Bilge power

[azindianrider]

so what I thought was a simple bilge pump swap has become more interesting. I have an 89 380 and as typical the wiring was onesplive after another. so while I was working om it I thought I would get back to the original. OK so I have a black (ground I assume) and two thick brown wires (one auto and one manual) and one thin wire. (No idea) I have zero power on anything. the breaker is on and I get power to one terminal on the switch at the helm (also brown wires) The other two switches for the mid and aft work fine both in auto and manual and all three switches have the same output. Odd in all 3 instances with the switch in either position do I get power of the brown terminal. So is the power I am reading the power in? With the 2 pole switch 3 blade connector all that is connected is two brown and black ground. So how is this setup? auto power from the Battery directly and bypassed with the switch? without the third wire I don't see this working all from the switch. bottom line is where to start looking for power? My initial thought is a bad ground? Help and thanks

[Midnightsun]

Black is ground, the manual wire (usually solid brown) goes to the manual on/off switch. In other words if you were to hook the brown directly to 12v it would fire up the bilge pump. The auto wire (usually brown with white stripe) goes to a flott switch which when activated sends 12v to the pump. Pretty easy to troubleshoot with a volt meter.

Welcome to CYO.

[azindianrider]

Yes, I have a black/brown wire that is like a romex 2/10. this I assume is back to the battery. then a single brown that assume to the helm. But I get no power on either??? Regardless of the switch position

[Midnightsun]

The helm switch needs to be on for power to get to the pump. Have you tested for 12v at the switch. There must be a fuse or breaker for this circuit, have you checked that?

[azindianrider]

The switch at the helm is auto or manual. 2postion switch. No off position. From what I understand power for the auto is direct from the circuit breaker. I get 12v at the switch.

[km1125]

The auto lead (which goes through the float) should get it's source power from a different breaker than the 'on' switch. Usually the "on" switch at the helm is fed from the main panel AFTER the main battery "1-both-2-off" switch and the float is fed directly from one of the batteries. This should also have a breaker or fuse in the line, and it might be connected on the input side of the "1-both-2-off" switch (if your boat is wired with two batteries and one main switch)

[azindianrider]

Agreed. So we all understand we have basically 2 separate power source. What would cause not to have power to both. I get power to the switch. I think I might have a bad ground since both require the same one

[km1125]

Are you sure it's not a "ground" problem? When you're checking for voltage in the bilge, what are you putting the negative lead of the meter on?

[azindianrider]

On the black wire

[bud37]

Check continuity from a known good ground point to that black wire, it may require a long test lead.......have you found the float switch yet ? It will or should be powered at all times, unless there is a breaker in that circuit that has been tripped or shut off.

Check continuity on all the wiring from switches to the pump itself.