Even when the key is turned off the brake lights remain on. I can pull the fuse to turn them off and save the battery but what is causing them to stay on and how to fix?
I need to know what the year, make and model of your vehicle
In the mean time, check the brake pedal to see if it is not hanging up. Put your foot under the pedal and push the pedal up all the way, then check and see if the brake lights went out.
It could also be a bad brake switch.
With more information I can look into the problem further.
It is a 1994 Nissan Altima, smaller of the two engines offered, 2.?L.
There is no play in the brake pedal, it can't be pulled up from behind. I tried and the lights stayed on.
Where is the brake switch and how do I replace it?
The stop light switch is located on the brake pedal support.
Disconnect the switch electrical connectors.
Loosen switch retaining locknut and remove switch.
Reverse procedure to install.
Disconnect the wire connector on the brake switch and see if the brake lights go out, if they do replace the switch.
Also be sure the brake light switch is adjusted correctly. The plunger on the switch should be fully depressed with your foot off the pedal.
Just my luck, easily found the switch and disconnected the electrical and the lights stayed on! I pulled the switch and tested it with a audible meter and it turned on with the plunger out and off when the plunger is in. The wiring diagram is very simple, only the fuse, the switch, lights and battery. The fuse is hot so I'm thinking a short between the fuse and switch energizes the circuit going to the lights? But I don't see how that could happen.
Check all the fuses with a test light. Sometimes when a fuse blows a circuit can get feedback power form another circuit.
According to the schematic the circuit can pull power from the Automatic speed control system, Automatic shift lock system, and the Antilock brake system. The wire that feeds the brake lights seems to be pulling power from one of these systems. Thats the wire on the other side of the fuse circuit (red/green stripe) on the brake switch. If you check the wires on the brake switch plug you probably have power on both wires when only one should have the power.
Try disconnecting one system at a time and see if the lights go out.
You can get all the information needed at ALLDATAdiy.com
Let me know how you make out.
Last edited by TechHelp2 (6/2/2010 4:41 PM)
No disrespect, I appreciate your help, but are you sure the schematic you are looking at is for a 1994? Based on the manual I have it sounds like a later model.
How do I test the wires on the brake switch plug? I assume I would touch the red voltmeter leads to one of the two slots on the connector and the black lead to ground?
The schematic I am looking at is from Alldata.com and it says it is for a 1994 Altima. The systems listed are used in the schematic but only if your car was equipped with these systems.
You can test with the positive red lead, and the black lead clipped to a good ground. With the key on you should have power to only one wire.
If you have power to both sides then something in the circuit is supplying power to the red/green stripe (B) on the plug. The red/yellow stripe (A) is powered by fuse number 18.
I apologize for the confusion, I'm just relaying to you what is on my schematic.
Look into what your car is equipped with to see if anything I listed is installed on your car.
Do the directionals work? Do the hazard lights work? These are all connected. Remove the flasher and emergency flasher to see if the lights go out.
Are you sure the brake lights are staying on or maybe both directional lights are on, maybe you are mistaking the brakes for the directionals. Have someone check the lights while you step on the brake pedal and test the directional both ways, making sure they work properly.
If the directional switch fails it is possible that both directional lights could stay illuminated.
Keep me informed on your progress.
Last edited by TechHelp2 (6/2/2010 9:17 PM)
The problem is a damaged switch down on the brake pedal.