Fridge and freezer cycling on and off

[Fearnow]

How do I trace the wires from the fridge and freezer? There is a 1 volt drop, causing them to cycle on and off.

[Scott Berg]

When you say a one volt drop are you saying that when the unit is turned off you see a volt less at the units terminals than you do at the battery post?

Model of the unit
Voltages measured
A traditional voltage drop test would be between the unit and the circuit breaker; should be 0 volts on the wire
As for tracing it that depends on the boat, where the panel is, etc...
We need more info. FYI if you have the boat on a charger (13.5v or so) then the 12.5 at the fridge/freezer should be fine so you might have a different problem altogether.
If you are measuring voltage UNDER LOAD you may indeed see a drop (ohms law and all that)

[Fearnow]

With no load, voltage at the freezer is 11.9 volts and 13.1 at the battery. This is without the charger on. There is a fuze box ,but nothing is marked. All the connections are tight and look good. Fridge and freezer stay on and run fine when hooked up to shore power, or when running engines. Once house batteries go below 12.5 volts, both fridge and freeze begin to thaw. Will check on the brand names.

[autumnbreeze27]

What gauge is the wire and how long is the run? Could be you need larger wire or a shorter run if you don't spot any signs of corrosion on the ends or in any splices or junctions


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[skipmac]

99.9% of the time if you have a problem with voltage drop in a wire that was previously OK then the problem will be a loose or corroded connection on one of the ends. In this case on the switch panel or where the wire connects to the refrigerator/freezer. First step is cleaning and tightening the connections on both ends of the wire.

However no guarantee that the wire was not undersized from the factory which makes the system even more sensitive to a small volage drop caused by a bad connection. I would check the wire size and estimate the distance from the switch panel to the fridge. You can check wire size you need with the gauge calculator on this page. Voltage Drop Calculator Genuinedealz.com

If wire size is correct and checking the end connections doesn't solve the problem you may have to trace the wire. Generally there's no way but to start at one end and follow it through the boat. The only other option is to buy a wire signal tracer. It's a little kit with one gadget that puts an electronic signal into the wire and another gadget you carry around and hold next to different wires to follow the signal. Not very expensive and can be handy to have around.

[Cadence]

A 1.2V no load drop. You must have about a disconnected wire. Check that again the high impedance of the meter won't cause that drop. Don't just look at the terminal ends on the wirer. Look at the crimps and wire that could be corroded back considerably under the insulation. Salt air is great. Cutting the wire back an inch under the insulation wouldn't be unreasonable. Sounded like you didn't find the all of the connects, fuse or circuit breaker should be in the line with connections in and out with possible corrosion. A breaker can develop resistance.
For what it may or may not be worth. Good luck this it. The last boat I had, had all undersize wire and corrosion well back past the crimps on the wire. Seal all new crimps back the wire insulation sleeve.

[w1651]

Originally Posted by Fearnow

How do I trace the wires from the fridge and freezer? There is a 1 volt drop, causing them to cycle on and off.

Start with a fully charged battery.
then follow the wirse to the fuse or breaker and check for a drop.
then go across the fuse and breaker checking for a drop.
Then from the breaker to the fridge checking for a drop.
you may find that the problem is at the battery or breaker itself. if so no more wire problems and the fridge works fine after fixing the problem.

[Fearnow]

Thanks for all the replies. I don't know the gauge of the wire, but it appears to be approx. 3/16" and heavy enough for the 17' run. The fuse box is not marked and that is the challenge, finding the fridge and freezer wires. Going to start checking the connections,as there are a few that were factory sealed, but may be the problem. The fridge and freeze draw about 5A each when running. And they run a lot, as the seals on both are in bad shape. Lousy design, as neither have drains and have been dumping on the floor for years. Hence, the floor is rotten.

[Paperbird]

We had a similar situation and opted simply to replace the wire with a new, heavier gauge wire. I figured tracing it would only confirm that I needed to replace it. And it took a lot less time to run the new wire.

YYMV

[skipmac]

Originally Posted by Fearnow

Thanks for all the replies. I don't know the gauge of the wire, but it appears to be approx. 3/16" and heavy enough for the 17' run. The fuse box is not marked and that is the challenge, finding the fridge and freezer wires. Going to start checking the connections,as there are a few that were factory sealed, but may be the problem. The fridge and freeze draw about 5A each when running. And they run a lot, as the seals on both are in bad shape. Lousy design, as neither have drains and have been dumping on the floor for years. Hence, the floor is rotten.

Is the 3/16 the outside diameter of the wire IE including the insulation or the diameter of the copper inside? If the overall diameter, unless the insulation is really thick this is at least 8 or 10 gauge and probably adequate.

You are looking at the fuse box. Is that a completely separate unit from the switch panel? If yes, do you have a volt meter? The turn off everything on the switch panel and have someone turn the fridge on and off while you check the voltage at the fuse panel.

The rotten floor is a bummer. If no drains in the boxes how does the water get onto the floor? Is it a front opening door so just leaks out the bottom?

[Fearnow]

The copper wire is 3/16" and there is a seperate fuse box, but most of the info stickers are missing. There are about 6 heavy gauge wires and almost certain that two of them go to the fridge and freezer. I assume there must be one hot wire coming from the battery to feed the panel, and that the wires from the fridge and freezer don't go directly to the battery?

The boat was in charter and every time they defrosted, the water was allowed to just drain on the floor. Obviously, I don't allow that to happen anymore, but it's getting old, moping it out every time I defrost.

[skipmac]

Originally Posted by Fearnow

The copper wire is 3/16" and there is a seperate fuse box, but most of the info stickers are missing. There are about 6 heavy gauge wires and almost certain that two of them go to the fridge and freezer. I assume there must be one hot wire coming from the battery to feed the panel, and that the wires from the fridge and freezer don't go directly to the battery?

The boat was in charter and every time they defrosted, the water was allowed to just drain on the floor. Obviously, I don't allow that to happen anymore, but it's getting old, moping it out every time I defrost.

Very unlikely the power wires for the fridge and freezer go directly to the battery unless it was wired by an idiot a technician with poor skills.

Sorry I am unclear about the setup. Does the boat have two separate panels? One that is a fuse panel and another that has the on/off switches? Does the power go from a switch panel to a different panel with fuses and then to the fridge/freezer or is there just one panel?

Is there no power light on the fridge or thermostat? Can you hear it running? Turn off the switches one at a time until the lights go out or the fridge stops running. NOTE: If you do turn off the running fridge wait a few minutes for the pressure to equalize before turning back on.