Installing LED stoplights?

[Jwilli]

Check the wire that connects the left light to the right light. I think it may have become disconnected. If the wire is intact you may have a ground problem.

[31 Model A]

After decoding the schematics, the trouble should lie somewhere from the left tail light going across to the right....Right???? I've gone out and laid on the cold concrete floor and checked the wiring for any breaks or bare spots that could short, I see none. I'll see if I can find a least a test light tomorrow.

[31 Model A]

Originally Posted by Jwilli

Check the wire that connects the left light to the right light. I think it may have become disconnected. If the wire is intact you may have a ground problem.

I posted too soon.....as you can read. It takes me awhile to figure things out....too much VD during my Army days has ate away most of my brain...............

[Bob Johnson]

There is something strange here. I looked closely at the two lenses and they appear to be wired differently. Below is a picture showing the same circuit board for each lens. If I am reading the color bands correctly the top lens is using 18 ohm resistors and the bottom is using 82 ohm resistors. Also the top lens has 2 more resistors than the bottom one. I know that many LED devices for cars use a resistor in series with the LEDs to lower the voltage to 3-4 volts. Is it possible that the top lens is for 6V and the bottom one is for 12V?

If the 12V has 2 sets of LEDs in series with the resistor when I do the math I get that the LEDs are drawing 0.09375 amps at 4.375 volts or 46 ohms. If there are 3 sets in series I get 0.18 amps at 2.76 volts or 15.3 ohms which is closer to what I believe an LED will use.


Bob

[huddy]

The printed circuits are completely different. On the upper assembly, notice the triangular pad by the resistor labeled "Extra" and the narrow reverse C shaped pad on the right side. Don't know what to make of that, except that the assemblies are different, but possibly could or could not be functionally the same.

[31 Model A]

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Originally Posted by Bob Johnson

There is something strange here. I looked closely at the two lenses and they appear to be wired differently. Below is a picture showing the same circuit board for each lens. If I am reading the color bands correctly the top lens is using 18 ohm resistors and the bottom is using 82 ohm resistors. Also the top lens has 2 more resistors than the bottom one. I know that many LED devices for cars use a resistor in series with the LEDs to lower the voltage to 3-4 volts. Is it possible that the top lens is for 6V and the bottom one is for 12V?

If I do the math I get that the LEDs are drawing 0.09375 amps at 4.375 volts or 46 ohms.


Bob

Hi Bob....went out and dug the packaging for each light out of the trash and both say clearly Red Lens Kit, 6-volt. One driver's side and the other passenger side. What I will do tomorrow is remove the driver's side LED and put the bulbs back in and do the same for the other side and see if the driver's side is somehow shorting the other side out.

[31 Model A]

Originally Posted by huddy

The printed circuits look different. Notice the triangular pad by the resistor labeled "Extra" and the narrow reverse C shaped pad on the right side. Don't know what to make of that.

There is a circuit for the license plate lens, could that be it?

[Y-Blockhead]

Can you switch the LED that is working to the side that isn't. My thinking is if you did get one 6v and one 12v LED by mistake the 6v is positive ground and 12v is negative ground.
You have to have the polarity correct on LED's to work.

[31 Model A]

I don't see how this could be a factor but......my passenger side light is also a driver's side light with the license plate lens. I covered it up and put in a passenger side LED. Connects the same as the driver's side except no wire or lens is provided on the passenger side LED.

[Y-Blockhead]

You do have a 6v and a 12v. It's printed right there on the left...

[31 Model A]

Originally Posted by Y-Blockhead

Can you switch the LED that is working to the side that isn't. My thinking is if you did get one 6v and one 12v LED by mistake the 6v is positive ground and 12v is negative ground.
You have to have the polarity correct on LED's to work.

I'll return everything as it was tomorrow and see what happens. If all is well as it was, then I try what you said and see if what you suggest is the problem.

[Bob Johnson]

One of the circuit boards is clearly labeled 12V. The other one is unlabeled. Is it possible that you got a 12V lens in a 6V package?

Bob

[Y-Blockhead]

From Snyder's "The 12 volt is negative ground and the 6 volt is positive ground."

[31 Model A]

Originally Posted by Y-Blockhead

You do have a 6v and a 12v. It's printed right there on the left...

Did I mention I'm deaf and dumb in both eyes????? The packaging plainly states 6 volt.

[Y-Blockhead]

Originally Posted by Bob Johnson

One of the circuit boards is clearly labeled 12V. The other one is unlabeled. Is it possible that you got a 12V lens in a 6V package?

Bob

Bob it is labeled, one says 6v and one says 12v. Look close on the far left.

[31 Model A]

Originally Posted by Bob Johnson

One of the circuit boards is clearly labeled 12V. The other one is unlabeled. Is it possible that you got a 12V lens in a 6V package?

Bob

That seems to be the story. I'll package it up and send it on back tomorrow.

That's for all the time and help guys!!! Simple problem solves BUT!!!!!

earlier when I took the passenger LED back out and put the bulbs back in, I still didn't get anything. Would the 6 volt LED cancel out the 6 volt bulbs?

[Bob Johnson]

Yep I see the 6V now is is not in the same place and not as clear.

[Bob Johnson]

If you look at the diodes near the red wire at the top you will see that the 6V is reversed compared to the 12V. That confirms that the polarities are different, 6V pos ground, 12V neg ground.

Bob

[Y-Blockhead]

Originally Posted by 31 Model A

Earlier when I took the passenger LED back out and put the bulbs back in, I still didn't get anything. Would the 6 volt LED cancel out the 6 volt bulbs?

Don't have an answer on that one. I do know it takes a lot more power for a regular bulb than a LED...

[31 Model A]

It would have bugged the hell out of me, so I went out and removed the 12 volt passenger side LED and put it back into it's packaging.

Goodnight and thanks again for seeing what I couldn't..............