Nice! Was going to cut one of mine open regardless to see whats what inside. This saved me the trouble so I could get the new led's ahead of time. Cut it open, replaced the LED's, tested, now its sitting with some silicone on the back curing before I reinstall it. Thanks OP!

 

I soldered two led bulbs to my side marker light after opening it up, but only one light worked. I replaced the one that waa not working and it still wouldn't come on. What else could be wrong?

 

Perhaps it was soldered in with wrong polarity. Or, it was defective. The circuit shows only a diode and resister in the twin diode circuit. If either of those are blown, nothing works.

 

Thank you for your reply. What do you mean by "Perhaps it was soldered in with wrong polarity"?

 

 

These 4 pin square LED's are a bit different. One corner is notched and there is a silkscreened line in the circuit board that also shows the square with the notched corner. The pics on the last page show it, pretty obvious. As long as its installed matching the markings on the board it "should" work. I'd definitely recommend testing before resealing the ling with silicone. It is possible that either the resistor or diode have gone bad. Either one of those out would cause one led to not light.

Either way I'd just double check the solder joints on everything. I did run into the very same thing. I re soldered everything including reheating the solder joints on the diode and resistor and that got both of mine working.

 

Yes I see the notch! Thanks so much!

 

If you solder in an LED the polarity must be correct. D.C.- to the correct post and D.C.+ to the other. If it doesn't light up switch the polarity. You probably soldered it backwards. It is a diode and D.C. Current will only flow one way.

 

Well I'm still having a huge problem. I took out the side marker because none of the lights are working. The side marker has two lights and both were not working. So I unsoldered the four point LED light and then resolder a new one. And I went to the vehicle and found that the side marker lights now work. Remember I only did one of the LEDs. So instead of replacing the second LED I went ahead and install the side marker in my truck and took it down to the dealership to be inspected. In Virginia you have to have your side marker lights working or it doesn't pass inspection period when I got to the dealership the side marker was working but during the inspection it decided not to work anymore. I took the side marker apart when I got home and found that I did have the LED put in correctly. But remember both LEDs are not working when I did the initial repair period after I replace the right LED I went outside to try it and found both lights for now working period so now I've got a side marker that does not have either light working when they were both working yesterday. So I just want to know if anyone can give me advice before I re-attempt this repair. Do you think I should just install two new LEDs?

 

Check solder joints by applying more solder to all the back side pins and the diode and resister and the wires soldered to board. Also the connector maybe bad and a little electrical grease in the boot might help it.