have 05CTT.
It has a hitch and wiring installed (I think from factory since it was not even used until I looked at it).
Wanted to use it, so unscrewed the little cover that covers the connector side of the wiring next to the hitch.
Was a 7 blade connection.
Went to autozone, bought the Hopking #426515 wiring kit (7 blade plus 4 straight connector).
The connector plugged right into the connection on the car once i removed the cover.
Friend brought a small trailer over. All lighting works on his car just fine.
When i plugged the wiring to my car, I saw an error on my cluster saying check the trailer tail lights.
When checking, the directional lights work (left, right, emergency).
The stop lights work fine when pressing brake.
The tail lights (ones that are supposed to be lit up when you turn on your headlights so other cars can see the trailer when driving), do not turn on.

Bought the little tester to test connection (little black plastic with LEDs), and it also says tail lights to indicate there is something wrong with them.

Any help will be appreciated.

 

Simple - you will need a 7-way to 4- pin converter that has built-in resisters for LED trailer lights. This is make the error message go away on the cluster. Something similar to this will work.

 

TThis is the connector i bought.

Click here

Can you explain why i would need to buy a 7 pin to 4 pin connector even though the one i have already has a 4 pin built in, in addition to the 7 pin?
Everything works but tail lights when i turn headlights on (for night driving). Trying to understand reasoning. Thanks for help in advance.

The tail lights in trailer are not LEDs. They are regular incadescent bulbs, but i checked and all seem to be fine, even friend's truck hookup alloqs ail lights to work.

 

I would look for a possible blown fuse. My 06 manual shows fuses for "towing attachment" in the right side of dashboard fuse box --fuses 1,3,5,41--all 15amp except 41 is 10 amp.

 

checked the fuses and they are fine (ones you mentioned). any other ideas? Maybe replace the connector? can it be faulty right out of the factory?

 

I wouldn't really expect the connector--it's just a straight thru device--the wiring harness hooks up to the backside and the trailer plug hooks up to the front side. Possibly the control unit (P/N 955 618 040 10 -a $150 part from the dealer) is bad --it's mounted in the right side rear fenderwell--under the cd changer if you have one. Maybe it's time to bite the bullet and have the stealer diagnose the problem?

 

Can anyone tell which of the four straight connections carries signal for tail lights? I will try to probe it to see if it is hot when headlights turn on. If yes, it will be something on trailer side. If i can find diagram of the 4 connections, it msy help

 

The standard pinout for a 4pin connector is:
Male pin=gnd next=tail next=left turn next=right turn

 

ciaka, i bought the same adapter you did and have no issues on my 06. maybe there is a fault in the adapter you bought? i would check continuity on all the pins to verify that while you are out probing..

 

Forgot to add this factory-style adapter in my original post, instead of the option you chose:

Pollak 11-893P 7-Way Sealed RV OEM Socket

 

crap, i didnt see those when i was hunting for something to use much cleaner than what ciaka and I have.

amazon prime $14 shipped

 

Yeah, sorry, I will be putting up a few stickies here shortly on this subsection. I will make sure to include this as well.

FWIW, I have had corrosion issues (on previous vehicles) with the versions with the built-in 4 pin connectors on the side. This sealed connection is much more waterproof than a rubber boot. Not to mention, that I add a liberal does of di-electric grease to the internal pins as added insurance.