Taillights and fog lights just quit working.
Brake lights are fine.
Any ideas?

 

Check or replace this fuse (refer to attached diagram).
Is the interior switch and controls illumination working when the tail light or headlight switch is turned on?
Power for the fog light relay is also protected by the tail light fuse.

 

changed that fuse and still not taillights.

 

Perform this test to help isolate the cause (refer to attached drawings):

NOTE: you do not need the key fob for this test.
Open the driver's door and rotate the headlight control to the position indicated by the blue arrow.
Check if any of these lights are On . . . . .
- Amber front marker lights (location indicated by green circle)
- Parking lights (indicated by green arrow)
- License plate illumination (red arrows)
- Driver's door mirror switch and window switch illumination ***

*** May be hard to see in daylight. Rotate the headlight control between Off and the blue arrow position while looking at the white printing on the switches.

 

Did the test and none of those lights are on.

 

Refer to the attached tail lights / fog lights flow diagram. Unfortunately, none of the lights turning on means the problem could be anywhere in the diagram, including loose connectors and broken wires (rare).
An important question: Did any repair or event occur just before the tail lights stopped working?

If you are lucky, the cause could be one defective light that blows the fuse. After you replaced the fuse, the new one could have also blown the first time you tried to turn on the lights. Was the removed fuse tested with a meter? If you are unlucky, the cause could be a failed tail light relay, which is not an individually-replaceable component on the NX. The entire power distribution module (called "junction block" by Lexus/Toyota), located behind the dashboard, must be replaced.

The next relatively-easy test requires a voltmeter. The type Harbor Freight sometimes gives away with any purchase is adequate. Do you have one?