Could my LED lights be PWM /Multiplex?

[Buck9s]

I'm trying to install a 3rd brake light and side mirrors with turn signals in them. I purchased a Curt 2-to-3 Taillight Converter (56196) which is supposed to take the signal from your combined left & right brake/turn lights and separate the signal into 3 signals (Left, Brake, Right). After hooking everything up I'm not getting any signal output from the Curt converter.

I have a 2015 TXT 48V and the dealer I bought it from installed a full LED headlight/taillight set-up for me. My lights appear to be the "Premium E-Z-GO T48 GTW LED Light Kit (Fits 2014-Up)" kit.

After doing more research I've come to find that this Curt converter doesn't work with PWM/multiplex (Pulse Width Modulation system or a 'multiplex') LED systems. Could this LED system be PWM? If not, any other ideas why I'm not getting an output signal?

It looks like 16v are going in to the convertor but I'm getting 250mv constant output. I don't know enough to diagnose any further.