Battery Drain Help Please

[SW_Explorer]

I'm looking for some electrical advice please. I have a 2005 F350 Diesel and a 2002 AF 1080 truck camper. I keep the camper plugged in to shore power when not in use. Last night while getting ready to head out I fount the truck batteries completely dead. Nothing was on in the truck as far as lights or 12v accessories. The batteries are only 3 months old, as this happened the last time we tried to go out so I replaced them thinking they were due.

Prior to this summer we have never had an issue.

Any thoughts on what could be draining the truck batteries? The camper shouldn't through the umbilible, right?

For what it's worth the camper batteries were also replaced about a month ago, too.

I'm trying to figure out if I should take it to the mechanic or RV repair shop

Thanks in advance for the help as always.

[joerg68]

... and then do the same measurement with the camper disconnected. That way you can tell if the camper can be the source.

Once you have this measuring thing sorted out, you can start pulling individual fuses until the draw goes away. That way you can usually further isolate the culprit.

How long had the truck been sitting? Why do you believe the camper causes this? Was the camper battery also dead, or fully charged as would be expected?
Were all lights out on the truck? All doors properly closed? The door switches go bad pretty frequently.
One possible issue can be the on board computer not "going to sleep", because it senses "something" is not properly turned off. With the resulting draw, it can drain a battery within a week or two, even when you think everything is turned off.

[Sjm9911]

Your plugging the truck into the camper? Not all TV have a shut off so the camper could have drained the batteries. I would charge everything up and disconnect the cord and see what happens. Not really sure how the truck campers work.

[sbryan]

Not sure about the 2005 but my 2013 F350 diesel has a battery disconnect built in. There is a parasitic drain on the truck battery from things like clocks and other electronics but that shouldn't be an issue in 3 months time. I assume you have two batteries since it is a diesel. I keep my truck on a battery tender because it is often months between trips. Disconnect the battery terminal and measure the current draw with a meter. That will give you some idea of how large a drain there is. That is where I would start my trouble shooting. If there any significant drain something is amiss somewhere.