Main fuse amps

[Pddain]

Ok. Looking under the seat I noticed I have an 80 amp fuse, it was missing the cover which got my attention.

Jersey Big Mike told me the biggest fuse I should have is 40 Amps. Any thing larger could really cause me an issue especially if the VR goes south.


I need some guidance here. This bike is full of surprises.

Do I swap the 80 for a 40 ? Does this require replacing the inline fuse holder ? 10 gauge wiring is in place.

Guidance would be appreciated.

 

[Pddain]

The service manual shows a 40 Amp circuit breaker and the two 20 amp fuses one for each buss. Any insight into why someone would add an 80 amp fuse?

 

[Mastiff Rider64]

The service manual shows a 40 Amp circuit breaker and the two 20 amp fuses one for each buss. Any insight into why someone would add an 80 amp fuse?

Its all they had on hand??? Not sure why you would double a fuse size. I've heard +/- 3 percent of amp rating, but double?

 

[Jersey Big Mike]

The service manual shows a 40 Amp circuit breaker and the two 20 amp fuses one for each buss. Any insight into why someone would add an 80 amp fuse?

Yeah they added the 40A + 2 20A came up with 80 and only did one fuse likely. You need to check that the buss' have the right fuses.

 

[Pddain]

Could be, surprised my 06 Mastiff doesn’t have the Circuit Breaker but has a 80 amp main fuse. Could I have a different charging system, although even an increased output from the charging system would not require 80 amp protection. I could fry the system at 60 amps as I understand it. Any thoughts.

 

[Pddain]

I will check

 

[Pddain]

Yeah they added the 40A + 2 20A came up with 80 and only did one fuse likely. You need to check that the buss' have the right fuses.

If this is true, someone needs to go back to basic circuit 101. That is scary.

 

[Pddain]

Swapping it for a 40 Amp fuse

 

[Jersey Big Mike]

Swapping it for a 40 Amp fuse

check that the other buses are fused.
The 40A fuse is to be between the VR and the Battery
Other fuse should go battery to circuits.

IE -- Do not rely on a SINGLE fuse in the system.

 

[knothead]

What im about to say is probably going to have different opinions from folks but it is what it is...

I personally have no use for a circuit breaker on these bikes...it doesnt let you know where the problems lies if and when it happens....all it does is resets itself till something burns up and it will in time with the these circuit breakers..i done away with that on all my bikes and all the other bikes i work on for people...i put the little red block in place of it.....from there i run a inline fuse to the battery with a 30amp on a 32amp charging system....on a 40 amp system i use a 40amp fuse....if the voltage regulator goes bad it will not get the ehc...from the battery i run a 20 amp fuse to the ehc to protect it from the battery incase it shorts or just somehow 30 amp doesnt blow if the voltage regulator goes nuts...so when and if the bike stalls on the side of the road i can pop of the seat and look at 2 fuses...if the voltage regulator fuse blowed them i know what happened...if the battery fuse blowed i also know there is a problem there...this just narrows down where the problem lies and everything is protected

 

[Pddain]

check that the other buses are fused.
The 40A fuse is to be between the VR and the Battery
Other fuse should go battery to circuits.

IE -- Do not rely on a SINGLE fuse in the system.

JBM. It does. I will take knotgrass advice and yours and make sure I have protection from battery to EHC.

 

[Jersey Big Mike]

JBM. It does. I will take knotgrass advice and yours and make sure I have protection from battery to EHC.

Since it does, you confirmed what I thought (whoever did 40+20+20 and used 1 80A fuse) Some people should never do electrical things.

 

[Th3InfamousI]

80 amps...might as well not have a fuse.

Where y'all getting the 40+20+20? 40 from VR to battery 20 to the EHC but where the hell is the other 20?

Sent from my moto z4 using Tapatalk

 

[Pddain]

The 05 wiring diagram shows a 40 between the battery and the VR and two 20’s, one for each bus on the EHC.
The 06 mastiff wiring diagram shows the 40 but no 20’s on the diagram that I could find. It may be in the box. If I don’t have one I will add one per Knothead’s guidance.

I am constantly surprised at what I find on this bike. We have dual grounds in there now and beefed up the wire gauge. No more signs of heat on the connectors.
We start the the exhaust and carb tuning on Friday. I will look deeper then.
sorry Knothead, knotgrass was a typo

 

[knothead]

The 05 wiring diagram shows a 40 between the battery and the VR and two 20’s, one for each bus on the EHC.
The 06 mastiff wiring diagram shows the 40 but no 20’s on the diagram that I could find. It may be in the box. If I don’t have one I will add one per Knothead’s guidance.

