12V Power Issue

Jon S · 06-29-2022, 01:09 PM

I have a NEW Keystone Cougar 5th wheel. Having some 12v power issues. I had my unit in for service at dealer and when it came back after connecting to shore power I realized that my Norcold refrigerator wasn’t working. I thought that was my only problem. In the process of troubleshooting this I disconnected from shore power and now I realize that I have no 12v power although my battery is registering 12.99 volts on a meter. I have verified voltage to the battery disconnect when cover was off but unsure where to go from here. Hope someone can help As we are supposed to leave on a trip tomorrow.

wiredgeorge · 06-29-2022, 01:25 PM

Battery is connected to your converter. Most modern campers have a battery shut off switch. Sounds like you have an inverter. This gizmo may have some sort of switch. If they were working on it, I would look for the battery shut off switch and then the inverter. Put together a signature by clicking on the UserCP at the top/left of each page and then saving he signature. Year, make and model of camper and same for your tow vehicle. This will allow for answers with more context.

Jon S · 06-29-2022, 07:05 PM

Thanks. I will check for inverter in morning.

Jon S · 06-30-2022, 04:39 AM

I do have a battery shutoff switch and it is on. My unit is prepped for an inverter but does not have one. If my battery is good(was replaced at dealer last week and is holding a charge above 12 V) why would nothing in the camper work off of 12 V? My biggest concern is my refrigerator does not come on at all.

**chuckster57** · 06-30-2022, 04:48 AM

If you have a Multimeter, set it to VDC and verify 12V on both sides of the cut off switch. If you have 12V on both sides then test at the 12V side of the power distribution panel. The reverse polarity fuses may be blown, if the tech hooked the battery up backwards for even split second those fuses are designed to blow.

They are either off to the left of all the fuses, most likely 30A or on the back side of the converter. I’m thinking the dealership tech hooked up the battery wrong.

**JRTJH** · 06-30-2022, 05:02 AM

The cut-off switch is a likely source of your problem. If the checks are good and it's not that switch, let's examine the issue:

OK, looking at your "history of events", you say the trailer was working, went to the dealer, he replaced the battery and now the refrigerator and some other 12 volt items no longer work....

Since the dealer disconnected/reconnected the battery, there's a chance that they connected the battery backwards. Many, did I mention way too many, converter reverse polarity fuses have been blown from exactly that event.

Ask yourself, why would WFCO even install a circuit like that on every converter? The answer: Way too many people connect their battery backwards... It's far more common than you might think, even "among the PROs at the dealership"....

Find your converter/charger and check those fuses. If they're good, then go to the battery compartment and find the "automatic resetting circuit breakers". Check them for "input AND output power". Those "little plastic cans" can and very often do, corrode inside, rendering them inoperable.

So, if you locate your converter/charger and check the reverse polarity fuses, I think you might find the problem. If they're good, likely one of those DC mini-breakers may be the issue.

If all that is good, then some further troubleshooting is in order and the forum is ready to offer the advice on what's next.

wiredgeorge · 06-30-2022, 05:14 AM

On a new Cougar, someone might tell the OP where the WFCO reverse polarity fuses are located and what they look like. I personally have no idea as I don't have a WFCO power center.

**chuckster57** · 06-30-2022, 06:18 AM

Quote:

Originally Posted by wiredgeorge

On a new Cougar, someone might tell the OP where the WFCO reverse polarity fuses are located and what they look like. I personally have no idea as I don't have a WFCO power center.

I believe I told him. I bet your power distribution panel is WFCO.

travelin texans · 06-30-2022, 09:08 AM

I'd start by checking the battery cables, are they connected correctly? Typically white, sometimes red, is positive & black is negative connected parallel correctly, then check that the ground to the frame is clean & tight, then they reverse polarity fuses & work from there.

wiredgeorge · 06-30-2022, 09:48 AM

Quote:

Originally Posted by chuckster57

I believe I told him. I bet your power distribution panel is WFCO.

I honestly don't think it is. It is a 2002 and when I looked it up to buy a new fan thermostat gizmo, found the company was not in business anymore or may have been selling stuff under a different name. Having a touch of resentment for a failing memory, I opened the old Cougar and found the power center to be a Parallax/Magnetek 6300 Q Series (I think Parallax became Magnetek sometime after manufacturing my power center).

**chuckster57** · 06-30-2022, 11:23 AM

Looks like I owe you lunch

Haven’t seen one of those in a long time.

pdaniel · 07-07-2022, 09:29 AM

I bought a 2017 Cougar, new, a few years ago and the power supply failed in a couple of days.
The dealer kept replacing the batteries but further investigation revealed the power supply output was 5.4 VDC.
To check that output the batteries need to be disconnected from the supply using the switch or disconnecting leads from the battery.

**JRTJH** · 07-07-2022, 09:52 AM

Quote:

Originally Posted by pdaniel

I bought a 2017 Cougar, new, a few years ago and the power supply failed in a couple of days.
The dealer kept replacing the batteries but further investigation revealed the power supply output was 5.4 VDC.
To check that output the batteries need to be disconnected from the supply using the switch or disconnecting leads from the battery.

This is from the WFCO Owner's Manual:
"Before checking the converter output voltage, it is necessary to
disconnect the battery cables at the battery . Make sure
the converter is plugged into AC source (105-132 Volts). Check the
converter output voltage at the battery with a voltmeter. Place the
probes on the disconnected battery cables; place the Positive (red) meter
probe on the + positive red battery wire and place the Negative (black)
meter probe on the -Negative black wire on the battery cable. Be sure you
have good connections at the cables. If the voltage reads 13.6 Vdc (+/-.2)
with no load, the converter is functioning properly."

You may also like: