Fuse replacement

[wildziner]

I think I blew the 12V adapter fuse on my 08 speedster 150 while trying to plug in the air inflator I bought this weekend. It worked for a few seconds, then shut off. It works when I plug it directly onto the battery terminals, so I know it's not the inflator. I can look around for the right blown fuse, even though it's not technically labeled (I'm assuming it's the one called accessories located in the driver console), but my main question is do you really have to replace that fuse (10A) with another 10A like the manual says, or can you put a 20A or 30A there so it wont blow again? It'd be a lot more convenient to blow the tube up from the 12V adapter than taking all the stuff out of the back, putting the storage tray on the boat, and connecting it to the battery while we're out on the water. I'm thinking the battery must be able to handle the additional load, but maybe the wiring is only rated for 10A?

Elementary to most of you, I know, but any help would be much appreciated . . .

 

[Gunsrunner]

Wire Gauge Recommended
Maximum Fuse Size
00 awg 400 amps
0 awg 325 amps
1 awg 250 amps
2 awg 200 amps
4 awg 125 amps
6 awg 80 amps
8 awg 50 amps
10 awg 30 amps
12 awg 20 amps
14 awg 15 amps
16 awg 7.5 amps
These are the recommended maximum fuse ratings for the corresponding wire size. Using a smaller fuse than what's recommended here will be perfectly safe.
Wire:
As you already know, wire comes in many different styles and sizes. I will touch on a few design parameters that you must consider when choosing wire. The most important consideration is the amount of current that will be carried by the wire. The wire's size is indicated by gauge. The most common wire sizes used in car audio range between 4awg and 22awg. The larger the awg (American Wire Gauge) number, the smaller the wire size.

Resistance:
We already discussed resistance. Now you need to realize that all wire has resistance. This is the reason that wire has current limitations. If you remember the formulas from Ohm's law, you will remember P=I^2*R. The power dissipated in wire will be in the form of heat.

For Those Who Refuse to Fuse:
Now let's see what will happen if excess current is passed through a small conductor. We will assume that some imaginary piece of wire (we don't want to destroy a real piece of wire) has .01 ohms of resistance (e.g. a 15 foot long piece of 8 gauge wire) and that wire is connected directly to the positive terminal of the battery (without a fuse... that should scare you). Now let's say that the other end of the wire is allowed to touch to the chassis of the vehicle (which, in most vehicles, is connected to the negative terminal of the battery). The two battery terminals are basically shorted together by the wire (through the chassis). In this situation, a very large amount of current will flow through the piece of wire.

If we wanted to calculate the current flow through the wire, we would use the Ohm's law formula I=E/R. If we use the ideal automotive battery, which is rated at 12 volts, and divide it by the resistance of the wire which is approximately .01 ohms, we get a current of 1200 amps.
I = E/R
I = 12/0.01
I = 1200 amps


Then plug the current into the formula P=I^2*R. We get:

P = I2*R
P = (1200*1200)*0.01
P = 14,400 Watts


This shows that the wire would dissipate 14,400 watts of heat which would melt the wire's insulation and more than likely ignite everything that comes in contact with the wire (fuel lines, other wires, carpet, plastic, insulation). In comparison, the largest burner on your electric stove will not put out that much heat on high!

 

[wildziner]

So the worst that could happen is that my boat will be engulfed in a fiery explosion, blowing bits of sea doo and me all over the water . . . hmmm, I think I'll give it a try!!!!

I'll look to see what the wire gauge is, and put the corresponding fuse there, but I assume BRP has already done that, and I'll have to live with connecting straight to the battery, or replacing that wire. I'll also take a look at the manuals here to find the wiring diagrams . . .

Thanks

 

[sanpan25]

So the worst that could happen is that my boat will be engulfed in a fiery explosion, blowing bits of sea doo and me all over the water . . . hmmm, I think I'll give it a try!!!!

I'll look to see what the wire gauge is, and put the corresponding fuse there, but I assume BRP has already done that, and I'll have to live with connecting straight to the battery, or replacing that wire. I'll also take a look at the manuals here to find the wiring diagrams . . .

Thanks

Dont connect straight to the battery, if you need put in a fused or circuit breaker (resetable) power point with appropriate wire size and connection points. Overtons catalogue has some of this stuff, so might an auto parts store, or someone who does sound system installs.

PS Circuit breaker being resetable will be best so if you are out and it pops for whatever reason let it cool off and ready to go again.

 

[kustomkarl]

:agree: Do Not hook direct to the battery without an inline fuse in place. Talk about a shorted wire and possible fire...Got Boaters Insurance?

Karl

 

[wildziner]

Insurance I got - not much good if I burn one of the kids arms off though . . . we're not planning on going tubing for a few weekends now with our schedule, but when I have time, I'll look at the gauge wire, and see how hard it might be to replace. If hooking to the battery, I'll definitely get an inline fuse before I try any of this. The 2 seater tube I got is too big to fit in the boat (and be able to see clearly enough), so I may try blowing it up before going out, and then hooking to the back of the boat with that suction kit I've seen.

 

[kustomkarl]

Craig, just kidding about the insurance...Use at least 14 or 16 guage wire with a in-line fuse... Here is a sceret....go to Radio Shack and tell them what you want to do. What amp draw does the compressor use? You could bring it with you and tell them what you want to do. Wire the plug extension direct to the battery with the resettable fuse. Under the seat install the plug connection in the compartment for easy access.( you need to have the connection within 12" of the battery for safety of the fuse. Lift the seat remove the cover and plug it in...pump up the tube.

Been there done that ...I own a Kustom vehicle conversion company for 22 years.

Karl

 

[wildziner]

when we bought it, the tech guy at the dealership told me it's pretty hard to reattach the seats, because they have the same threaded plastic tabs that hold cars' ground effects? I've seen the long white ones sticking out of only one of the seat backs, but I havent poked around enough to see how the others (or the bottoms) are.

 

[kustomkarl]

I haven't see your seats up close...on my 200 speedster the seats are held on by 2 snaps to keep them from flying out, under each seat is a compartment for storage. Under the rear seat on the drivers side is the battery. Just look for a location to mount it where it will be dry and out of water spray.

Karl