Still no House Power

[Alumi-Naught]

I am still on the hunt for this pesky problem. When I check for voltage at the battery I get 12.6/13.8 depending if I am on battery or shore/generator power. When I test at the individual circuit fuses, using the battery negetive fuse as the neg reference I get a neg voltage at the individual ckt fuse. I would think the output should be a positive 12vdc. This would explain my lack of house power. Has anyone experienced this, any thoughts on the cause

[ralley]

Originally Posted by Alumi-Naught

I am still on the hunt for this pesky problem. When I check for voltage at the battery I get 12.6/13.8 depending if I am on battery or shore/generator power. When I test at the individual circuit fuses, using the battery negetive fuse as the neg reference I get a neg voltage at the individual ckt fuse. I would think the output should be a positive 12vdc. This would explain my lack of house power. Has anyone experienced this, any thoughts on the cause

Check the components between your batteries and the fuse box. The first thing to check should be the solenoid mounted on the back of the battery box, followed by each piece of cable. The problem has got to be there somewhere. Also check the condition of each piece of cable for breaks in the insulation which would cause this problem.

[RoadKingMoe]

Originally Posted by Alumi-Naught

When I test at the individual circuit fuses, using the battery negetive fuse as the neg reference I get a neg voltage at the individual ckt fuse.

Only 4 things should cause a full 12VDC negative voltage at those points:
1) The meter is reading backwards (i.e. the wires in it are swapped)
2) You have the meter leads backwards
3) The positive and negative battery cables are connected to the wrong points on the fuse panel.
4) It's unlikely because of different battery terminal sizes, but battery cables on the wrong battery terminals could cause this

Originally Posted by Alumi-Naught

I would think the output should be a positive 12vdc.

It should.

Originally Posted by Alumi-Naught

This would explain my lack of house power. Has anyone experienced this, any thoughts on the cause

Reversed power polarity doesn't explain a loss of house power. It would not stop resistive devices like lights from working. DC motors should run, but backwards. Electronic devices without a protection diode would probably burn up. With one, they may or may not blow a fuse, depending on whether the diode is series or shunt.

[boatdoc]

Originally Posted by Alumi-Naught

I am still on the hunt for this pesky problem. When I check for voltage at the battery I get 12.6/13.8 depending if I am on battery or shore/generator power. When I test at the individual circuit fuses, using the battery negative fuse as the neg reference I get a neg voltage at the individual ckt fuse. I would think the output should be a positive 12vdc. This would explain my lack of house power. Has anyone experienced this, any thoughts on the cause

Hi alumi-naught; How can you have a negative voltage in DC current? You may have a reversed polarity but not negative voltage. Voltage is a positive pressure, not negative. If your Voltmeter reads Voltage, then the polarity is correct. Available amperage in those wires can be sufficient just enough for the Voltmeter to read Voltage. This however does not mean that you have sufficient available amperage to run your circuits.

In some cases there is a 50 amp fuse in the system on the negative side to double protect your 12 Volt system from shorts coming from shorted or reversed polarity on your 110 UniVolt circuit,through common ground. If this fuse is blown you can only pick up the negative connection through a turned on circuit such as light bulb which is insufficient to provide enough amperage to your panel. Load test the 12 Volt input to your panel, you may have a loose or weak connection there. You can test for integrity of the circuit with a Amp meter hooked in line of a positive lead while connected to battery and applying a known amperage draw load to the end of that circuit. Plug in something of known amperage draw such as 12 Volt coffee pot. If you observe same reading on amp meter as the specified draw at the end of the circuit the wire is good for the amount of that amperage.
Please bear in mind that a bad negative connection produces same results as bad positive connection which amounts to a incomplete circuit. Voltage is the level of pressure, Amperage is Volume. Volume [amperage] is needed to make things work. Thanks and good luck. Need further help PM me. " Boatdoc"

[Chaplain Kent]

locate your 12 volt fuse box, the glass fuses, find the largest fuse there, it'll probably be on the top and check to see of this fuse is blown. Replace it and you will have have power. Did you happen to start your gen set with the shore power connected? That is how I blew this fuse.

[Alumi-Naught]

Found it Thanks to Boatdoc you got me thinking. Turns out it was a high resistance connection at the load side of the positive 50 amp fuse holder where it connects to the positive buss bar.

I used the spare 50 amp fuse located right above the bad one as a temp measure until I can locate a new fuse panel (some of the other fuse holders are a little suspect). Thanks for all your suggestions.


Mark

[str8strm]

Yea