What blows fuses?

[katman]

I have wired in a new digital instrument panel and the headlight fuse keeps blowing??

I am a wiring ignoramus so I am looking to this fine group of professionals for help.

The fuse doesn't blow right away but shortly after the bike is started and reved up.

Any ideas??

Oh yeh, I found the coils were arcing to the frame as well. Fixed that, could that have been contributory to the headlight fuse going?


Cheers,

[BassCliff]

Cooking with electrons

Hi Mr. katman,

I'm sorry to state the obvious. Too much current blows fuses. Something is drawing too much juice. A short to ground is usually the culprit. Check for bare, worn wires touching the frame. Make sure all of your electrical connections are clean. Good luck chasing gremlins.


Thank you for your indulgence,

BassCliff

[Redman]

What bike? THe Kat in your signature?
Duh... well, I could guess that "KatMan" is refereing to a Kat. Okay.
Dont know if the Kats have the glass tube or the plastic tab type fuses.

A short to ground (a positive wire comming in contact with negitive wire or frame ground) would blow the fuse immeadiatly, and blow it completly out, molten fuse wire about vaporized and glass blackened. So if something was miss wired (a positive wire hard connected to a negitive wire) the fuse would blow immeadiatly when power applied to that circuit.
Other possiblity of a short to ground may be that things are wired properly but somewhere a positive wire has the insulation worn away and on some occassion (vibration, or turn handlebar, or hit bump) that bare spot then touches the bike frame, poof.

If things wired properly (positive to positive, and negitive to negitive) and then if the load is just too much for fuse, then fuse may blow after a few seconds or maybe a minute, and the fuse just sorta melt.
I have a hard time thinking that someting in a "instrument panel" would draw too much current for the headlight fuse (or any other fuse for that matter), well, unless you got lots of other stuff added on that fuse (Other lights?). Or other possibility would be some problem internal to the instrument panel.

Let us know what bike, and maybe someone more familiar with the wiring of that model can state the various color codes of the wiring, and can compare that to anything further you can say about how you wired in this instrument panel.

.

[Steve]

If it is only the headlight fuse that blows, it at least narrows down where you have to look.

The only items that are powered by the headlight fuse are the headlight, instrument lights and the tail light.
If you have running lights in the front signals, they will be powered by that fuse, too.

.

[uudfourty]

Only drunken sailors blow fuses.

Fact.

[chef1366]

Unplug the headlight and with a multimeter on D/C and set on 20V put the postitive lead into the low beam. Start the bike and check the readings. Do the same with the high beams and then the ground to see if there is a short on the ground. If the ground shows volts chase down that short from there. If the high or low beam spikes than I'd say R/R.
Are you using the right amp fuse?

[C.V.]

Only drunken sailors blow fuses.

Fact.

you beat to it ya big jerk! I was gonna say cheap hookers though...

[argonsagas]

I would look for the simple things first.

Obviously, there is an overload and it causes the fuse to blow.

If nothing else has been changed then it would seem that the problem is inside the new digital equipment.

This could be an internal circuit fault, (and that may still be true) but since you say the fuse blows after the bike is started AND revved up, it is reasonable to look for something affected by vibration.

This could come from a loose connection of the wires feeding the panel and other parts that causes a surge, (probably external), but it could also be as simple as a faulty wire, a broken bulb or bulb connector that is intermittently touching a side panel and grounding the circuit.

[katman]

All good stuff thanks,

82 katana, new wiring harness, all wires coming from digi clocks are mini plugs.

The only wire in question is plugged at one end and the other goes to bat/ground, switched power which I took from the stock instrument light power source.
I wired a stock connector plug into the new clocks with shrink tube.

I will try everything suggested, thanks again.

[80GS1000]

If your harness is like mine there's a brown wire with a female bullet connector that isn't connected to anything in the headlight shell. It's for accessories and is switched by the ignition key. Try hooking up the power source for the digital dash to that brown wire. Then tap the ground wire for the clocks to the ground on the headlight. That's how I wired my Acewell and it works great.

[katman]

I do have a brown wire too. I am using the grey wire that is used for the instrument lighting and grounding to bat/neg.

[katman]

Put the stock clocks back on and everything is fine so its down to the power wire for the digi's.

I guess I will try another switched source for the power.

[80GS1000]

Put the stock clocks back on and everything is fine so its down to the power wire for the digi's.

I guess I will try another switched source for the power.

Try that brown wire.

[chef1366]

Use a relay

[katman]

Try that brown wire.

I believe the brown is for running lights as the kats don't have them with stock signals but can be done with three lead signals and the brown wire.

I also believe the brown wire is on the same fuse as the one I am using. I will try a diff switch wire and if not it will be time for a relay.

Chef... I will check out your diags thanks.