Backup lights only come on briefly

Okay guys, save me again.
I ordered a bunch of LED lights for my husbands truck for Christmas. Installed the hi/lo’, and the map lights, no problem. Realized his dome light doesn’t work, will track this down next. Working on the backup lights. Just realized his backup lights don’t work, don’t know how long they’ve been gone, but they don’t work. Checked all fuses, all are okay. In checking things out I realize that on occasion the lights come on for a second or two. Reading past posts I saw suggestions that it could be the backup light switch and saw to test it with a bridge made from a paper clip. Tried that, even though the switch didn’t look exactly the same (4 prongs instead of the 2 shown) got good light to one side. Started trying to research backup light switches but can’t find anything that gives me a clear understanding of the difference (if there is any) in the switch for an automatic vs. manual. I’m not afraid to dig in to something I’ve never done before, but would appreciate some guidance. Where is, what is, and what do I need to do kind of advice. Be kind please, I’m a soon to be 60 yr old woman who, in a life that seems a long, long, time ago, used to be a diesel mechanic (back when there were no women in the field) so I love doing everything, I just haven’t gotten comfortable with the electrical stuff.

 

Hope you bought good quality led lights. So many people have problems with cheap/low quality leds. Some even have problems with good quality lens. Truck electrical system is not designed to run leds. BCM (body control module) go out with leds problems. Just what I have seen on here.

 

I would put everything back to factory, make sure everything works, then start with one led at a time and make sure everything works after each one. Seems tedious but that’ll probably be the only way to figure this out since this is an electrical problem.

 

Not sure it's necessary to return everything back to stock for troubleshooting the backup lights circuit, but definitely would help using a known good bulb. Attached is the EWD for what you are diving into.

 

Gosh, Iv'e read so many horror stories on here about switching bulbs to LED, especially if the neg battery terminal isn't disconnected.
Back in the day things were so simple. Now, with sensitive electronics, you really have to be careful.

 

Some LED bulbs, as opposed to incandescent bulbs are polarity sensitive. If they do not work one way, you may have them inserted into their holder incorrectly and need to rotate them and re-insert.
People love these LED bulbs, but unlike incandescent, they don't necessarily have the same fail safe mode.
An incandescent fails when the filament breaks and presents no problem to a wiring circuit. It is considered to have failed safely.
An LED bulb when it fails... YMMV

 

OP stated that they did work in the past, so it wouldn't be a polarity issue.

There are so many cheaper brands of LEDs out there you'll want to spend the money to go with a known brand.

 

I went with the LED’s from Lasfit, which I had been assured was a good brand from guys on 2 of the Tacoma Facebook pages. Was I misled?

 

As someone previously said, always disconnect the battery negative terminal before replacing bulbs.
Are you sure the dome light switch isn’t in the off position?
I would disconnect the negative battery terminal, replace the backup light leds with regular bulbs and see if they work again. If they do then the leds were bad (or possibly backwards?). At the same time replace the dome led with a regular bulb (bat negative disconnected!) if the problem wasn’t the dome light switch in the Off position.
Then go from there to find better led bulbs if all is working.

 

Never heard of them.

 

Just thought I’d let everyone know. Turned out to be a simple polarity issue (always read the teeny tiny print). The dome light is actually the fixture itself
and I will be replacing the fixture. All LED’s work great, incredible difference and the Lasfit LED’s are great. The tailgate light bar I installed is from Opt-7 and it’s absolutely astounding how much light it gives out (brake/turn/backup) I’m super pleased. Now I get to track down some training on how to fully use the multimeter I scored while working on this project. There are definite advantages to being the mechanical one in the family, I get some great toys while working on other peoples stuff.