I am constantly surprised at what I find on this bike. We have dual grounds in there now and beefed up the wire gauge. No more signs of heat on the connectors.
We start the the exhaust and carb tuning on Friday. I will look deeper then.
sorry Knothead, knotgrass was a typo

Lol all good

 

[Pddain]

Where y'all getting the 40+20+20? 40 from VR to battery 20 to the EHC but where the hell is the other 20?

Sent from my moto z4 using Tapatalk
[/QUOTE]
ok, I am learning, so cut me some slack. 05 service manual page 6-54; the diagram shows battery power going through A3 into the EHC. There is a symbol at the input to each bus in the EHC I misinterpreted as a fuse but is inside the EHC and is a varistor ( type of resistor for us students) with a 20 next to it I thought was Amps. Sorry for taking everyone down a rathole. I haven’t found a fuse on the diagrams between the battery and the EHC, so per Knothead’s advice, I am going to add a 20 amp fuse in that circuit.

 

[Th3InfamousI]

ok, I am learning, so cut me some slack. 05 service manual page 6-54; the diagram shows battery power going through A3 into the EHC. There is a symbol at the input to each bus in the EHC I misinterpreted as a fuse but is inside the EHC and is a varistor ( type of resistor for us students) with a 20 next to it I thought was Amps. Sorry for taking everyone down a rathole. I haven’t found a fuse on the diagrams between the battery and the EHC, so per Knothead’s advice, I am going to add a 20 amp fuse in that circuit.

Yea, I was just curious where this extra 20 was coming from but makes sense now. Wasn't sure why nobody asked, but just wanted to make sure you got it setup right.

They originally never had any fuse going to the EHC as it's technically integrated internally.
However that is via those veristors/relays, which overtime will fail as they automatically reset and would continuously cycle on/off with an issue going on. So rather than wearing out relays in a box you can't fix the external fuse will help reduce that impact to the box, and ease of troubleshooting.

A lot of benefits out of a few bucks for an inline fuse.



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[Jersey Big Mike]

Varistors are meant to clamp the voltage at a maximum level.
They are typically used in Surge suppressors in power strips.
The problem is that they are sacrificial components with NO WAY TO TEST IN CIRCUIT.

A varistor will be burnt out and your indicator that you are protected will stay lit -- major flaw when used in surge suppression for electronics.
If anyone is interested I can expand upon this as I did a lot of research back in the day into the topic.

 

[Jersey Big Mike]

Also looking at the schematic I have, bus 1 and bus2 and solenoid all have devices on them with the same symbol.

That is NOT a VARISTOR. The symbol is similar but now correct and wired that way it would do NOTHING, The bike would NEVER EVER even start.

 

[Pddain]

What im about to say is probably going to have different opinions from folks but it is what it is...

I personally have no use for a circuit breaker on these bikes...it doesnt let you know where the problems lies if and when it happens....all it does it resets itself till something burns up and it will with the these circuit breakers..i done away with that on all my bikes and all the other bikes i work on for people...i put the little red block in place of it.....from there i run a inline fuse to the battery with a 30amp on a 32amp charging system....on a 40 amp system i use a 40amp fuse....if the voltage regulator goes bad it will not get the ehc...from the battery i run a 20 amp fuse to the ehc to protect it from the battery incase it shorts or just somehow 30 amp doesnt blow if the voltage regulator goes nuts...so when and if the bike stalls on the side of the road i can pop of the seat and look at 2 fuses...if the voltage regulator fuse blowed them i know what happened...if the battery fuse blowed i also know there is a problem there...this just narrows down where the problem lies and everything is protectedView attachment 92210View attachment 92211

Ok, I have the little red block, with a 40 Amp inline fuse running from the red block , on the red wire to the battery. Good news is the 80 amp is gone, the 40 amp is in just where Knothead told me to put it. I have the wire with the yellow insulator that I assume runs to the voltage regulator attached to the little red block See Knothead’s pic above. Surprising, I have a third wire coming off that same red block going to one of the power harnesses plugging into the EHC. The 06 Mastiff drawing shows that wire as part of the starting circuit. I had to knock off tracing wires today but will continue later. Good news is No circuit breaker any where, yea and the proper 40 amp fuse is now installed between the battery and the little red block isolating the VR. If I pull the 40 amp fuse, I kill power to the EHC which I am not convinced should happen but it does. Thanks for everyone’s input.