Wiring Problem. Weird???

cgarrad

I have a 2001 Honda Pantheon.

It blows the 20A fuse that powers the stop/tail lamp, horn, indicators, gauges and instrument lights.

The starter motor is not on that circuit and still works after blowing the 20A fuse on the other circuit.

This is the wiring diagram from Honda. I can't find a proper wiring diagram anywhere.

http://www.lingshondaparts.com/honda_motorcycle_parts_large_image_M50.php?block_01=13KEYWI1&block_02=F__2800&block_03=2748

two wheels good

When does it blow? As soon as the bike starts?
Try disconnecting as much as possible and then again reconnecting each item until the fuse fails again. Do you have an electric choke on that model?
Check connectors aren't loose and wires aren't frayed

KealanOCarroll

My hornet 250 was blowing the fuse for horn / brake / tail / indicators

The Horn draws a lot of current seemingly. Disconnect it and see does the fuse still blow, if it does, go to Maplin / Motor Factors and get a 12v relay, then use that to control the horn

cgarrad

Blows as soon as the starter motor turns.

Will disconnect everything on that circuit but since another circuit is blowing it, it would be unusual

Still worth a go.

As for the horn its just a standard one not one of the higher drawing airhorns.

Stainless_Steel

The horn only draws current when it sounds so you can rule that out.

KealanOCarroll

Have you WD40'd the whole lot ?

A surprising amount of elec issues will be solved be soaking the whole jaysus lot in WD !

I'd consider running a wire from the battery directly to the starter solenoid, if the motor turns OK then its a wiring fault rather than the motor itself

two wheels good

KealanOCarroll wrote: »

I'd consider running a wire from the battery directly to the starter solenoid, if the motor turns OK then its a wiring fault rather than the motor itself

That's a useful test.

Also, disconnect the starter motor and press the starter button.

Disconnect the low current to the solenoid switch and try it. (The starter motor won't operate.)

Consider the starter button too. Some bikes have an interconnection to cut the headlights on the start button. To exclude the starter button run a lead from the battery to the low current side of the solenoid.

I realise it seems a bit scatter gun but at some point the fuse won't blow. Pls report back with the solution cos I'm very curious now

KealanOCarroll

two wheels good wrote: »

That's a useful test.

Also, disconnect the starter motor and press the starter button.

Disconnect the low current to the solenoid switch and try it. (The starter motor won't operate.)

Consider the starter button too. Some bikes have an interconnection to cut the headlights on the start button. To exclude the starter button run a lead from the battery to the low current side of the solenoid.

I realise it seems a bit scatter gun but at some point the fuse won't blow. Pls report back with the solution cos I'm very curious now

+1 on all of these.

The fuse is blowing because something, could be anything, along the line is shorting, you have to start at one end and just work your way along the circuit until you eliminate all of the possibilities