LED resistor needed?

JerseyGirl13

I have a 2021 T@B 400 BOONDOCK that I tow with my 2017 Audi Q5 with aftermarket tow package. The 7 pin has power but the T@B turn signals are not working. It was suggested by the tow installation technician it might need an LED resistor since camper safety lights are all LED. 
As background I will share that I towed it over 5 nights to Florida in January when i first got it without any issue. Then after spending winter in Floruda with it parked for 3 months I towed it on trip to Texas and on 4th day of trip there was no power going to 7 pin. Several technicians evaluated it and the only solution was to replace the ZCI interface. This failed to correct the problem so I left my trailer in Louisiana until a friend in Texas with a truck that had integrated tow package could tow it back to PA for me which he did without encountering any issue with the safety lights. When I got home the tech who installed the hitch package found that the ZCI replacement had been  installed incorrectly in Louisiana.  He installed it correctly and the 7 pin had power. (As a side note I returned the original ZCI SINCE it was under warranty and the manufacturer evaluated and found it was not defective so probably had not required replacement.) So i tried plugging my camper into the 7 pin last week in prep for an upcoming trip and all the camper lights worked. Yesterday I tried it again and only the brake lights worked. Thinking maybe the pins for the directional lights were dirty or bent I had the hitch guys check it again and the 7 pin is fine. Hence the suggestion for the LED resistor.
Does this situation seem familiar to anyone? If a resistor would correct this why was my friend able to tow it without issue without a resistor? Why are only the turn signals affected though I fear when I get to camground today to check again none of the lights will work. I am supposed to leave for a trip next week and lack confidence that I will not encounter an issue even if a resistor is installed. I have a concern that the real issue is that Audi has complicated electronics and I will continues to have issues with the aftermarket tow package. I am not ready to buy a new vehicle or sell my camper but may have an incompatible  situation. So back to the opening question. Do I need an LED resistor? Will that fix the recurring issue with camper safety lights? Thanks for reading this tale and any experience or advice you can offer.

MuttonChops

ZCI's get mixed reviews on how well they function.
ZCI == zero contact interface.  Are connected to the TV battery and use some type of sensing technology to monitor the TV stop/turn lights, ZCI then sends voltage to 7-pin.

If my TV; I would research brand of ZCI installed (is it LED lamp approved).
Would also consider a different brand ZCI.   And yet again have the entire installation detail checked for correctness including good wire connections (continuity).

Good luck,  Hope to hear about a positive outcome in near future.

JerseyGirl13

Thank you very much! I will check with tech who did installation about alternative ZCI.  

Grumpy_G

AFAIK the Q5 has LED tail lights and I suspect the ZCI does not get triggered reliably because of the comparably low current draw of LED lights. I assume the resistors they are talking about go in the tow vehicle to increase current draw. It probably works but is a bit of a hack in my world. There are similar products that protect the vehicle electronics but physically tap into the wires to sense the light status.