Control panel/univolt

[4thQTR]

Just purchased 1976 Sovereign 31 rear bath. Going all in! I am currently just in the “discovery” phase and I am having difficulties figuring out the 12 v system. Control panel is inop. No lights no gauges etc. No interior lights switch’s etc. Multimeter shows 12 v throughout panel. Checked all fuses. Plug in 120ac,again no lights switch’s etc but 120 plugs work fine. Univolt humming with 120 plug in. Could all my appliances and fixtures be toast?
I intend to replace all appliances but have only removed the oven at this point. (Capped the wire leads) What am I missing?
I hope you experts will be patient with this rookie. Your info has already been so helpful. Please feel free to let me know if I am making errors. I really want to get this right the first time. Thanks

[TG Twinkie]

Sounds like you may have lost the common/ground connection for the 12 volt side.
Do you have a battery in the coach?
If you have the original converter it is time to upgrade.
Connect a portable battery charger to the battery and see what happens.

[4thQTR]

Thank you for the tip. Yes I purchased a brand new deep cycle for the coach. I will upgrade for sure. Is there a way to test the control panel bypassing the univolt? I am just trying to determine what is and is not operable at this point. I am going ground up so I don't know if I should upgrade converter now or wait. Your input would be appreciated.

[TG Twinkie]

If your battery is charged. There is no need for the Univolt to test things. As long as it is connected correctly.
Do you have 12+ volts on the buss bars of the fuse panel?
Can you post pics of the converter, fuse panel etc?

[4thQTR]

Yes I have 12v at all fuses including the CP. I will post pics tomorrow. Thanks for helping. If you have any other thoughts or ideas let me know.

[uncle_bob]

Hi

If you still have the stock converter from 1976 in RV then yes, you will need to replace it. Replacing it sooner vs later - that's up to you. If you can get things done without a 12V charge system, work on that stuff. I would not want to use the stock unit for very long.

Bob

[featherbedder]

There are 2 50amp fuzes for your yr. one is in ground side of fuze panel other hot side. Sometimes fuze looks good but bad. I have had same issue found in ground side of system. If you have cheap continuity checker check all glass fuzes, some times looks good as stated. IMO TG Twinkie has rite idea about ground prob. The ground fuze is large round and is at bottom of fuze panel mounted horizontal that is one I would check. If bad pm me I will send you a couple as I have a lot.

[TG Twinkie]

Fuses can cook. In other words they lose the ability to carry any significant load.
The metal element can become detached from the end cap. Leaving a carbon trail which would give a positive reading on a VOM.
Making you think the fuse is good.
The fuses must be tight in the holders and not show signs of corrosion.
Look for a fuse which may be mounted separately in it's own (single) fuse holder. It would probably be mounted on the skin. The fuse on the negative side would be inline with the negative battery wire.

[4thQTR]

I decided to continue demolition being I did have 120ac. Removed furnace, removed fuse box from mount and low and behold the 12v kicked on!!! I have tightened all connections but still I have a loose connection somewhere because it will go in and out. At least I know what works! Thanks for your expertise and responses. One last thing, what converter would you recommend?