So, I think my blazer hates me. I'll get to the reverse lights in a minute. My wife, son and I went out for dinner last night and stopped at the store afterwards for a few things. All of these things happened in 1 trip. First stop, Driver's seat belt button got stuck down. I currently use a butter knife to pop it back up so I can buckle it. I'll try for the junkyard next weekend. Second stop, radio stopped working, that was fixed by turning the car off and back on, but Torque lost all of my settings. After we left from there, the passenger door wouldn't close. The latch was gummed up, I was able to pry it down with my key to close the door. I soaked it in PB blaster this afternoon and it seems to be helping. Now, to the reverse lights. We went to leave today and my battery was 100% dead. I was able to jump start it but realized that my backup camera wouldn't shut off. Sure enough, the reverse lights never turn off unless I disconnect the battery. I unhooked my back up camera, no luck. I pulled the VEH B/U fuse, no luck. I also pulled the TRL B/U Fuse and it was blown, but they didn't turn off. I checked the wiring at the NSS and it looks fine. Ideas?

BTW, 2000 blazer, 4 door, 4WD, automatic.

 

If I understand correctly, your back-up lamps are on as soon as you connect the battery? First thing I would consider is the back-up camera wiring as possibly shorted to power. After market add-ons are largely the culprit in circuit problems. Next thing I would consider is the Park/Neutral switch on the left side of the trans could be the problem. You stated you removed the VEH B/U fuse (15A) and the lamps didn't shut off? Pull the B/U LP fuse (25A) in the UBEC and see if the lamps go out.

CORRECTION: Park/Neutral only gets power with key in Run/Start. Removing B/U LP fuse (25A) probably won't make a difference (yet). If you don't find problem due to after-market wiring, disconnect the connector at the at the Park/Neutral switch and reconnect battery. This will help narrow down the problem. If lamps come on, you know problem lies after the Park/Neutral switch. If lamps do not light problem is likely upstream of Park/Neutral switch.

 

First off, your are right. I should have labeled this "reverse lights won't turn off". For now I have the bulbs out. And the backup camera system is completely disconnected. I tried the B/U LP Fuse, they are still on. Also, the wiring at the NSS looks fine.

 

I made a correction, pleases see my first post again. When you say the camera is completely disconnected...where the power and ground wires (and any other wires) begin at their tap in points is/are disconnected?

 

Took a better look at the wiring diagram, you pulled the VEH B/U (15A) and lights stayed on. Appears there is short to power between there and B/U lamps OR, the circuit is also shared by your inside rear view mirror auto day/night function. Power wires are LT GRN for the lamps and the mirror.

 

Just throwing this out there, for the longest time i had no reverse lights. Last time the trans went at around 223k miles i replaced the transmission range sensor with the new trans and now they work great. Could be an internal problem in the range sensor. I would try unplugging it and see if they go out. May or may not work but it beats replacing parts that may not be bad

 

Range sensor? Are you referring to the neutral safety switch?

 

I believe the Neutral Safety Switch is contained in the range sensor. But yes, i would unplug it and see if they go out. Just for fun.

 

I can't unplug it, the wires are glued in. I would have to cut the wires. Also, I thought that now power went to the lights when the ignition was off.

 

Usually no power would go to the lights with the ignition off, you are correct. but if the problem was internal with the range sensor, if the reverse light signal wire shorted to the power at the sensor, it would always get power. I will look at my factory manual at my house when i get home to see if there is a hot at all times wire going to it. Mine is a 95. May or may not be the same. Just making sure we are looking at the same sensor here, here is the sensor on summitracing