Uploaded July 2026 | Updated September 2026, 3 hours ago
This Mercedes arrived with a serious electrical fault: the engine would not crank and not start and almost nothing inside the vehicle was working.
The Mercedes dealership charged the customer for a diagnosis and concluded that the problem had been caused by a retrofitted aftermarket multimedia system and ambient lighting.
The customer returned to the independent shop that installed the aftermarket equipment but they strongly disagreed. According to them, the fault was 100% unrelated to their work or any of the parts they fitted.
With two completely different diagnoses, the customer was left stuck in the middle and potentially facing a very expensive repair bill.
That’s where we come in.
In this video i provide an independent third opinion. Instead of guessing or replacing parts we follow the correct diagnostic process, study the symptoms, test the relevant systems and perform the measurements needed to identify the true cause of the crank-no-start and complete interior electrical failure.
Was the Mercedes dealership right to blame independent shop and the aftermarket multimedia system and ambient lights?
Or was the independent retrofit shop correct all along?
Watch until the end to see what our testing revealed and find out who got the diagnosis right.
Let us know in the comments who you believed before the final result was revealed.
Subscribe for more real-world vehicle diagnostics, electrical fault finding, diagnosis checks, crank no-start investigations and faultfinding.
#Mercedes #MercedesDiagnosis #CrankNoStart #scantool #car diagnostics #car repair #mechanic
Check out my Second channel;
/ @ddtsb
Check out my website ; diagnosedan.com
For Diagnosedan Tsb visit : https://www.diagnosedan.com/diagnosed...
For the Topdon tool used in the video:
US: topdon.us
UK: diagnosticconnections.co.uk
EU: eu.topdon.com
For business inquiries ( not for technical questions!); Diagnosedan@gmail.com or fill out the contact form at Diagnosedan.com
This Mercedes arrived with a serious electrical fault: the engine would not crank and not start and almost nothing inside the vehicle was working.
The Mercedes dealership charged the customer for a diagnosis and concluded that the problem had been caused by a retrofitted aftermarket multimedia system and ambient lighting.
The customer returned to the independent shop that installed the aftermarket equipment but they strongly disagreed. According to them, the fault was 100% unrelated to their work or any of the parts they fitted.
With two completely different diagnoses, the customer was left stuck in the middle and potentially facing a very expensive repair bill.
That’s where we come in.
In this video i provide an independent third opinion. Instead of guessing or replacing parts we follow the correct diagnostic process, study the symptoms, test the relevant systems and perform the measurements needed to identify the true cause of the crank-no-start and complete interior electrical failure.
Was the Mercedes dealership right to blame independent shop and the aftermarket multimedia system and ambient lights?
Or was the independent retrofit shop correct all along?
Watch until the end to see what our testing revealed and find out who got the diagnosis right.
Let us know in the comments who you believed before the final result was revealed.
Subscribe for more real-world vehicle diagnostics, electrical fault finding, diagnosis checks, crank no-start investigations and faultfinding.
#Mercedes #MercedesDiagnosis #CrankNoStart #scantool #car diagnostics #car repair #mechanic
Check out my Second channel;
/ @ddtsb
Check out my website ; diagnosedan.com
For Diagnosedan Tsb visit : https://www.diagnosedan.com/diagnosed...
For the Topdon tool used in the video:
US: topdon.us
UK: diagnosticconnections.co.uk
EU: eu.topdon.com
For business inquiries ( not for technical questions!); Diagnosedan@gmail.com or fill out the contact form at Diagnosedan.com
