I am a Neanderthal. I trust nothing. Until I changed (toad) to 100% LED's I would give the vehicle a Monday morning walk-around with flasher and tail lights energized. Then a routine springtime bulb turnaround including third brake light. Rationale? Someone bashing into me because a front or rear burnout caused a no flash. Every time the OEM flasher seemed to indicate a burned out bulb it was during the first 10% of a long commute.
CORRECT LED lamps plus a rather pricey Sure Power burnout proof flasher solved that problem. But I still perform my Monday morning walk-arounds.
Quicksilver has 24-volt lighting so it uses much more reliable (1157-style 24-volt bulbs) Since I no longer drive after sundown the headlight issue is moot. The bus utilizes a motorized flasher. It has four tail/stop lights but the rear alternating flashing lights were welded and finished over.
If you need resistors, research their value meaning specifications then buy metal aluminum heatsinked resistors on eBay. One tenth the cost and ten thousand percent better quality than what is sold in kits.
BUT
BCM Body control modules on brand new vehicles makes choosing aftermarket lamps more critical. Research before you buy or modify.