2800 - Rear bed lighting dead + brown/red 7.5A MPI wires?

[codingparadox]

I noticed tonight, after doing my massive DC rewire, that the only thing that doesn't seem to be working is all of the lighting in the aft/rear bed. The little reading lights aren't powered, the overhead lights aren't powered -- both switches by the bed do nothing (though I don't remember what the second switch does there, to be honest.) Any idea if that connection is fused or wired into house power in some weird way that I accidentally shut off? Tomorrow night I'll go through every fuse in the fusebox under the helm to see if it's one of those that's blown, but I'd be pretty shocked if I somehow blew one fuse to those lights as part of this...

Second question: There are two brown/redstripe wires that were attached to 7.5A fuses that used to be attached one to each battery array (one to house battery +, one to starter battery +), as part of the "MPI" harness. I have no idea what they were related to, but the motor starts and runs happily without them, and plugging them back into house power doesn't change anything about the above question in the lighting. Any idea what the heck these things are?...

[mmwjr]

Should be a fuse but you may need to verify continuity of both supply and return wires is good. Brown wire sounds like bilge pump float switch power.

[shrew]

In the 2800 mid cabin....one switch is for the overhead puck lights. The other switch is for the courtesy light. With wire coloring, black should be the common ground. All other colors are postive (power). Brown (commonly with a red stripe) is a secondary power leg. As Mike mentioned, you usually see that going to a bilge pump. 1-red, 1 brown/red, 1 black. The red and brown with red stripe are positive. One typically goes to the manual switch at the helm. The other to a float switch.

Volt meter the wires at the device.

[codingparadox]

Ah! That'd explain why it was one to each battery -- so that in case of emergency, they'd always work with everything shut off, even with one battery bank totally dead. I'll have to check that those are what they, in fact, are, and re-attach those to the right places, then. Thanks!

[mmwjr]

Originally Posted by codingparadox

Ah! That'd explain why it was one to each battery -- so that in case of emergency, they'd always work with everything shut off, even with one battery bank totally dead. I'll have to check that those are what they, in fact, are, and re-attach those to the right places, then. Thanks!

Actually I think one is for each pump.

[codingparadox]

Yeah sorry, I meant that one was for each pump so that at least one pump would still work to save the boat if one if the battery banks were dead.

[shrew]

Originally Posted by codingparadox

Yeah sorry, I meant that one was for each pump so that at least one pump would still work to save the boat if one if the battery banks were dead.

Are we talking about bilge pumps or cabin lighting? Cabin lighting should be tied to the DC panel, which is tied to the battery switch. I would not expect cabin lighting to be directly wired to batteries. That would mean there is no way to easily isolate the circuit.

[mmwjr]

Originally Posted by shrew

Are we talking about bilge pumps or cabin lighting? Cabin lighting should be tied to the DC panel, which is tied to the battery switch. I would not expect cabin lighting to be directly wired to batteries. That would mean there is no way to easily isolate the circuit.

This thread is talking about both; post 5 & 6 is about the bilge pumps.

[codingparadox]

I dug around in the fuse panel, checked every fuse and tightened every spade connector, and the cabin lights started working again. Magic!... (hooray old boats)

I plugged the bilge pumps one to each battery bank on my ACR panel, but didn't try running them to verify (there's still oil in the bilge right now from before I changed the valve cover gaskets.)

[shrew]

Checking every fuse forced you to unseat and re-seat each fuse. corrosion builds up over time and impedes the connection. Unseating and re-seating the fuse scrapes off the corrosion and makes a clean contact again. We used to have the do this with cards on motherboards back when I used to work on the hardware side of servers. If a network card, video card, etc died, the first thing we do is unseat and re-seat the card. 90% of the time it fixed the issue.

It might be time to replace the fuse bus boxes, fuses and connectors. Not expensive, but awkward. It will take a few hours and a lot of diligence.

[MaxJohns]

Originally Posted by shrew

If a network card, video card, etc died, the first thing we do is unseat and re-seat the card. 90% of the time it fixed the issue.

Thanks, man! I'll be keeping this in mind as well, just in case.