Lights won't come one in my tt with just battery power.

williamsfamilyrvers wrote:
It's the water pump and it is a TT.

it always helps if you post year and make/model of RV you have.
that's why many of us have ours listed in our signature line.

battery disconnect switches are not common on TT's, unless the previous owner installed one.

Look adjacent to the 120 volt circuit breakers in the power distribution panel for a small plate covering the 12 volt DC fuses. Check all fuses with test light. The pump should be working out of this panel so you are getting power to the DC portion of the electrical panel.

This may sound dumb but when you open the slide is the out and in reversed. eg does the slide go out when you push in and vice versa? If so your cables may be reversed. If not, they may have been reversed briefly at one time and the two 40 amp fuses are blown. No worrys if that is the case. Just change them and continue on.

Everytime I hear of these sympthoms I always think to check the installation of the battery terminals cables. It is so easy to get them reversed.

When they get reversed they will blow an in-line fuse between the battery and DC Power Distribution Panel. This will also blow two fuses in the Power Distribution Panel called "REVERSE POLARITY" fuses which are usually off to them self on the panel.

Items that are powered directly from the battery terminals will continue to work - Only those items that come off the Power Distribution Panel will not work with just the battery providing 12VDC.

Simple to check - Just fine the word "NEG" or the stamped symbol "-" on the battery case and physically hand trace the connected battery terminal cable and make sure this is the one that goes to the trailer FRAME GROUND which will be very close to the where the batteries are installed.

Once you get the battery connected properly then find all the blown fuses and replace them.

just my thoughts...
Roy Ken

It's the water pump and it is a TT.

OP stated that he has power to water, if he is talking water pump theen it is in DC power distribution.
OP:
What type of water are you talking? City water or water pump?
What type of rig, MH, TT or 5er?

Not all TTs have one. Mine is near the door, but that's in a Four Winds MH.

tenbear wrote:
Did you forget to turn your battery disconnect switch on?

Didn't know there was one, haven't had an rv in over 10 yrs. Where would it be located?

Did you forget to turn your battery disconnect switch on?

Sounds like the problem I had about a month ago. Check this link.

turned out to be circuit breaker