I previously purchased the LED bulbs for my map lights P/N BA9s-x4-x-xVAC-CAR (https://www.superbrightleds.com/more...c-car-bulbs/6/) , and they worked fine, just litte too dim. I then purchased the replacement P/N BA9s-xHP5-CAR (https://www.superbrightleds.com/more...ofit-car/2077/), installed in the car and they did not work. Thinking I got the bad bulbs, I tested the P/N BA9s-xHP5-CAR with external power supply, and they were good. Somehow, it doesn't work when installing them in the car, while the P/N BA9s-x4-x-xVAC-CAR works fine.
I'm baffled, I don't know why and can't explain????
May be the good engineer Retro could explain.

 

I know you wanted retro but would you to confirm that the polarity is correct and did you measure the voltage coming out of the light socket.
Remember, LEDs will only light with the correct polarity whereas a regular bulb does not care about the polarity.

 

Led bulbs have a polarity if they did not work in the car just turn them around and plug back in . they will work

 

Yes. That is the first thing that I thought. Yes, the polarity is correct, I've tested it. What I am thinking now is may be there is the current limiter in the car that will prevent the bulb from working? Sound not logical, right ?.
I was an electronic technician for 10 years and an electronic Manufacturing Engineer for twenty one years and I can't not figure out the simple problem. That's the shame ! .
May be there is a demon in the car. LOL.
Retro, what do you think?

 

These BA9 (Bayonet) bulbs are polarized and thus you need to search for "Reverse Polarity BA9." I just bought some last month, specifically to change my flickering ones out. They are on Ebay under that search title. The polarity in our dome lights is reversed. It's been discussed on the LED Upgrade thread for a few years now.

 

Yes can confirm the polarity in our map lights are the opposite of what you might think. Upgraded both my maplights to super bright 6 LED boards. Had a kit which had a BA9 connector wired to the LED boards. I had to flip the wiring from the "normal" connection to the reverse in order to get the LED boards to work once the BA9 connector was plugged in. But man they are super bright now and the work to flip them was well worth it.

 

Ok, so you said the bulb is negative ground but the wiring on the holder is reversed? But why did it work with the other bulb ? They both have the same polarities, they both are negative ground. It's late now but I will confirm the polarity of the holder tomorrow.

 

"But why did it work with the other bulb?" Are you referring to the incandescent bulb? If so, they don't care about polarity.

 

Yes BGW is right - obviously both my BA9 non LEDs were working before I took em out. And my 6 LED boards only worked when I physically reversed polarity by reversing the wiring connector from the adapter base to the LED board.

 

No, BWG. If that's the case, I could understand.

I bough a pair of LEDs, they worked fine, just dim




I re-ordered another pairs, they didn't work.




They both have same polarities, both negative ground. Weird, huh ? There must be an answer. I'll find out.

 

Is it possible they are not making a good contact with the terminal socket?
When I purchased my SC, the lights did not work and I had to tighten the socket.

 

Some LED bulbs are made to handle reverse polarity (basically making them bipolar) and others (most) do not (making them mono-polar). I'm guessing that your first set were designed to be bipolar.

The map light sockets in the car are wired in reverse. What is typically ground is power and visa versa. Now why Toyota did that is anybody's guess.

 

Bravo Harold !!!
That what it is. The first set I guess they were bi-polar.
The holder has reversed polarities. +12V goes to side of the bulb and Ground goes to end of the bulb. That was the reason for the light bulbs not working.
So I took out the light assembly, thinking it's easy, just swap the wires, huh. Not that simple. I swapped the wires and ended up only one light working. and/or blew out the fuse. The light assembly involves other thing. Without a schematic, I was just guessing.
So I re-wired the way it was and now back to square one. Either I have to search for the light bulbs with reversed polarities or I have to live this not-so-bright overhead lights.

 

This is my set up. Super bright and my wfe loves it.

 

Thanks for the pictures. Looks nice.

I've learned there is something called non-polar LEDs.

I've re-ordered the non-polar LEDs. They should be in couple days, then I'll be ok to go on to next project.