPST relay napa part number GRO 448405

(2) diodes available at radio shack

wiring of your color choice and length depending how far apart you want the relays ETC.

Customer: replied 4 years ago.

Good job! I'm just a little unclear. Make sure I'm seeing this right:


  • don't need 3 relays because you found a

latching relay (GRO44460) right?

  • but the device 'on' led on the Porsche switch will still require a 3rd relay?

  • while the diagram shows connection between green and yellow wire don't do it?

  • only two pins (1&2) on the switch are used?

  • the yellow and red wires are exisiting bumper light wires (line and load)?

  • boys at radio shack no help...they need diode type/size/value?

  • what wire guage should I use?

  • where do relays live in the car?


Power to the running lights is now switched. I'm leaving it this way.

no you still will need three relays total, i didnt have the third one on there because i was still figuring out a way to turn the LED on the switch on and off the 2 part numbers i gave you are for a 4 pin and a 5 pin relay, you will need another 4 pin as well yes the green and yellow should be connected together the switch has a power going to pin 4 and the 2 indicated pins going to the relays the yellow and red wires yes are the lines for the lights themselves, the red wire in the diagram is your hot wire while the yellow is the wire that is not powered until you connect power to it


the diode is a standard 12v diode, enough to block 15A will be fine


wire gauge should not matter much as long as it is not tiny, the same gauge you used for the lights should be fine you will have to just make a home for this setup under the dash somewhere


here is the new diagram with the relay for the led...if the pins for the switch are not discussed in the diagram they stay as they were before



greasemonkey2386, ASE Certified Technician
Category: Car
Satisfied Customers: 274
Experience: ASE Certifications A1,A4,A5,and A7 10+ years professional hands-on experience
greasemonkey2386 and 5 other Car Specialists are ready to help you