TRUCK NOT CHARGING BATTERY

I have 2010 Toyota Tundra and a 2009 rpod-175.  I've checked fuses on the Tundra and all is well.  I've used a voltmeter to check the 7-pin connector and it reads 12V output.  I check the trailer battery and it reads 12V.  But when I hook up the trailer to the 7-pin, both the battery and the voltmeter in the truck remain at 12V, when I understand both should read 13.8 when charging.  If we're running the fridge on the battery while driving, by the time we get to our destination the battery is down to one light or worse.  What could be causing this?

It sounds like you have checked fuses.. but (and I don't know squat about Toyota's) on our Ford, when we installed the actual electrical part of the towing package, which included the brake controller pigtail and two fuses, 1 of those fuses was for the charging system for the trailer connector, and was NOT installed from the factory.. If I had not had the instructions from the factory package, I might not have ever known about that fuse..

Brin wrote: Have you checked the output of the alternator?  It should also read 13.8 to 14.2.

ibosket wrote: Brin wrote: Have you checked the output of the alternator?  It should also read 13.8 to 14.2.   No -- how do I go about doing that? Curt

The easiest way is to check the battery in the TV. DMM across the +/- and you should have 12. something.. start the truck, and you should have 13.0 + If your truck has under drive pullies, you may need to rev it up to 1500 or so.

Kenn wrote: Ever tried putting it on propane instead? It uses far less battery power that way. It will also charge your battery faster since, you're only using a fraction of what it would use with a 12V option.

I'd rather not drive with the propane on. I think in some places, it's actually illegal to do so (especially when going through tunnels).