Hi Steve,
This is a reply from our tech guy who handles electrical issues.
LED’s enjoy a stellar reputation, However, it would be wrong to say they never have issues. It’s rare, but it happens.
Our suggestion would be to take the bulbs and a pair of jumper leads, then go to your battery.
Use the battery to apply power to the LED’s.
If they light, the bulbs are fine.
If the bulbs are fine, the most common problem is a weak wire connection or ground issues with the sockets.
In case you want to know…
When electricity faces an obstacle, it tries to get through it. Electricity’s capacity to overcome obstacles is measured in voltage. (Your car battery has enough amperage to kill you. However, you can put your hands on the two terminals and nothing happens to you. The reason is voltage. 12 volts cannot overcome the resistance in your body. If you try the same test with a 120 volt wall outlet at home, you will get a different outcome.) The voltage needed to overcome a specific level of resistance is called break-down voltage. LED’s have very little voltage going through them. So, their ability to break through resistance is limited.
That’s why clean wire connections and clean sockets are so important.
Let me know if you have any other questions.
Shawn