Is It Normal For 12v Power To Be On The Trailer Side 7-Way Plug When Disconnected
Question:
Should I see 12v at travel trailer 7 pin plug, not connected to vehicle? I suspect my trailer batteries are draining from towing. Is this plausible assumption?
asked by: Phil
Expert Reply:
Hey Phil,
It's ok to see 12 volts on one specific pin (pictured below). It means that whoever wired it ran a line to the battery so that the 12v hot pin on your tow vehicle's 7-way can charge the trailer battery a bit while you tow. Power sitting in the wire can drain the battery but it's such a low amount that it would take a long time to really drain the battery. Typically on trailers there's a lot of other appliances (lights, monitors, etc.) that have a small drain which all together end up draining a sitting trailer battery over a month or two.
You can install a battery disconnect like # SE56VR to help prevent battery drain while your trailer is sitting in storage. I also recommend picking up a small solar panel like the Optimate # MA49JR that you can throw on the trailer tongue to keep the battery charged up while in storage.
(click to enlarge)
Products Referenced in This Question
OptiMate Solar Duo Roof Mount Solar Charging System with Controller - 10 Watt Solar Panel
- RV Solar Panels
- Roof Mounted Solar Kit
- Rigid Panels
- 10 Watts
- 0.1 - 5 Amps
- AGM
- Flooded Lead Acid
- Gel
- Lithium - liFePO4
- 15-1/4L x 10W Inch
- 1 Panel
- OptiMate
more information >
Seaflo Battery Selector Switch for Boats and RVs - 6V, 12V, 24V, and 32V
- Accessories and Parts
- Battery
- Disconnect Switch
- Seaflo
more information >
Product Page this Question was Asked From
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Converter
- Custom Fit
- 4 Flat
- Tekonsha
more information >
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