subject of 30 amp fuse

[andy york]

having read all the posts on melting the 30 amp fuse...I guess I am still confused as to

what the actual problem really is.

I know Docc wired in a 30amp fuse separate from the fuse block. I have an extra 30 amp in line fuse

but I am not crazy about the idea. The aftermarket 30 has #10 wire and the Italians put # 10 or # 12

wire on the bike. In my mind you are just moving the area that might melt and cause problems

further into the wiring harness.

I have a fairly new alternator,voltage regulator,extra grounds for lots of things.....so now at 94,000m

why am I now having problems with the 30amp fuse?

bike is apart so it's easy to check things...so give me you best insight

 

Andy

[Kiwi_Roy]

When you say the fuse melts I assume you mean the plastic melts rather than just blows.

This is caused by a bad connection between the fuse holder and the fuse, to fix this you need to clean the contacts and try to apply some more pressure

by bending the prongs so the fuse is gripped tighter.

[andy york]

I misstated the stock wire size in my first post.The stock wire appears to be 16 gauge...whatever the metric equivalent is.

So ...coming out of the voltage regulator there are 2 red wires tied together that look to be 16g.this paired wired plugs into

a single green/red stripe that travels to the fuse block at the 30 amp fuse. The other side of the 30amp fuse is a red wire

that goes to the battery.

My problem is wire gauge. Where I come from if you pull 30amps through a piece of 16g....it will work for bit but will get

hot and melt and start a fire or blow a fuse. maybe i'm mixing up my AC and DC power flows...i dont know.

My alternator and voltage regulator are only 2 -3 years old.

the fuse was deformed a bit ....it had been hot but did not blow...and the fuse block and wires appear to be OK.

Reguardless...My solution is to Run 12G wire from the battery to a inline fuse holder at the front of the bike

and then connect to the double red leads out of the voltage regulator.

So far the bike runs ok on the stand...just need to get all back together and go for a ride.

I will agree that a lot of times there are bad connections and loose wires. I don't believe that is my problem.

We shall see.

[AndyH]

My solution is to Run 12G wire from the battery to a inline fuse holder at the front of the bike

and then connect to the double red leads out of the voltage regulator.

When you fit the Electrex 451 replacement regulator the manufacturers recommend running a big fat wire directly back to the battery from these two red wires. I got a maxi blade 30 amp fuse and holder and wired it between the battery and those red cables with a fat 27amp rated cable (we don't seem to use 'gauges' of wire over here) using soldered connections and it seems to do just fine.

 

If I get round to fitting an OEM regulator again one day I'll probably keep this solution as other posts suggest this (along with good earthing) is a 'good thing'.

 

AndyH

[Kiwi_Roy]

The Ducati regulator puts out high current half wave pulses probably well over 30 Amps so any resistance at all causes heating.

(Watts = Current squared X resistance)

The fuse holder may look OK but it will benefit from cleaning and tightening the contacts.

 

The fuse on mine welded itself to the holder and the plastic melted but since cleaning is has been ok.

 

The alternator doesn't put out a full 30 Amps for very long, the peaks are just as high but it starts to skip pulses

as the battery Voltage comes up so the average is about 9 - 12

[andy york]

headed up to Indy this morning. Need to survey a job so I thought I would ride up.

Was almost to Bowling Green and she coughed twice. Felt like I had hit the kill switch

for 1/2 sec ...did thet about three times.

Filled up with fuel ( 4 gal ) and turned back to home.

did not miss a beat on the way home and I was running even harder coming back.

I hate not having confidence in my gal.

Fuse was not hot ....regulator was not hot ...battery was not hot ...

oh well back to the drawing board as they say

 

andy

[Kiwi_Roy]

I mentioned in a PM that the ignition switch contacts can cause the ECU relay to drop out if they are really dirty, the grease goes quite stiff after a few years and tends to hold the contacts apart, its worth flicking the switch a few times to see if it improves. I caution against using solvents to clean switches, better to take them apart and clean out the old grease replacing it with good old petroleum jelly aka Vaseline.

 

For those with lots of tupperware the health of the contacts can be checked from under the seat, it should be consistent and

Just find where the wires terminate and pull the fuses / relay and measure from there Fuse 3. Fuse 5&6 and relay 3 in this case

Otherwise it's quite easy to pull the contact block off for servicing.

 

This is for a V11 Sport but other 2000 era Guzzis are very similar, just trace where the wires go from your schematic or Carl Allison drawing.

You will notice that it goes through a 4 way connector (under the tank I think)

 

Test Point Layout.pdf

 

Don't forget the side-stand switch has been known to bounce open which also drops out the ECU.

[andy york]

I now have the ignition switch contacts nice and clean, lubed with vaseline, back together.

we will have to await the outcome of a nice little test ride.

This is to me the nice and wonderful thing about this board.

I consider myself a pretty good mechanic, but once you have done

all the logical things to solve a problem and nothing works, you can come

here and read up on things and find out about the flukes that happen.

anyway ....good on everybody and their associated wisdom.

thanks

Andy

[tattootim1]

I now have the ignition switch contacts nice and clean, lubed with vaseline, back together.

we will have to await the outcome of a nice little test ride.

This is to me the nice and wonderful thing about this board.

I consider myself a pretty good mechanic, but once you have done

all the logical things to solve a problem and nothing works, you can come

here and read up on things and find out about the flukes that happen.

anyway ....good on everybody and their associated wisdom.

thanks

Andy

 

 

+1 had the bullet conectors play up Thanks everyone

[Kiwi_Roy]

Intermittent faults can be hard to pin down. I often suggest adding a small lamp to the circuit which allows you to safely monitor for loss of power.

As long as the ECU relay is getting power the bike should run, if it starts to falter a glance at the lamp will tell if it's something dropping the relay out.

This applies to pretty well any of the early Guzzis with fuel injection, the wiring around the ECU and coils etc is pretty much standard.

(they vary around the sidestand switch and Start relay / headlight relay)

 

The carb models too you can monitor with a lamp connected to a point in the ignition circuit.

 

If it falters and the lamp is flickering then you select a point further back towards the supply fuse and try again.

Small 12V LEDs are perfect for this, they respond quicker and are more rugged than the incandescent variety.

 

Test Lamp.pdf

[thebronze]

Andy, any updates on your hiccup? My bike continues to hiccup after its warmed up. I'd sure like to know if its electrical or fuel related.

 

During last nights ride I pulled up at a stop sign. I went to pull away and the bike coughed and almost died on me. I rev'd it up and drove off but I noticed when it coughed the charge light came on and the bike seemed to die a little as if the bat was dead. I have been thinking this is a fuel problem but she's fresh out of the shop and exhaust gas analyzed. I have a fat ground on the regulator body to the alt cover. Fresh fuse on the charge circuit. The old one was half melted from the heat. Maybe the regulator is going bad.

[Kiwi_Roy]

I'd sure like to know if its electrical or fuel related.

 

My little trick 2 posts back will eliminate half of the wiring from the equation.

 

Re 30 Amp fuse

Some Guzzis have the regulator wired direct to the battery without a fuse, the current will not go over what the alternator is capable of and won't flow back from the battery through the diodes inside the regulator.