Blowing Fuses

[flyin]

after the ride over to featherston, as i was leaving the carpark in l/hutt it was pointed out to me that i had no lights on the back!!!

i had a headlight but no tail/brake light and no display lights (who needs to know how fast ur goin u say?........)

well i rode home from the hutt, following someone i kinda hoped wasnt speeding..... then pulled the farings off so i could get to the fuse box.
sure enough the fuse for the tail light was blown.... no biggie but when i replaced it and turned the bike on to see if it was all good. i see a flash and hear a click and its blown...... try it again and the same thing happens soooo

im guessing maybe regulator??? how do i check this? what else could it be??

[Cajun]

after the ride over to featherston, as i was leaving the carpark in l/hutt it was pointed out to me that i had no lights on the back!!!

i had a headlight but no tail/brake light and no display lights (who needs to know how fast ur goin u say?........)

well i rode home from the hutt, following someone i kinda hoped wasnt speeding..... then pulled the farings off so i could get to the fuse box.
sure enough the fuse for the tail light was blown.... no biggie but when i replaced it and turned the bike on to see if it was all good. i see a flash and hear a click and its blown...... try it again and the same thing happens soooo

im guessing maybe regulator??? how do i check this? what else could it be??

put a bigger fuse in and try again want at least a 15 amp i would be putting a 20

[FROSTY:Me]

ya need the correct size fuze for sure--but if its doin what you say--its a big chance you have a short in the system--se the thread about street majic wiring

[Paul in NZ]

Mate its a simple lighting cct. Putting a bigger fuse in it is not a good idea.

First thing I'd do is identify all the devices powered off that fuse. If it's just lamps, remove the globes and try it again. If it blows there is a contact or a short cct some place in the harness. Give it the old eye ball treatment.

If it does not blow, inspect the bulb holders and replace them 1 at a time until you find the dud.

Try that and then we can graduate to shit like multimeters

Paul n

[Cajun]

Mate its a simple lighting cct. Putting a bigger fuse in it is not a good idea.

First thing I'd do is identify all the devices powered off that fuse. If it's just lamps, remove the globes and try it again. If it blows there is a contact or a short cct some place in the harness. Give it the old eye ball treatment.

If it does not blow, inspect the bulb holders and replace them 1 at a time until you find the dud.

Try that and then we can graduate to shit like multimeters

Paul n

Paul i had same problem with my 96 zzr250, blowning fuses all the time for rear light, put a nice big fuse in there, and never had a problem again, never in its 50,000kms life i had it did i have any electical issues, other than one above, always ran like clock work, even when i striped it down to repaint it, and check everything, there was nothing wrong with harness or earths

[flyin]

yeah didn't want to reach straight for the 30amp fuse!! wen i put the new 10 in and turnd the key it blew instantly! i know they are there for a purpose too........

inspected the tail light, looks like i might have already blown it (only been in a month!!)
ive gotta go buy some more fuses before i can do more curciut testing so will replace the bulb too and see if we're in luck......

cheers

[Redstar]

I would suggest that you dont up the fuse because you will reach a point whereby the fuse is rated at the same current capacity as the wireing and when things get really interesting as the wiring loom starts to melt. its reassuring that the same fuse blows and its not a random act, there is clearly a problem with this circuit and the fuse is only doing what it is designed to do "blow" now there is likely to be a high resistance in the circuit so you need a meter to measure the ohms and first measure the ohoms of the bulb removed this is the base measure now install the bulb and measure the ohms from the fuse output side to earth this will be a tad more as it accounts for the ohms of the wire to the bulb and to earth.
if the resistance ohoms is increased greatlly say 1 ohm more you have a high resistance circuit pulling a higher current and blowing said fuse.
power is watts and the bulb is say 5 watts , watts are a unit of power
now current amps a power divided by volts say 13volts so 5 divided by 13 = about 0.4amps allowing for circuit resitance say 0.5amps now the fuse is usually rated a tad higher to allow for peaking so a 1 amp fuse would be normal if there are two 5 watt bulbs perhaps a 2 amp fuse would be used.
now if you put in a 5amp fuse power = v x I and thus now 13 x 5 65 watts of power in the circuit intended for 10 watts hello bulbs blow history if your lucky
the wire that feeds the bulbs is a sort of fuse if you exceed the current rating of the wire the wire will melt. Hello MELT DOWN!
there are two likely causes of your problem. 1 high resistance 2. excessive output votage from your regulator. dont up the fuse it will cost you in the end.