Interior lights not working

[SteveJordan]

I have a 1998 Monaco Signature 450 hp Cummins. The interior lights are working but not dependable. It acts like the salesman switch is not working.
I jumped the solonoid with the purple wire just below the big one in the engine compartment.
I left the vehicle for an hour and the lights would not come on. I started the coach and on came the lights. I find this odd.
When I jumped the solonoid I did nothing with the purple and black wires that go to the solonoid. Is that the problem? I don't think it is.
Does any one have an thoughts. I realize this has been discussed many times before but I am stumped. Thanks for any thoughts... Steve

[Rex]

Steve, to bypass the salesman solenoid, you should tie the large cables on each side together. The purple wire comes from the switch and it energises the solenoid. Disconnect the purple wire and tape it up or just leave it on the solenoid.

You may be lucky and one of the large RED battery cables may reach from one side to the other. If so connect them both to the same terminal and you have bypassed the solenoid. That should restore you lights. If they will not both reach the same terminal, then connect them with a bolt and tape it up real good.

[SteveJordan]

Rex thanks for your thoughts, I jumped the solonoid just as you had suggested and left the purple and black wire alone. The lights would not come on about an hour later. The lights came on when I started the coach. I still have a problem some where. It is odd the lights come on when I start the coach. Thanks Steve

[Gordon66]

Sounds like the coach batteries are dead and your lights are working off the engine alternator.

[Mike Canter]

Have you checked your house batteries to make sure they are good?

[SteveJordan]

Thanks for your thoughts I agree the lights must be starting off the altenator, but once the lights come on I have shut the motor off and the lights stay on. The lights seem bright and stay on for at least 20 minutes and then I left shutting the lights off only to return 3 hours later to find the lights not working. I will check the house batteries but they were ok last week,voltage was good when I checked them. I cleaned up all the terminal connections, Is there another solonoid that controls the house lights?
The house batteries are getting old (5yr so perhaps they are getting marginal) I had a trickle charge on the batteries. I will check this out letting the batteries sit after taking the charger off, then seeing what the voltage is.
Again thanks for your thoughts Steve

[Mike Canter]

Lets stop and think. If the lights work after the engine is shutoff then all the solenoids, relays and wires are good. My guess is the house batteries are bad and only holding a surface charge off the alternator which depletes fast. When you check the battery voltage then check right away after you shutdown the motor then every hour until the lights die.