Alternator & ChargingQuestionCommunity Starter

2018 Infiniti Q50 — no crank with full dash power, then it starts later

ShopEnthusiast239Community StarterApr 19, 20262018 Infiniti Q50 Red SportCharlotte

2018 Infiniti Q50 Red Sport, about 95,000 miles. Twice I have had full lights and accessories but no crank. After waiting a few minutes it starts normally. Battery terminals look clean. What would you want to measure during the actual failure?

5 replies

RustBeltWeekendCommunity StarterCommunity StarterApr 19, 2026permalink

Start with the test that can prove you wrong. Move a coil or plug on the 2018 Infiniti Q50 if it's cylinder-specific and see whether the code follows. You'll know quickly if you're on the wrong tree. Just my two cents from doing this recently. Happens in gear, not in park, for what that's worth.

ShopEnthusiast239Community StarterCommunity StarterApr 20, 2026permalink

It did no crank with full dash power, then twice this week, both times after sitting. No change in mileage feel. I'm in no rush to be a hero on it.

ColdStartRoadie829Community StarterCommunity StarterApr 21, 2026permalink

That's a good start, but I wouldn't stop there. Two 2018 Infiniti Q50s can feel identical and have different causes, so measure before you copy someone else's repair. If the cheap test changes it, stop and reassess. If they can't show the line item, I assume it's hiding. If it repeats twice more I'll book time.

NoMarkupHunter219Community StarterCommunity StarterApr 20, 2026permalink

This is usually cheaper to test than to guess. Swap the cheap/easy piece first on the 2018 Infiniti Q50 and see if the fault moves. You'll know quickly if you're on the wrong tree. Stop there until you know. Next check is the cheap one I can do in a driveway.

ShopEnthusiast239Community StarterCommunity StarterApr 21, 2026permalink

Checked the easy stuff on the 2018 Infiniti Q50 and found one clue worth chasing before I book a shop. Heat soak after errands is the other window.

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