Low voltage at the cigaret lighter

[Bill and Nancy]

This is a weird issue, my wife just told me about it just this morning  so I haven't had a chance to diagnose anything yet. Apparently there is low voltage at the cigaret lighter that is over the cook top. I have a 12 volt tire pump with a built in flash light. If you plug it into the 12 volt receptacle above the cook top the flash light is dim and the pump will not run. If you plug it into the 12 volt receptacle above and to the right of the TV it works fine. It appears that the outlet over the cook top is not getting the full 12 volts. When we purchased the pump a few months back we pumped the tires using both of the receptacles and they both worked without any issues. We used the one over the cook top to inflate the tires on the curb side and the one next to the TV to inflate the tires on the street side without a problem. I tried it with the inverter on running off the batteries and with the inverter off and on shore power, nothing changes.

Something weird is going on.

Bill

[Steph and Dud B]

The inverter shouldn't have any effect on the 12v outlets. They run directly off the batteries. Sounds like an issue with the outlet itself, or the wiring connection to it. First, look up inside the 12v socket/outlet. There should be metal around the perimeter of the side wall and a separate piece of metal in the center of the bottom of the socket. Those are your 2 connections to the plug (- on the side and + on the bottom). Is all that metal shiny? Not corroded in any way?

[SeaDawg]

4 hours ago, Steph and Dud B said:

The inverter shouldn't have any effect on the 12v outlets. They run directly off the batteries. Sounds like an issue with the outlet itself, or the wiring connection to it. First, look up inside the 12v socket/outlet. There should be metal around the perimeter of the side wall and a separate piece of metal in the center of the bottom of the socket. Those are your 2 connections to the plug (- on the side and + on the bottom). Is all that metal shiny? Not corroded in any way?

Yup

[Bill and Nancy]

This is still a puzzle. Oliver sent me a new cigarette lighter socket to replace the existing one over the cook top. I replaced it and its not the problem. With a little more investigation this is what discovered. There is 5.4 volts at the socket but if I disconnect the adjacent usb plug the voltage will jump to 12 volts. The cigarette lighter socket under the dinette and the socket above the bed and to the right of the TV bother register 13.5 volts. I have a call into Oliver and am waiting to see what they say. I’m thinking a bad ground someplace or a loose connection. I haven’t had the time to start ripping things apart and I’m waiting to see if someone might have an idea where to begin looking.

bill
 

 

[topgun2]

10 hours ago, Bill and Nancy said:

I have a call into Oliver and am waiting to see what they say. I’m thinking a bad ground someplace or a loose connection.

I think that you are on the correct road with this one.

Did Oliver send you just he 12 volt outlet or a combination 12 volt and USB?

Your comment about disconnecting the adjacent USB is a big clue I think.

God luck!

Bill

[Frank C]

14 hours ago, Bill and Nancy said:

There is 5.4 volts at the socket but if I disconnect the adjacent usb plug the voltage will jump to 12 volts. 

This is definitely a big clue.  5 volts is the nominal charging voltage of a USB port to charge connected devices.   If you are seeing approximately 5 volts at the adjacent cigarette lighter instead of 12 volts, I would check the wiring between the USB socket and the cigarette lighter to make sure they aren’t incorrectly wired.  They may be incorrectly wired in series, or reversed polarity, or the USB charger port may be defective.   They should be wired in parallel to the trailer DC power circuit and ground. 

[Bill and Nancy]

For those of you that are interested I pulled the connections off from the back of the terminals and Isolated  the two sockets compliantly from the trailer wiring. I made up a pig tail and ran it from the cigarette lighter from my truck to power the two sockets. The usb worked fine and the cigarette socket read 13.5 volts. So now I knew it must be somewhere in the trailer wiring. After much investigation I found a loose ground inside the EMS under the back dinette seat. I snugged it up and checked all the other connections and lo and behold I now have 13.5. Volts at the socket. Before opening the EMS I contacted Oliver service and told Hanna what I suspected. She gave me the authorization to open up the EMS to check for a loose wire. She said it was a first but was glad I found it as a bad ground can cause an over heat situation.

Bill

[Steph and Dud B]

Nice work!

[MAX Burner]

@Bill and Nancy:  BRAVO/ZULU, Brother!  Well Done.

[Rivernerd]

13 hours ago, Bill and Nancy said:

After much investigation I found a loose ground inside the EMS under the back dinette seat.

Please forgive my ignorance, but what is the "EMS" under the rear dinette seat?  Are you referring to the 12V fuse block?  Or the main 12V grounding bar?

[Bill and Nancy]

1 hour ago, Rivernerd said:

Please forgive my ignorance, but what is the "EMS" under the rear dinette seat?  Are you referring to the 12V fuse block?  Or the main 12V grounding bar?

Its the EMS stands for Electrical Management System, Its a computer that is located in a black box  about 6 inches square where the shore power comes into. 

Bill 

[Frank C]

16 hours ago, Bill and Nancy said:

For those of you that are interested I pulled the connections off from the back of the terminals and Isolated  the two sockets compliantly from the trailer wiring. I made up a pig tail and ran it from the cigarette lighter from my truck to power the two sockets. The usb worked fine and the cigarette socket read 13.5 volts. So now I knew it must be somewhere in the trailer wiring. After much investigation I found a loose ground inside the EMS under the back dinette seat. I snugged it up and checked all the other connections and lo and behold I now have 13.5. Volts at the socket. Before opening the EMS I contacted Oliver service and told Hanna what I suspected. She gave me the authorization to open up the EMS to check for a loose wire. She said it was a first but was glad I found it as a bad ground can cause an over heat situation.

Bill

Glad your issue seems to be resolved. And good to have caught the loose ground.   But I don’t think the low voltage at the cigarette lighter was related to the EMS ground.  The Progressive Industries EMS is part of the AC shore power input system, separate from the 12 volt DC circuits.  The Progressive Industries EMS feeds into the Progressive Dynamics converter/charge controller to charge the batteries.  All of the 12 volt systems and accessories are connected directly to the battery 12 volt supply bus bar (through the DC fuse panel) and the DC ground bus bar.   You may have unknowingly fixed the issue when you were disconnecting & reconnecting the USB port and cigarette lighter socket.  Maybe a slightly corroded terminal contact, etc. 

[Bill and Nancy]

The funny part is I replaced the socket with a new one and it didn't fix the problem. I am very interested in what might have fixed the issue. I went into the fuse panel where the automotive fuses are and found the red LED next to the #9 fuse was lit. It is labeled usb. Number10 fuse is also labeled usb. The lighter socket under the dinette and the one by the tv both indicated 13.5 volts. My guess is they are on fuse # 10 I did not test them to see if that is the case. So I unplugged Fuse # 9 and did a continuity test and it was good. I put it back in and the light went out and everything worked and I now had 13.5 volts not 5.4 volts at the socket above the stove.  While i had my head under the table I could hear a buzzing coming from  from the EMS. It sounded like a loose connection arcing out intermittently. The bundle of wires going into the EMS were very loose and if I wiggled them I could get the buzzing to go on and off. I opened the EMS and found a loose ground, I snugged it down and the buzzing stopped. My guess is you are right and it was two separate issues. I think the connection on the fuse was either corroded or the fuse was not seated correctly causing the low voltage at the socket. The loose ground in the EMS had nothing to do with anything but would have become an issue down the road if I hadn't found it and snugged it down.