running light fuses burn

Ok guys on my fjr 1300 2003 which i think we are not to many left.I have a problem that cant figure it out .I need some help from the Gurus.This is what happening. run the bike for few days and the running light fuse gets burn. Ok replace it with a new one run again for a few week then back to the same.Need some advice .

Intermittent shorts are tough....there probably aren't any easy answers. But some questions to consider:

Did problem start recently or at a specific time? If so, did you make any changes to the bike shortly before the first fuse popped? If so, reexamine what you did at that time.

And add-ons? Tail light modulators or anything that tapped into the circuit?

Any modifications to the stock wiring system? If so, undo them....or undo one at a time. Or undo any that may have tapped into circuits related to running lights.

Any burnt electrical smell? Have the tank up any and move anything under there. I think I recall Skooterg's wiring harness going kerplewey over time related to under tank activity...possibly with valve checks and an intermittent connection.

the only thing tap to the electrical is an led light to my license plate

staintune007 said:

the only thing tap to the electrical is an led light to my license plate

Click to expand...

It only takes one thing and "tapping" can do bad things if not done correctly. Very few have issues with the stock wiring system and many more have issues with stuff they add.

Might help to focus in on the tap area...or try disconnecting it for a while and see if your problems go away. If so.....something ain't wired right.

Iggy's got it right. Disconnect that LED light and make sure the place you tapped it in is well insulated. If that doesn't solve the problem then follow the wires to and from each light and check for worn insulation, especially where the wires pass close to metal parts.

A bad tap can increase current draw, too, just by being a little flaky.

I put a cruise control on my bike when I got it and had weirdness with it just a few weeks later. Went through and replaced all the taps with soldered splices, not a lick of trouble in the nearly 5 years since. Nothing to do with your LED light, just an illustration of how a tap you think is OK might not be.

+1 to what others have said, except...

The running light fuse goes to the rear tail lamp filaments (x2) , the two front running light filaments (x2) in the front turn signals and the meter backlights in the instrument panel. In the cas eof an intermittently blowing fuse, I'd be suspicious that tehre is a blown light bulb somewhere in that circuit, and the broken/loose filament is moving around and shorting to some grounded structure inside the lamp. As I recall, there was someone that had such a problem a few years ago on an FJR, though I can't recall which bulb it was.

Are any of these bulbs blown? Or maybe looking like they aren't putting out the right amount of light? It's a bit hard to tell if one of the tail running light filaments are blown since they are in the same light assembly.

But, I still have to wonder, why did you need to install a plate light? In the world or electrical/electronic troubleshooting, the best logic is to usually suspect the MRFWU

This is why I always recommend against tapping into the OEM harness. The risk may be minimal with the right taps (NOT those slice-and-dice guillotine taps) but IF you're the one that gets a bad connection then the troubles can be a real PITA. Much better to use a pin extractor and add the new lead at the gang connector in the harness, get your solder on, or (if you must) use PosiTaps (since the mechanical connection is a simple pin prick that won't slice through any wire strands).

IIWM I'd remove any taps, repair that section of wire with a good solder, shrink wrap, and liquid tape. Then re-do the connection right.