FW pump fuse

[rwc]

My FW pump failed so I switched to a bigger one because bigger is better, right?!

Now it runs for a few minutes before popping the fuse. I’m assuming I need a bigger fuse for the higher power pump?

The fuses are little red push button types under the dash. Can someone tell me the proper name for them and where I might find them?

[mmwjr]

That would be a circuit breaker. What is the current draw of the new pump and what is the amp rating of the breaker. More importantly what is the wire size from the breaker to the pump? The breaker cannot be rated larger than the wire can handle otherwise it can catch on fire.

[rwc]

Ah, of course. Circuit breaker. The cable from the breaker to the pump is heavier than the pump leads by at least one size, so they should be fine. Unfortunately, the old leads were about six inches longer than the new ones, so I’ve got six inches of the lighter size (one size down) from the old pump patched in temporarily to test it. I will replace that section, particularly if I have to up the breaker size.

I think the pump draws 6amps, so breaker of 8 maybe? I’m guessing the current one is 5amps. All the breakers are in a panel just under the dash.

[mmwjr]

The new pump should have paperwork to tell you what size of fuse/breaker to use. Needs to account for inrush current when it first turns on.

[shrew]

1) Measure the distance from the fuse bus to the pump.

2) Multiply the value from step #1 number times 2 (2x) to get the total distance of the circuit.

3) Verify the amp draw of the pump.

4) Size the wiring for the amp draw based on the product (distance) from step #2.

5) Install a fuse that matches the amp draw of the pump.

A circuit should not really have 3 different sized wires in the circuit unless all the sizes are equal or greater than these calculations. Make sure you'r using marine shrink crimp connectors and tinned wire.