Headlight Fuse Blows Repeatedly (1 Viewer)

[Drofen]

Let me preface this by saying I’m an electrical imbecile—I mean I get the concept, but things like wiring diagrams look like Norse runes to me.

On my 1984 FJ60, I swapped out my headlights with the City Racer LED kit. I was very chuffed when everything worked great!

… for about 30 seconds when I heard an electrical “pop” and the driver side headlamp went out. Checked the fuse panel, and the 10A fuse had indeed blown. Swapped it for the good 10A fuse from the other side, and it immediately popped. Went back up front, checked all the plugs, everything looked okay. Swapped in a 3rd 10A fuse, and it also immediately popped.

I’m pretty sure that the fact it worked (both high and low beams) at the beginning means it’s not a swapped plug or somehow incorrectly wired. I also never had an issue with the stock headlights (other than low light output). This line of thinking leads me to think I’ve probably developed a short somewhere, but I have no clue how to go about diagnosing such.

Any tips or strategies?

 

[MrMacdugal]

Let me start by telling you this.. I too am an electrical dunce...
I may be able to start guiding you correctly, though Unplug things in reverse order from farthest away. unplug just that lamp, new fuse, then test. Does the fuse blow? if yes, then unplug the next plug in the harness back. I'm not super familiar with the city racer kit, but also inspect it for loose pins or pinched over wires. Check all your harnesses. IF you did a lot of pulling and yanking during the install you may have inadvertently chaffed and grounded a wire causing a short.


My other revelation is this... Unplug that fancy switching device they supply you and plug it into the other headlight... IE, swap the little diode thingy's and see if your headlight problem goes to the other side. Issue isolated.

Remember, i'm no electrician. This advice was free.

 

[OSS]

Try a 15 amp fuse

 

[MrMacdugal]

I went ahead and read the guide for troubleshooting the kit that you bought. You probably have a bad switcher dealy. Try advice #B from above. De nada

 

[BigNick]

Disconnect the lights you put in one at a time and see what happens when you fuse it and power it.. my guess is one of the plugs you were jacking with has shorted.. look in the plugs for obvious things.

Maybe start with a wire diagram to figure out where to start disconnecting large sections of the lighting system to narrow it down .. disconnect replace fuse.. see if it blows.. and so on... If it's not something easy and visible for example : is there any time like seconds before the fuse blows, try to identify if there's a light out in the intervening time..

I could explain how to narrow it down with a multimeter but.. you would also need a wire print..

 

[Drofen]

As predicted above, looks like a bad switching module. New one inbound from City Racer.

 

[BigNick]

As predicted above, looks like a bad switching module. New one inbound from City Racer.

Good find..

 

[Drofen]

Update: new module from City Racer (on their dime, even a year and 3 months since purchase) and problem fixed. Thanks for everyone’s help pointing me in the right direction.

 

[BigNick]

Update: new module from City Racer (on their dime, even a year and 3 months since purchase) and problem fixed. Thanks for everyone’s help pointing me in the right direction.

View attachment 3318781

Interesting. You got 15 months out of a new one and that's it?!

 

[Drofen]

Interesting. You got 15 months out of a new one and that's it?!

Sorry, that wasn’t clear. I purchased the lights 15 months ago, just now installed them.

 

[DevonBen60]

Good find..

Could you please show a pick or share location of this switching module please?
I may have a similar issue
Thanks