wdk450
Well-known member
Checking trailer battery charging
RalphPam:
To see if your truck is charging the trailer battery (which it MUST do for safety's sake with electric trailer brakes):
With the trailer disconnected from A.C. power
1) Connect a Digital Voltmeter set to measure 12 volts DC to your trailer battery. The reading disconnected from the truck should be about 12.6 volts.
2) Connect your umbilical cable from the trailer to the truck and start the truck engine. The reading on the trailer battery voltmeter should rise to about 13.6 volts if the truck is charging the trailer battery.
RalphPam:
To see if your truck is charging the trailer battery (which it MUST do for safety's sake with electric trailer brakes):
With the trailer disconnected from A.C. power
1) Connect a Digital Voltmeter set to measure 12 volts DC to your trailer battery. The reading disconnected from the truck should be about 12.6 volts.
2) Connect your umbilical cable from the trailer to the truck and start the truck engine. The reading on the trailer battery voltmeter should rise to about 13.6 volts if the truck is charging the trailer battery.
jimtoo
Moderator
The trailer brakes are a completely different circuit from the one that charges the trailer battery in normal operation. Now if you have a problem and the breakaway switch for your trailer brakes is pulled, then you must have the trailer battery charged and hooked up to have the brakes applied in emergency situations.
Have you searched for a diagram of trailer plug wiring to check for voltage? If not, search for trailer plug wiring so you will know what terminal to check.
Jim M
Have you searched for a diagram of trailer plug wiring to check for voltage? If not, search for trailer plug wiring so you will know what terminal to check.
Jim M
truknutt
Committed Member
Ralphpam,
Here is a link that has pictures of both tow vehicle and trailer 7-pole RV connectors so you know which blades to jump across with your test light or multimeter. Blades 1 & 4 are Ground & Battery Charge, respectively. Pay attention to the notch location..I have had them at 12 o'clock and at 6 o'clock on my trucks.
Side note (from experience) make sure your truck's ignition is on!
(http://rvbasics.com/techtips/rv-travel-trailer-plug-wiring.html)
Good luck!
Here is a link that has pictures of both tow vehicle and trailer 7-pole RV connectors so you know which blades to jump across with your test light or multimeter. Blades 1 & 4 are Ground & Battery Charge, respectively. Pay attention to the notch location..I have had them at 12 o'clock and at 6 o'clock on my trucks.
Side note (from experience) make sure your truck's ignition is on!
(http://rvbasics.com/techtips/rv-travel-trailer-plug-wiring.html)
Good luck!
Are you sure it not charging off the TV when driving? As previously stated if all is wired correctly it should be charging. Also your trailer accessories should work off the truck batteries if your trailer batteries are dead. I recently had an experience where my Trailer batteries went flat when bringing in my slides, I plug in the truck to the trailer and all worked just fine. The truck batteries saved the day.
2010augusta
Well-known member
If the coach/house battery is dead, and the TV is hooked up, can the hydrulic landing gear be ran off the TV? can the genset be started of the TV? or do you need to change some wiring? I had a dead battery at the storage lot and had to idle for 30 minutes to charge the batteries up enough to do anything. It would be great if the acessories could work with out the coach batteries. any thoughts?
newbie
Northern Virginia
I have used my hydraulic landing gear (on truck power). I keep the truck running so I use the alternator's power and not the trucks batteries.
Yes, but keep the TV engine running, as I stated earlier, I had to use the TV to bring in my slides and it worked very well.
Shadowchek
Well-known member
If your 5ver batteries are really dead you may need to have a more direct connection from your tv battery to your 5ver Batteries to save time. Use some jumper cables. You can get a lot more power through the big wire on jumper cables than you can the one in your regular chord.
Greg
Greg
