angus99
Guru
One of the bilge pumps on my DF 44 was working perfectly until it stopped. When I put a meter on the circuit, it was only getting 3 volts. What's the most likely cause, circuit breaker? Thanks.
. . . What's the most likely cause, circuit breaker?
be suspicious of any lump wrapped in electrician's tape.
I suspect bad connections to the float switch or the pump. Either way poking meter leads into unknown wires can give false readings.
Bill
I must not be understanding. Would there not be 12 volts across the two wires feeding the float switch? .
Not if the float switch is on the negative side of the pump? There are too many variables here, take the entire lump or group of wires apart. Find the +12 VDC plus and the -12 VDC or negative. Start from there and then check continuity through the float switch.I must not be understanding. Would there not be 12 volts across the two wires feeding the float switch? If I probe the wires upstream of the float switch, wouldn't that take a faulty switch out of the picture?
I do plan to replace punctured wires.
I must not be understanding. Would there not be 12 volts across the two wires feeding the float switch? .......
I agree Ron the circuit isn't that complicated.If everything else is working and wired properly, you should read 12 volts across the float switch when it is in the "off" position and zero volts when it is in the on position.
Trying to read the voltage across the switch tells you nothing.
The bilge pump circuit is no different than a lighting circuit. Power is supplied from the positive side battery through a fuse or circuit breaker, then a switch, the pump motor, and back to the negative terminal of the battery. There may be more than one switch. A power switch and a float switch.
I was putting the probes on the two switch wires, but was getting only a couple of volts whether the switch was on or off.
In any event, I'm having other work done at a yard and will have the electrician have a look. I'll post whatever I find out.
Thanks for the great feedback.
That will tell you nothing about voltage to the pump. Both those wires are hot or positive wires. One should have power to it at all times and the other only when the switch is on. You test those by grounding the negative probe and checking each switch wire with your positive probe.
You need to get a book on basic marine DC and AC systems before you try to test anything else. So you'll know and understand what you're doing.
Hey, Bill, thanks for the lecture! I'll certainly keep those books in mind to add to the 3 on 12-volt DC I already own.
It turns out the two primary wires feeding the bilge pump and switch are, in fact, positive and negative, exactly as they appear to be. The reason the pump stopped working is that the PO wired it to an unmarked breaker that someone had shut off by mistake. I didn't notice it had been switched off, which was clearly my mistake.
Sorry to waste everybody's time on this but I do appreciate all the constructive feedback.
It wasn't intended as a lecture. It was just based on your posts it sounded like you were unsure of what you were doing and how you should do it. So I was merely suggesting you do some research before you come to any incorrect conclusions as to what the problem was.
Glad it turned out to be something simple.
Should a bilge pump even be on a switched source? Fuse protected for sure but not switched.
Actually switched, no unless it's a spare crash style pump with no float switch. However it's something my surveyor and I caught during my Gulfstar inspection. Somehow for the last 35 years this got past everyone it was the factory wiring for the bilge pumps and it was wrong. It's been corrected it's also something the insurance company wanted corrected immediately. I installed a 2 bilge pup unit that counts daily, weekly and monthly cycles of both pumps. It is now powered directly off the fused but non switched DC mains. It protects both pumps and wire via re-settable individual push button breakers and allows over riding the float switches if needed. The unit's made by AC DC Electronics Inc.Should a bilge pump even be on a switched source? Fuse protected for sure but not switched.
Sorry if I over-reacted. It's been a stressful couple of days. I appreciate your intent.