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I recently replaced an LED license plate frame with third brake light because the original stopped working. It was 16 years old. I wired the new frame according to instructions (designed for a 12v system) and everything seemed to be fine.

However, after having the trike on the road only 3 times since the replacement, the fuse has blown 3 times: it didn't blow the first day, but it did once the second day out, and so far twice today (I'm at work; will still have to take my chances going home).

When it blows it takes out all of my running lights and my turn signals, but my brake lights still work (I had originally thought it wiped out my brake lights, too).

The fuse does not blow right away. It takes a while, usually a mile or more.

I am a bit perplexed. My first impression is an exposed/shorted wire (original wires that I plugged into). Beyond that, I'm not sure. If the last setup was LED and this one is also, and I used the same terminals to connect the wires, and followed written instructions, then I don't understand how this could be happening unless there is something defective in the manufacturing?

The license plate illuminators use tiny 20 or 18 ga. wires, and the third brake light uses a step or two larger, if that amounts to anything? Same as the old license plate lights that stopped working completely.

I'm thinking I might disconnect the third brake light wires and see what happens, then go from there. I still have primary brake lights in the fins.

I think you are on the right track with the exposed wire or defective unit theory. I have spliced many wires over the years with slighly different guages with no issues. Would not be suprised if it is the plate frame being as most are manufactured overseas with questionable quality control.

I have also had car issues where an exposed wire would blow the fuse after a short time due to vibration.

License frame wires are ruled out. Disconnected all of them and the fuse popped anyway. Time to play seek and go hide with all the light wires...

I'm fairly certain I have located the culprit: a break in the insulation of the right front turn signal wire. It had to have been vibrating and making contact with the highway bar (crash bar, whatever you choose to call it).

So far tests in the garage are turning out fine. I will reconnect the LED license plate frame later tonight and go from there.

The ride to work was uneventful. I will declare this issue resolved.

Root cause: rip in the insulation of a turn signal, causing a short.

Glad it was an easy fix.