1998 Dodge Ram 2500 backup lights

What have you tried? Have you checked the bulbs?

If the bulbs are good, suspect the neutral safety switch. Here's a quick way to verify it's the problem. Turn the ignition switch to "run". You can leave it in park. Crawl underneath and unplug the neutral safety switch. It's on the left side of the transmission, above the middle of the pan, and has a three-wire plug. (Could be closer to the rear corner of the pan. I can't remember). Use a stretched out paper clip, cotter pin, or piece of wire to connect the two outer terminals in the connector. Watch very closely when you make the connection to the second terminal. If you see a little spark, that means current is flowing to at least one of the backup light bulbs. That indicates the switch is defective. You can also jump out and look at the bulbs to prove they're working.

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