Unable to get power from my truck battery when connected to the trailier!

[Ribbler]

My camper battery/electrical system is unable to get power from my trucks batteries. My camper battery is able to charge on 120 volts, although the battery is unable to hold a long charge. In the past, I was always able to boost the battery power and use the lights/water pump by simply plugging my truck in. All the lights/ turn signals and brakes work while driving.

Basically, I'm unable to access my truck batteries while plugged into my truck.

So is it my camper battery, a poor connection from my truck, or is it the converter in the camper?

[Bill M.]

Most likely a bad battery. The truck does not provide much of a charge even when the battery is good. You can check with a meter to see if you are getting power from the truck. Could be a blown fuse due to a weak battery.

[dwightdi]

The converter in the camper is not in use when the truck is plugged in but 120VAC is not. Because the camper battery runs down quickly and does not hold a charge for a couple weeks means the battery is bad and needs to be replaced. You also may have a poor connection where the camper plugs into the truck. Clean it and check the voltage in the trailer when the trailer battery is disconnected and trailer is not plugged in to AC.

[Ag&Au]

Originally Posted by Ribbler

My camper battery/electrical system is unable to get power from my trucks batteries. My camper battery is able to charge on 120 volts, although the battery is unable to hold a long charge. In the past, I was always able to boost the battery power and use the lights/water pump by simply plugging my truck in. All the lights/ turn signals and brakes work while driving.

Basically, I'm unable to access my truck batteries while plugged into my truck.

So is it my camper battery, a poor connection from my truck, or is it the converter in the camper?

Sounds like your camper batteries. Disconnect your camper batteries at the battery posts and then, with no shore power, Plug into your truck. If you can now get light from your fixtures, your camper batteries are bad. If you still can get no light, then you have a bad 12V+ connection to the truck. This is assuming that your truck batteries are good.

Ken

[Ribbler]

Thanks, Looks like the camper battery is no good. I will give battery another chance, that's until I get a new one. If the truck connection is good, then why am I not getting the power to the camper lights etc.? Should the truck batteries by-pass the failing camper battery, or do I just have to disconnect the camper battery for this to work? Or, of course, get another deep cycle battery for the camper? Thanks.

[jdalrymple]

All the connections are in parallel. This means there is no way for the truck batteries to "bypass" the bad trailer battery.

The amount of current supplied by the truck is small, simply because of the distance from where the wire leading to the trailer is connected to the power of the truck.

Remember, DC current does not like to travel far. Think of water traveling a long distance in a garden hose. There is much less pressure at the end of the hose than at the faucet, right?

The bad battery in the trailer sucks up what is left, and leaves none to run your trailer. To get through until you can buy a trailer battery, you would be better off to just disconnect the bad trailer battery and use only the truck. Keep in mind your truck battery will be running down.....

Good Luck.

JD

[Ribbler]

Thanks for the info Jeff

[jdalrymple]

You are welcome,

And, Welcome to the forums!

JD

[Splitrock]

A 7-way tester will show if all is well coming from the tow vehicle.



I paid about $10 for mine two years ago.

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