No lights while towing - 7 pin issue?

System

This discussion was created from comments split from: Need advice on solar suitcase for T@B 320S.

Harwoodmary

Running lights- need some help here, friends. Took our Tab 320S 2018 for a test drive. The 7pt plug was not relaying power to running lights (brake, turn signals). This is a new development. Everything else is good. Thots?

pthomas745

Clean your 7 pin plug, first.  There are "contact cleaners" out there.

And a bunch of threads.

https://www.google.com/search?client=firefox-b-1-d&sxsrf=ALeKk03N1MM1LfECw8RhB725BZierUS1LA:1615477634662&ei=gjtKYKr2J5Th-gTI47boAw&q=no+running+lights+site:tab-rv.vanillacommunity.com&oq=no+running+lights+site:tab-rv.vanillacommunity.com&gs_lcp=Cgdnd3Mtd2l6EAM6BwgAEEcQsANQnhNY30VgsUxoAXACeACAAVWIAegRkgECMzSYAQCgAQGqAQdnd3Mtd2l6yAEEwAEB&sclient=gws-wiz&ved=0ahUKEwiqv7mUy6jvAhWUsJ4KHcixDT0Q4dUDCAw&uact=5

N7SHG_Ham

As said, clean, then determine if signal is getting to plug, kind of a divide and conquer method. If power is getting to plug and still no go after cleaning, then it is trailer someplace and if all lights are dead, then I would look for what is common which is probably the ground wire. All the pigtail wires go to a junction box near front exterior of trailer and that would be 1st place to look for wiring issues on trailer.

Hopefully just a cleaning of both ends of the seven way is all that is needed.

Denny16

Also check the TV connection, to make,sure it is clean and working properly.
Next is the junction box just under the front of the trailer.  You can run a continuity check with a meter between the 7-pin and the junction box connections.  My bet is the TV 7-pin has failed, not the trailer.
cheers 

MuttonChops

@Harwoodmary;  Any progress on resolving your running/turn signal light issue?

You did not comment on your tow vehicle make/model/year or if your 7-Pin was factory or aftermarket installed.  All items that could allow better advice on things to check out.

As an Example:  Most but not all vehicles have Fuses on the 7-Pin circuits . . . most common on factory installed 7-pins.

Denny16

Good point, Checking TV fuse is a grand idea.  The only time I had a similar issue with trailer lights not working, turned out to be the TV fuse on the factory 7-pin harness.
cheers

webers3

Invest in a 7 pin tester, you will quickly determine if it's the TV 7 pin connector problem, or not
https://www.amazon.com/MICTUNING-Blade-Trailer-Connector-Tester/dp/B07JKWKGFQ/ref=sr_1_2_sspa?crid=3HSCFWY8VOQX4&dchild=1&keywords=7+pin+trailer+tester&qid=1615727476&sprefix=7+pin,aps,179&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzOTg3QVo5M0I1VU9EJmVuY3J5cHRlZElkPUEwNDI0MTM1MzVJMUxKOUVDRDRLSSZlbmNyeXB0ZWRBZElkPUEwNjQ4MDg4MUpJQ0Q2M0I4STNEWSZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

Michigan_Mike

Always start at the source and work your way back to the trailer.  Voltage indicator, check battery fuse, connections made at (or behind) the 7 pin tow vehicle assembly, source wire frayed or cut under vehicle between battery and 7-pin connector, bad or loose splice, etc.  Most likely at the TV side and checking for voltage at the 7-pin TV assembly will tell a lot.