Truck not charging batteries

[searching for nowhere]

On my last trip the solar wasn't charging the batteries (now fixed) and I then noticed that the truck wasn't charging the batteries when I was driving. I saw some corrosion at the 12v location on the trailer plug but I wasn't brave enough to work on the plug while on the trip. Now home I installed a new trailer plug thinking the 12v connection in the plug was bad. I connected the new plug into my truck, turned on the truck and checked the battery monitor (Bogart Engineering). I saw no change in the amp reading on the battery monitor. The turn signals and trailer lights worked. The batteries were fully charged and the monitor read positive .2 amps due to the solar panels charging.

Am I correct in thinking I should see a change in the amp reading on the battery monitor when I plug it into the truck (2020 Chevy Silverado)? I've read on the forum that trucks do a poor job charging the batteries, but shouldn't I see some charging?

If this is true, my next step will have a mechanic test the truck 7 pin connector. I already have a service appointment for the end of the month for other things. I'll just add it to the list.

Thanks for any ideas.

 

[Vic Harder]

On my last trip the solar wasn't charging the batteries (now fixed) and I then noticed that the truck wasn't charging the batteries when I was driving. I saw some corrosion at the 12v location on the trailer plug but I wasn't brave enough to work on the plug while on the trip. Now home I installed a new trailer plug thinking the 12v connection in the plug was bad. I connected the new plug into my truck, turned on the truck and checked the battery monitor (Bogart Engineering). I saw no change in the amp reading on the battery monitor. The turn signals and trailer lights worked. The batteries were fully charged and the monitor read positive .2 amps due to the solar panels charging.

Am I correct in thinking I should see a change in the amp reading on the battery monitor when I plug it into the truck (2020 Chevy Silverado)? I've read on the forum that trucks do a poor job charging the batteries, but shouldn't I see some charging?

If this is true, my next step will have a mechanic test the truck 7 pin connector. I already have a service appointment for the end of the month for other things. I'll just add it to the list.

Thanks for any ideas.

If the batteries are fully charged, you should not see any current flowing into them at all. To test your fix, you will need to drain the batteries a bit first.

 

[searching for nowhere]

Thanks much. I'll give that a try tomorrow.

 

[searching for nowhere]

I let the batteries get down to 93% charged, plugged in the running truck and... nothing happened. No change in the amp reading. I'll have a mechanic test the 7 pin connector on the truck. I did try testing it with a volt meter but I'm not sure if I got the volt meter touching the connector correctly. Maybe the problem is a fuse in the truck.

But this isn't a crisis. I'm going to sell the trailer and just want to tell potential buyers if the connection doesn't work. I don't want to hide a known problem.

 

[Bigfoot Dave]

There should be a fuse or a circuit breaker at or near the trailer battery that could be tripped/blown.
On my ford the 12V line is not powered unless the engine is running.
There will be a fuse for the trailer 12V line in the truck fuse box too.
Good luck, Bigfoot Dave

 

[searching for nowhere]

Thanks for your thoughts, Bigfoot. I checked the trailer circuit breaker near the battery. It is good. I've had the truck engine running when checking. Due to my solar problem, I've visually checked all the trailer wiring and connections except for where the wires enter the trailer and split. They must have built the trailer after installing the junction box, it is darn hard (almost impossible) to get to. Yup, could be a fuse in the truck put I don't know where the fuses are.

 

[Vic Harder]

Older units had a small (1.5" long) metal breaker, usually mounted on the firewall or close to it. Something like this
RKURCK 12V 30A Circuit Breaker Automatic Reset for Automotive RV Marine Boat with Protective Red Boot Cover : Amazon.ca: Automotive

 

[PaulT]

There should be another auto resetting 30 amp circuit breaker like that under the hood before the ACR in the camper to protect the camper to truck circuit from the camper end.

Paul

 

[searching for nowhere]

Vic: Thanks for pointing out the metal breaker. I have one and had ignored it since I didn't know what it was. Not good. Now knowing what it is, I placed a wire jumping across it and... no change to the amps in the battery monitor.

I'll go back to doing what I know - cleaning and emptying the trailer. If anyone wants a 17.5 Bigfoot I plan to have it on market in February. I'm changing to a camper van.

 

[Vic Harder]

As Paul points out, there is another breaker like that in the camper too...