Boomslang Harness Headlight Fail

Al2O3 said:

I'll have to modify it.
If both headlights on main beam pull 8 amps why have they put a 40amp fuse in it?
Im off to bed nobber, I'm falling asleep here

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Its possible that when you use the full beam flash both full and dip are on at the same time, even so it still wont pull 40 amps. 40 amps is more like 510 watts at 13 volts!

The Boomslang looms are just the cheap Chinese relay looms that have been available for years on eBay for about a fiver, reboxed and sold at a premium. The build quality is poor - I’ve had crimps fail and one wired wrong so the main beam flash didn’t work.

A much better option is the Landreizger one, or make your own as suggested above. The Landreizger one has two separate fuses so you don’t get left with no lights if one blows.

40 amp fuse for a dead short, that might not pull 40 amps but a fuse is a fuse.

Worth knowing even though it has a 40 amp fuse, most std lucar terminals can only handle a constant load of 18 amps.

windy81 said:

40 amp fuse for a dead short, that might not pull 40 amps but a fuse is a fuse.

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So when the wiring melts to the point where there isnt mush left of it the fuse blows?

a case of ass covering, "well sir, we did install a fuse!"

lynall said:

Worth knowing even though it has a 40 amp fuse, most std lucar terminals can only handle a constant load of 18 amps.

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Indeed, but you still want the fuse to be the weakest link, if you have 18 amp terminals you dont want the fuse spec to be anything above that.

windy81 said:

a case of ass covering, "well sir, we did install a fuse!"

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I wonder if these harnesses meet vehicle build regs, I cant see it myself.