Quick Bilge Pump Fuse Question

[_Ish_]

The float switch is busted on my RuleMate 500gph 1.8a bilge pump and I have two different replacement pumps, one of which I'll use now and the other I will wire in at a later date. They both require a 5a fuse. The fuse size that was in the factory switch when I bought the boat is 3a and that is what I have always replaced it with. Can I straight swap a 5a fuse in its place? The wires are 600v which is the same as the wires that came with both new bilge pumps. I am very much at the beginning stages of learning wiring/electrical work and one of the things I read about swapping a 3a fuse for a 5a is that the switch itself needs to be rated for the increase. But the switch doesn't have any spec info.

New pumps:

Maxzone Auto Bilge Pump
1100 GPH
12v 3.2amp
5.0 amp fuse

Seaflow Auto Bilge Pump
750 GPH
12v 3.0 amp
5.0 amp fuse

Any advice would be greatly appreciated. I have a 3 month hitch starting in a week and need to get an auto bilge pump functioning.

 

[bigd14]

You probably can. The 3 amp fuse will blow with the new pumps. Check the bilge pump switch to make sure it is rated for 5 amps (or more). If it’s rated for less than 5 amps, replace the switch.

The question I have is why have you needed to replace the 3 amp fuse? A blown fuse means a problem somewhere in the circuit, maybe a loose connection or corrosion or the current draw is higher than the fuse rating. Under normal circumstances fuses should not be blowing. I would want to chase that problem down before proceeding. Might be worth replacing the entire wiring run from fuse panel to pumps while you are at it.

In general, fuse to the wire size unless there is a device that requires a smaller fuse. The chart on this page is helpful: https://www.bluesea.com/articles/1441

 

[_Ish_]

Check the bilge pump switch to make sure it is rated for 5 amps (or more). If it’s rated for less than 5 amps, replace the switch.

Thank you for the response. My issue is that I don't see any kind of rating (or info at all) on the switch. It's presumably the original one and I was hoping someone here might know what the rating is for an '81 25+.

Regarding blown fuses, I've replaced it 3 times over 18 months and it is wired directly from pump to switch to battery. Unfortunately, I likely won't have the time to redo all the wiring before I ship out, but I'll be cutting back wire as far as the already attached wiring on the new pump allows. Based on the previous things I've seen, it is likely that the PO did a slapdash job connecting the pump to the wires coming out of the switch.

EDIT: perhaps this isn't original since it says "Rule" on it. Picture attached.

 

[bigd14]

That switch will handle up to a 20 amp fuse.

Rule 3-Way Panel Lighted Switch | Xylem US

www.xylem.com

Hopefully the fuse blowing is being caused by the old pump you are replacing. If it continues you’ll need to replace or repair the wiring, the switch, or both. But to answer your original question, you will be fine with a 5 amp fuse in the switch fuse holder for the new pump.

 

[_Ish_]

Thank you so much for this help. I've been really stressing about leaving my boat for 3 months without a bilge pump I can rely upon. Was worried if I threw in a 5a, I'd get a call that it burned down.