ScannerDanner finds a loose magnet behind a Navigator's no-start
The crank sensor case study joins a trailer-brake lesson in a two-upload week.
Why this story? The channel's weekly summary: what went up this week, what is drawing views now, and where the channel stands among similar channels.
I've NEVER Seen a Crank Sensor Fail Like This!
Things we can learn from the video
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- 1:16No tachometer movement and an illuminated check engine light during cranking point toward a missing crank signal.
- 7:35The oscilloscope shows only a single pulse per rotation instead of the expected crank sensor pattern.
- 15:57A magnet retrieves the sensor's detached magnet from the trigger wheel.
- 21:36The Navigator starts after the loose magnet is removed and the crank sensor replaced.
- 26:05Moving a scope lead to chassis ground demonstrates why the floating-ground connection halves the measured amplitude.
The trouble codes pointed toward camshaft sensors. ScannerDanner followed a different clue: a Lincoln Navigator that cranked without moving its tachometer or registering engine speed on the scan tool.
That decision anchors "I've NEVER Seen a Crank Sensor Fail Like This!", the week's most-watched new upload, with roughly 25,000 views. Working with his brother Bo, he finds a crankshaft sensor signal producing just a single pulse per revolution rather than the expected pattern. Then the borescope supplies the explanation: the sensor's magnet has broken off and attached itself to the rotating trigger wheel.
It's a particularly concrete example of the channel's test-before-guessing approach. Replacing the sensor alone would have left the loose magnet inside. After extracting it and installing the replacement, ScannerDanner gets the engine running and returns to the oscilloscope to show what a healthy signal looks like. Viewers are discussing adding a borescope inspection to their checks; another admits the tool mostly earns its keep retrieving dropped bolts.
The other new upload, "Trailer Brake Control Module Feedback Signals", has the strongest daily viewing among the channel's videos right now, followed by the Navigator case and the older "Honda Accord LOW POWER Condition - Follow Up!".
Across the catalog, the week brought about 143,000 views, while subscribers held steady. Daily viewing is below the channel's usual pace. Nearby motoring channels have had varied weeks: High Peak Autos drew a substantial weekly audience, while Drift Games' daily viewing is running above its norm.
For ScannerDanner, the useful payoff comes after the Navigator starts: changing the scope connection demonstrates how a floating ground can halve the measured signal amplitude. Finding the fault becomes a lesson in measuring the next one.
Published on Trari
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What viewers say
I use my bore scope almost every day.... mostly because I drop tools and bolts so often lol
@albinorhino1341See it on YouTubeWow. You could add the borescope inspection to your normal checking procedures before putting a new crank or cam position sensor back in.
@troycarothers8254See it on YouTubeGreat job team Danner! That magnet could have damaged the new crank sensor and sent you down a rabbit hole!
@daigrt770See it on YouTube
4 more comments
I used your dome light trick the other day! I had a metris no start. I hit the dome light and cranked it the light did not dim! Went straight for ignition switch and cleaned the dirt/dust off the circuit board/photo sensors. Fixed it quick and easy. Thank you!
@12v_DiagnosticsSee it on YouTubeSuch thoroughness is always inspiring! Thanks Paul.
@bobflannagan7262See it on YouTubeGreat video as always. Attention to detail is so important. Thanks for sharing.
@tonymigliorini9526See it on YouTubeI wasnt expect to see that kind of crank sensor problem 😂 . great video sir ❤
@Savindu-l1eSee it on YouTube
Public comments from the video's page on YouTube
The videos drawing views on ScannerDanner right now
- Channel
- ScannerDanner
- Subscribers
- 501,000
- Channel views, last 7 days
- 142,912
- Videos published this week
- 2
- Video published
- October 31, 2026
- Video views so far
- 24,541
- Views on its first day
- 11,963
The numbers
Here is ScannerDanner's week in views, subscribers and uploads.
💡 Test your knowledge
Which vehicle does ScannerDanner diagnose in the crank sensor case study?
The case study follows a 2012 Lincoln Navigator that cranks but will not start.




