trailer brakes

[GMCdiesel]

Will trailer brakes work if I don't have trans in tow/haul mode?Truck is 2015 GMC sierra.

[doc73]

Yes. They work when plugged into truck. Trans mode just changes some internal settings of shifting stuff. Your brakes are controlled by the brake controller. For me built in, if after market mine were always wired to the brake light wire / switch on the pedal.
Have a 15 Chevy HD
Sent from my Samsung Galaxy S7

[f5moab]

Also tow-haul mode will signal the TV's computer to increase voltage to help charge (keep charged) the trailer's battery(ies).

[dcheatwood]

Originally Posted by f5moab

Also tow-haul mode will signal the TV's computer to increase voltage to help charge (keep charged) the trailer's battery(ies).

Interesting. Did not know that. Thanks.

[f5moab]

From a 2015 Silverado owner's manual (GMC would be the same, just a different name); page 9-93

If charging a remote (non-vehicle)
battery, press the Tow/Haul Mode
button, if equipped, at the end of the
shift lever. This will boost the
vehicle system voltage and properly
charge the battery. If the trailer is
too light for Tow/Haul Mode, or the
vehicle is not equipped with Tow/
Haul, turn on the headlamps as a
second way to boost the vehicle
system and charge the battery.


Since I tow a 3200 lb popup, I do not use tow/haul mode, but I do run with the headlamps on. Not just to charge the battery, but to light up all the lights on the trail.

Toyota might do the same????

[dcheatwood]

I'll have to check that out. 😱

[rockfordroo]

Originally Posted by f5moab

Also tow-haul mode will signal the TV's computer to increase voltage to help charge (keep charged) the trailer's battery(ies).

Also changes your turn signals from 3 flashes to 6 flashes if you just touch the stalk.

[Big Red and 30WR]

Originally Posted by f5moab

Also tow-haul mode will signal the TV's computer to increase voltage to help charge (keep charged) the trailer's battery(ies).

Mine will charge the battery without using tow haul mode

[Hugeez]

Originally Posted by dcheatwood

Interesting. Did not know that. Thanks.

X2

[GMCdiesel]

Originally Posted by f5moab

From a 2015 Silverado owner's manual (GMC would be the same, just a different name); page 9-93

If charging a remote (non-vehicle)
battery, press the Tow/Haul Mode
button, if equipped, at the end of the
shift lever. This will boost the
vehicle system voltage and properly
charge the battery. If the trailer is
too light for Tow/Haul Mode, or the
vehicle is not equipped with Tow/
Haul, turn on the headlamps as a
second way to boost the vehicle
system and charge the battery.


Since I tow a 3200 lb popup, I do not use tow/haul mode, but I do run with the headlamps on. Not just to charge the battery, but to light up all the lights on the trail.

Toyota might do the same????

Thanks,I did not know that.
I do have utility trailer and it only weight 1,500 lb empty.

[f5moab]

Originally Posted by Big Red and 30WR

Mine will charge the battery without using tow haul mode

Your what?

On late model GM vehicles, the energy management system will drop the output voltage of the generator to around 12.9V after certain parameters are met such as set speed, battery fully charged, headlamps off, wipers off, etc. And while that can charge the trailer's battery it is not ideal.

The GM's computer does not monitor the trailers battery or voltage, so if traveling with 12V fridge running, you could discharge the battery while driving; I know I did it. That is when I called a GM engineer in MI and asked why my 2013 Silverado did not keep my batteries in the trailer charge. He noted to me to keep the headlamps on, or go into tow/haul mode. (And he also stated it is in the darn owner's manual so read the book.)

In tow/haul mode or when you turn on the headlamps, the computer regulates the voltage output to around 13.5 (something like that, I can always get the exact spec, just not this late at night-especially when a two-hour time difference between here and MI). Whatever the voltage is, it is enough to send higher voltage to the trailer batteries, and after that info was received, I have always run with the headlamps On (which also helps other vehicles to see the trailer since the lights are all on), and I have never had a dead set of trailer batteries after 8-16 hours driving with the fridge running on 12V.

I'll see if I can get him at work tomorrow and get him to email me some of the specs for how the system works.

[Phenom]

Originally Posted by f5moab

Your what?

On late model GM vehicles, the energy management system will drop the output voltage of the generator to around 12.9V after certain parameters are met such as set speed, battery fully charged, headlamps off, wipers off, etc. And while that can charge the trailer's battery it is not ideal.

The GM's computer does not monitor the trailers battery or voltage, so if traveling with 12V fridge running, you could discharge the battery while driving; I know I did it. That is when I called a GM engineer in MI and asked why my 2013 Silverado did not keep my batteries in the trailer charge. He noted to me to keep the headlamps on, or go into tow/haul mode. (And he also stated it is in the darn owner's manual so read the book.)

In tow/haul mode or when you turn on the headlamps, the computer regulates the voltage output to around 13.5 (something like that, I can always get the exact spec, just not this late at night-especially when a two-hour time difference between here and MI). Whatever the voltage is, it is enough to send higher voltage to the trailer batteries, and after that info was received, I have always run with the headlamps On (which also helps other vehicles to see the trailer since the lights are all on), and I have never had a dead set of trailer batteries after 8-16 hours driving with the fridge running on 12V.

I'll see if I can get him at work tomorrow and get him to email me some of the specs for how the system works.

This is interesting as I've been thinking about whether or not I could run my fridge on electric only while on the road. I've been running the propane, but electric would be better. Have a long day on the road coming up this week and was considering it.

[Big Red and 30WR]

Didn`t realize this thread was for GM only.

[jeff64]

Originally Posted by Phenom

This is interesting as I've been thinking about whether or not I could run my fridge on electric only while on the road. I've been running the propane, but electric would be better. Have a long day on the road coming up this week and was considering it.

Hard to believe you have 3 way power on the refer in a TT. Mine's 120vac or propane only. The 12 vdc is for the control circuits to switch it to propane

[Witch Doctor]

One thing to remember is that your alternator could supply 13.5 volts , but you are more concerned about the amps. Your amperage is still going to drop because of the wire size going to your trailer plug on the TV. I don't care if your in toe mode or drive with your headlights on, that wire can only supply so much amperage. Volts yes, amperage no. Unless your TV charge wire is larger, other then that it's only a trickle charge....

[Phenom]

Originally Posted by jeff64

Hard to believe you have 3 way power on the refer in a TT. Mine's 120vac or propane only. The 12 vdc is for the control circuits to switch it to propane

Good point. Disregard.