Window Switch Not Lit

[ford2688]

Hi,
On my 2000 xlt drivers door the illumination went out on all the window buttons, door lock button and remote mirror switch. I think that's 11 LED bulbs all together.
It's not a fuse or dimmer switch.

The passenger side window and door lock buttons are lit and all the windows work, the remote mirrors work and door locks work from either door.
It's just that the buttons are not lit on the drivers door.

I had the panel off and I did take the switch apart.
they are LED and soldered into the board.

How do you check a LED bulb? (very low voltage?) Which of all those wires deal with illumination and how do you check them??

Find it hard to believe that all these bulbs went at the same time only on that door, and I think that the only connection between the windows, door locks and remote mirrors is the fact that all the buttons get lit at the same time.
Also noticed that the headlight switch is not lit up, but I don't know if thats been that way for a while or not.
Any ideas?
Thanks, Angelo

[shorod]

An LED is a Light Emitting Diode, so you can test them using the diode function on a digital multimeter. With the red meter lead on the anode of the diode and the black lead on the cathode, you should get around a 0.5 V drop across the LED. Depending on the test current of your meter, a good LED may dimmly light as well. Reverse the leads and you'll get an OL or "overload" indication on your meter. This would be a good LED. LEDs rarely "burn out" so, as you suspect, your problem is likely elsewhere.

The illumination comes into the master window/door lock switch on the pair of Red/Black wires at connector locations 5 and 12. The corresponding grounds are black wires in connector locations 1 and 14. The illumination signal is a pulse width modulated voltage, so I'm not sure if it's coming in at (full brightness) or if it is something more LED-friendly, like 3V. To test the LEDs, you'll probably need to do that at the LEDs rather than at the connector. However, I'd suggest you start by checking for voltage at the connector.

I don't believe there is any illumination on the remote mirror switch though.

-Rod

[ford2688]

shorod , thanks for the informative reply.
I'll check this out.
Thanks again, Angelo