Have 2007 Ford Ranger XL 2.3L 4x2 and purchased these tail lights off Amazon...
I am aware of hyperlinking issues typically needing a resistor, but I don't think that is my issue.

With Headlights / Taillights turned off, when I indicate, the LED is very dim. I can see it flash, but only when my eyes are inches away from the tail light. So indicator is going, at expected speed, just very faint. And not bright enough to be usable on the road.

If I turn Headlights / Taillights on, when I indicate, the LED flashes are per normal expectation. So it's like the indicator needs the extra power from Headlights / Taillights being on to be able to light up the LEDs. And if Headlights / Taillights are turned off, there is just not enough power?

Any thoughts on what I need to do?

 

I read a post awhile back where the 3rd party tail lights were mis-wired

Just FYI, the parking light bulb is a lower wattage than brake or turn bulbs on all vehicles

Issue in the other post was in the 3rd party tail lights the park and turn LEDs were reversed, so the brake/turn were dim but park lights were bright, too bright

2000-2011 Ranger used the 2 wire system
Separate wire for Park lights, then 1 wire on each side that combined turn and brake

So first check if brake lights are bright, just put a stick on brake pedal to hold it down
Turn on the key, brake lights still on
Try a turn signal, the other sides brake light should still be on, and you should now see flashing turn light of same brightness as brake light on the side selected

The main light switch has no connection to brake lights or turn signal system, it is only connected to park lights and head lights
You can check if someone has added Trailer lights, these DIY connections can cause issues if they corroded or damage the factory wires when they were installed

And try the 4-way flashers, they use a different fuse for power but the same Flasher unit as the turn signals