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Club 4X4 Panamá
Apr 4, 2003
Hello all ... forum should have an electronic section ..? ( maybe it is .. I just don't know where ? )

Here is my question / situation ..

So I'm a LED freak and replacing every single bulb on my 76 face the turning lights .. since my model for some reason don't have ( or I've been unable to locate it ) flasher to be replaced with an electronic LED ready I got to add load resistors ( 6 ohms 50 Watts )..

Here is the interesting thing .. on the rear I use these ( working flawless ) ..

and when attempted to do the same in the front, they didn't work .. more interesting stuff it's these ones do work ..

Anyone smart enough to offer me a clue why ..?

thanks !

Did you measure the voltage/polarity at the bulb socket?

Your LED 'tower' states polarity not sensitive... So they would work whether the case was gnd (and nubbin +ve) or vv...

Did you measure the voltage/polarity at the bulb socket?

yes .. in this case you have + at bottom and - ( ground ) on the side ( walls ) so no place to change polarity ..

what caught my eye was, measure with my Fluke multimeter, with hazards on, I got 0 - 0 - 12V / 0 - 0 - 12V ( didn't measure with turning light working )

Your LED 'tower' states polarity not sensitive... So they would work whether the case was gnd (and nubbin +ve) or vv...

After contact with philips they said, those bulbs do not work for front turning lights .. and I was whaaaat .. how in hell the bulb know it's place on the front or in the back .?
Did you try them without the extra resistor? Yes they would flash too fast but it's a test you can try. Also I don't know about your truck if it is 24V and then has 12V available for things like lights? Or is it all 12V?

Maybe the Phillips are more sensitive to voltage, or it may have something to do with a switched ground like these trucks have I believe.

Just throwing things out there. I don't see anything wrong with your setup. Your resistors are in parallel correct?
Maybe the 76 has some silly 'modern' tech for turn lights...

LEDs should respond pretty well immediately to voltage applied. I'd be checking the bulb socket for GOOD contact - sometimes the nubbins do not make good/reliable contact in the bulb holders.

Not sure what you meant above by 0 - 0 - 12V ?

Do you have +12V all the time on the bulb socket and GND is then switched by the flasher or is it +12V switched and GND always present? Multimeter to determine.

I'd imagine Philips response is more that you shouldn't be running Red LEDs in the front signals...

1. I did test the philips without the resistor for sure .. no change on the outcome.

2. I test the LED philips outside with a 12V battery and they indeed work as they should.

3. Dimensions between 2 LED bulbs the ones that works and the philips are the same, ( detailed measurements ) which lead me to believe they should work

4. My 76 it's a 12V Cruiser ..

5. 0V - 0V - 12V pause and then again the multimeter reads 0V pause ( second didn't measure honestly ) 0V pause and then 12V

6. So far seems to Mr. T it's no longer using turning flasher relay and has integrated that function in the cluster or in the ECU ..

How are your US spec 200 series controlling the turning lights .?
I didn't realize we were talking about a modern vehicle. Call your friends at Phillips and ask if their bulbs are CAN bus compatible. According to Google your vehicle uses CAN buss which means your light bulbs are on a computer network.

I can't explain why rears work and fronts don't - but who knows how Toyota set up the network. One more lead to follow.

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