Review on CEC Industries EF32RL Flasher by Chris Ostby

At first they didn't work because my truck had reverse polarity for the factory thermal flashers. Rather than returning them and ordering EF32RLNP turn signals I swapped the wires in the fuse/relay box (not too hard) and we'll be back in business once I find a good ground for the ground wires. My truck has two turn signals - one for the alarm system, one for the turn signals. I installed LASFIT 3157 LED bulbs https://www.amazon.com/gp/product/B076J6CJTP/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1), front yellow/rear red and WOW, they are bright and the flashing frequency is right . If you're not that fearless with the wiring, just get the EF32RLNP blocks and don't worry - they're polarity independent.