I recently bought a "new" (used) tow car (a 2010 Toyota RAV4 V6) which has the factory tow prep package on it. The package doesn't include the light
harness nor hitch, so I just had those put in at the dealer I bought it from. (It turns out they sent it out.)
I noticed that my trailer's turn signals, when attached to the new light
harness, work in unison with the car's. So do the tail lights
when the headlamps are on. But the emergency flashers only light
up on the trailer when I leave the key in the ignition in "accessory" position. If the key is out, the car's blinkers flash, but the trailer's don't.
I don't think it's the trailer as I don't remember anything like this before and also I have one of those red lights
you stick in your 2x 2" hitch receiver when you're not towing. It acts as an added brake light, etc. But it also only
flashes with the car's emergency flashers if the key is in the ignition.
Is this what is supposed to happen?
Last time I was at that dealer, the shop BS'd their way on a couple of other things, and since they didn't even put the harness in, I'm afraid they'll tell me yes that's the way it should be even if it isn't.