Dimming Lights

by Debbie (St. Louis, MO)

Question: We purchased this 1999 Class A Four Winds Hurricane RV used from a prior owner. It did not come with any manuals and we had some problems last weekend with two things. We had power to everything and then within an hour the lights dimmed and eventually went completely out.

We tried troubleshooting everything we could think of to get them back on but never got them on again. Any help would be appreciated.

Also, there is an on/off switch on the side of the sink cabinet next to the jackknife couch that has no marking identifying what it is for, any help with this would also be appreciated.

Answer: Our best guess is that your house batteries are dead since your lights were on, then dimmed and went out. Your interior lighting uses 12 volts (battery power) to operate.

If you can connect to shore power, your onboard charger should replenish the batteries if the batteries are not too far gone, and if your onboard charger is good. Or if you have an onboard generator start it up and try to recharge the batteries, or you could start the motor home engine and you will get some charge to the house batteries, but it might take a while.

If you were hooked up to power and everything else continued to operate fine (just the lights dimmed), then you charger could also be bad.

Try taking a reading at your house batteries after they have rested without a load for at least 24 hours. Use a volt meter to take a reading of your batteries. If the meter reading is 11.58 volts or better, then your batteries can be recharged. If they read less than 11.58, then you will have to replace them. At under 11.58 volts the batteries become sulfated, and by the time they get down to 10.8 volts (or zero state of charge) the batteries are considered so depleted that recovery is near impossible.

However, the best test of battery life is a load test. This will require you to take your RV or batteries to a service center.

Regarding the switch, we have no suggestions as to what that is for. You might be able to try tracing the wires to see if you can figure it out or uncover a loose connection, but we caution against working on live wires or working with electricity if you do not have the expertise to do so.

Other input welcome.