2023 Toyota 4Runner — blower works on some speeds but not others

This is usually cheaper to test than to guess. Capture voltage while the 2023 Toyota 4Runner is actually failing — after it restarts you've lost the clue. You'll know quickly if you're on the wrong tree. Do that first. Only after sitting overnight so far.

Intermittent stuff lies if you only catch it once. Move a coil or plug on the 2023 Toyota 4Runner if it's cylinder-specific and see whether the code follows. Don't erase codes until someone who can help has seen them. On “blower works on some speeds but not,” that was the fork that mattered for me. Do that first. Climate here is different, so treat that as a local data point. If that fails I'll eat the diagnostic fee.