95 PF Brake light issue

[aikiwaza]

I have a 95 Pathfinder. The brake lights have quit working. The backing, turn signal, and the lights that turn on when headlights are on all work. There is no current to the brake lights when pedal is depressed. Is there a fuse that I overlooked. The only other thing I could think of is that the factory trailer plug is kinda messed up... it takes a bit to get the plug to connect right. The trailer has the same issue when hooked up... all lights except brake.

[88pathoffroad]

Check your brake light switch under the dash on the pedal.

[aikiwaza]

How do I test it?... I am assuming that you are talking about the button just in front of the brake pedal... it depresses when the brake is applied. There are two there side by side... the one closest to the passenger side is the release for the tranny shifter (automatic) and the left most I am assuming is for the brake... The tranny release works and the brake switch doesn't stick and is okay as far as a visual inspection goes. Do I just have to replace it to find out if that is the problem, if so what is the easiest way to do this? Is there a test for the wire harness that leads to it so that I can check and see if there is power even running that far?

[88pathoffroad]

If you have a volt/ohmmeter (they're cheap nowadays) you can simply set it to ohms and test the switch's plug leads. Press the switch while watching the voltmeter and it should go from open to close or vice versa.

[aikiwaza]

I have confirmed that the switch is good without question... a new switch still doesn't fix the problem either. I checked the current coming from the harness that connects to the switch for the brake lights and found that there is no power going to it with the car on or off (though for a brake light it should have constent power even when the ignition is off right?) Is there anything else I can check... any other harnesses or relays, fuses etc.? I am out of ideas, the repair manuals are of no help, and the only thing the garage says is check the switch (or I can have them take it for three days and try to troubleshoot it them selves... unfortunately I can't let the car go for that long.)

[denisb]

First off make sure you don't have two bad bulbs in the back of your truck. I've seen chassing my tail over a stupid oversite like "oh it can't be that both bulbs are bad" beleive me it can happen.

You said you checked and there was no power going to the bulb, did you check both sides of the bulb to a known good ground on the vehicle (clean metal screw screwed through the body is the best location)? You can probably find one close to the taillight.

Nissan switches the ground side of the circuit on their vehicles. This makes for a little trickier testing. With a test light and with the brakes not applied, you should have light on one side and none on the other. With your brakes applied (switch pressed if it's easier), your test light should be off, if it's on, you have a bad ground. If you don't get light on either, you have a broken wire from your switch to your taillight.

Hope this helps,

Denis

[aikiwaza]

Finally got it fixed... the problem was two fold...
1. The trailer wiring (being old) had lost ground and a slice in one wire caused a short... while it wasn't the direct cause for the brake light failure it didn't help it (blew the fuse when I did find and fix the problem)

2. The wiring harness to the switch had some how gotten kicked on, nudged... something... and caused a wire to come disconnected from the harness slot without actually pulling the wire out of the harness... don't know why I didn't find it when I was checking the switch, but when I fixed it I got lights again.

Thanks for everybody's help on this