Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
You're right about your truck not having an old-style flasher, the body control module (BCM) handles that task now. The turn signals will work correctly as long as the BCM detects the same electrical loads as it did with the original bulbs. An LED bulb represents a much smaller electrical load than the original incandescent bulb, so a load resistor must be added to the circuit to match the original electrical load the BCM will recognize.
In conclusion, one LED bulb plus one resistor equal one original incandescent bulb.
Please let me know if you're doing this yourself and need help with the electrical installation.