Breakaway Battery Charging

[Scrounger]

Update, spoke to a GM engineer, nice to have media connections, and the hot lead to the charge/aux circuit is hot with the key on or off if the fuse is installed under the hood for it in slot 1. Its labeled in my truck pretty well.

Looks like I have to install and isolator myself.

 

[Egon]

On my system the when ever the trailer plug is plugged in the green light on the controller is on. If this light is on I just assume the break away battery is on a live line.

 

[medicshawn]

My 2004 Dodge is hot all the time as indicated by a charging led on my trailer battery.

 

[Diamondpilot]

No idea where the LED would be. On the truck or the trailer. Nothing on the trailer that I can see. This is a mystery to me. Maybe I should call a GM service line if I can find one.

High end brake-away battery boxes have a LED on them to show you the charger is working. Most we see in my neck of the woods do not have the LED. Only way you can tell its working is once a year put a volt meter on it and look at the brake-away voltage, something around 12V. Now start the truck and if things are working right you will see something around 14V.

Chris

 

[Diamondpilot]

I still think something is not right with your guys trucks that have 12V at the plug with the truck off. I can tell you that if that were the case on all trucks I would be jump starting about 200 vehicles every weekend at the marina and campground with trailers left hooked up to them.

Chris

 

[Egon]

I still think something is not right with your guys trucks that have 12V at the plug with the truck off

I'm pretty sure that with my 96 Dodge the breakaway battery has power to it even with the key turned off as the controller always shows a green light. Never had any problems with low batteries as the breakaway battery is just the third battery in the system. There is no draw on the breakaway battery as the trailer brakes are not activated.

The camper plug is on a solenoid the is activated by the key being turned on.

 

[Diamondpilot]

I'm pretty sure that with my 96 Dodge the breakaway battery has power to it even with the key turned off as the controller always shows a green light. Never had any problems with low batteries as the breakaway battery is just the third battery in the system. There is no draw on the breakaway battery as the trailer brakes are not activated.

The camper plug is on a solenoid the is activated by the key being turned on.

I think you guys are talking about 2 separate things here. Your controller is wired hot all the time. Its that way so that if for some reason you lose everything you have the ability to activate the trailer brakes manually.

There is a wire that also runs to the trailers on board battery to keep it charged. It is totally separate from the the brake's circuit and its only job is to charge. It is a CHARGE CIRCUIT so it SHOULD only be hot when the vehicle is charging, ie running. Now the circuit is not smart enough to tell if the truck is running or not, all it knows is the keys position.

Chris

 

[Egon]

There is a wire that also runs to the trailers on board battery to keep it charged. It is totally separate from the the brake's circuit and its only job is to charge. It is a CHARGE CIRCUIT so it SHOULD only be hot when the vehicle is charging, ie running. Now the circuit is not smart enough to tell if the truck is running or not, all it knows is the keys position.

Darned if I know??

I should check it out some day.

 

[George2615]

As I stated before and Matthew backed me up that on GM products the trailer plug charge lead is a separate circuit connected to the under hood fuse box. If the fuse is installed the charge lead on the trailer plug is hot whether the key is on or off. There are no relays or anything else in line to turn it off. If someone who owns a GM wants the charge lead not to be hot when the key is on then a relay can be installed in the engine compartment between the charge lead and the fuse box post it connects to.

 

[Diamondpilot]

As I stated before and Matthew backed me up that on GM products the trailer plug charge lead is a separate circuit connected to the under hood fuse box. If the fuse is installed the charge lead on the trailer plug is hot whether the key is on or off. There are no relays or anything else in line to turn it off. If someone who owns a GM wants the charge lead not to be hot when the key is on then a relay can be installed in the engine compartment between the charge lead and the fuse box post it connects to.

I just walked next door with my test light and my 7 round tester and check my neighbors 2007 3500 Dmax SRW 4x4 in Classic trim, same truck as Builders. His pin #1 is 12 volt and #4 is ground as is standard now days. No power with key off, as soon as he turned the key to simulate the truck is running my light lit up. I also check it with my trailer plug tester for 7 Round and the same result was seen. There must not be any consistency in GM products if you guys are seeing different and I think it would be crazy to want it hot all the time, it will lead to problems of drained batteries. I can tell you for sure all Fords 1997 and newer are wired the correct way with a relay included to kill power when the truck is not running. 75% of the customers I have drive Fords so I deal with dozens of them each year.

Just to confirm I check my 2004 and 2006 SuperDuties and my new Titan and no power with the key off on any of the 3. As soon as the key was moved to the start position power was observed on all 3 via the 7 pin tester and confirmed with the lest light.

Chris