My Power does not turn on fully.

Often there is a time delay programmed into energy management systems.

Are your batteries charged?

There are two power systems in an RV (sometimes 3 or 4 but we will work with two just now)
One is the 12 volt system This consists of the LIGHTS that are delayed. The Battery and the Converter... on a motor home there is a tie in with the chassis 12 volt system under charging conditions or when you press an "Emergency Start" or "Boost" button.. We will ignore that system as it does not apply here.

The other system(s) is the 120 volt system.. That is what RUNS the A/C. the Fridge when on A/C or if A/C only. the Electric water heater. and of course powers the converter to charge the 12 volt system

The additional system here is an inverter that eats 12 volt and spits out 120 volt which you may or may not have.. These systems I'll not talk about farther as they too are not your problem Incluced here for copletness with one exception that's the converter.

SOME converters work better with a battery attached

As someone said there may be a Time Delay. normally not however for the lights and normally NOT on the 12 volt side of life.

More likely that switch you turn off ... Well that's likely either the battery disconnect toggle or it may say something like USE/Store (a 3 position spring return to enter rocker)

Some RV's are wire (most I suspect) like this

Battery (fuse or breaker optional) Switch Everything else INCLUDING the converter...
Also Battery--Some stuff that needs to be on all the time like the explosive gas (Propane) Detector.

The battery can run down to the point where the converter (if small) takes a bit to charge it up after you turn on the switch.

What make and model converter do you have? Most modern ones (This century) you can leave the switch on full time.. Some (mostly last century) not.

The salesman switch (that is what you are describing right?) operates a large solenoid that disconnects much of the DC which should immideately come back on when you press the switch. Check the solenoid as they become pitted from switching DC loads.

Battery charged is an interesting thought as the charger should not be switched but maybe it's been changed. And have the batteries load tested as a possible issue.

And a 26 year old RV has had repairs and likey modifications etc. Posting make/model info can be helpful. Also a good idea to take a lot of pictures of everything.

The salesman solenoid is a latched solenoid that draws NO power except a brief instant when it changes states.. This is not and different than the battery boost swithch which provides a temporary connection between the two battery banks and is intended for starting with a weak chassis battery.

CA Traveler wrote:
The salesman switch (that is what you are describing right?) operates a large solenoid that disconnects much of the DC which should immideately come back on when you press the switch. Check the solenoid as they become pitted from switching DC loads.

Battery charged is an interesting thought as the charger should not be switched but maybe it's been changed. And have the batteries load tested as a possible issue.

I mentioned the battery charge because I had a previous Class A with the same symptoms as the OP. Despite being plugged in the batts were toast and the storage switch solenoid wouldn't click over. New batts solved the problem.

Bad batteries can/do cause so meny different and often very unusual symptoms. Yet few RVs are unaware of this and overlook one of the most simple and basic tests to eliminate that possible issue. So yes excellent input.

And 1 day old batteries can fail, sure not as likely but...

PaulRVer...Any update? Is it working OK now?