2001 540i No crank but Will bump start

[StoneyCreekE39]

Hey first post here just recently traded off a 2001 audi a4 sline I had mildly tuned for this 2001 540i m sport manual. Very fun car and I have been enjoying it. Car seemed to have been taken very good mechanical care of so I bit the bullet and made the trade. After driving for about a week I went to start the car to leave a friends house and I got no crank. I ended up bump starting the car to take it home and have not found out what is causing this yet. So far i have checked the fuse panels under the passenger seat, in the glove box and in the trunk with no seeming to be issues. Also I have refurbished the ignition switch using the sand paper method between the contacts and just today I deleted the clutch safety switch hoping that was the issue. Car has a brand new battery and before this the starter showed no sign of slow crank or being on its way out. Also tried the passenger sun viser open and some other tricks I read online. Kind of stumped and am wondering if any of you who may be more knowledgeable than me or know these older bmws better can help. I have a multi meter to test electronics and a full garage of tools, im not scared of testing and pulling this car apart. Please shoot me ideas.

[bmwdirtracer]

Welcome to the forum.

You really need to quit with the "tricks", sorry.

You can't "refurbish" an ignition swith by sanding the contacts. If you believe the ignition switch is bad, replace it, it's sixty bucks.
https://www.fcpeuro.com/products/bmw...-61326901961-1

That said, well, you have a multimeter....so does the activation wire go hot when you turn the key to start? If so, the ignition switch is not the problem.

Take your multimeter, and test whether the activation wire at the starter goes hot when someone turns the key to start position. If so, and if the main starter terminal has ~12.5 + volts, and if the engine is properly grounded at the passenger engine mount, then replace the starter.

The sunvisor trick is for checking whether strange, unrelated electrical issues are related to the ignition switch. It's not for starter problems.

I highly recommend against deleting the clutch safety switch; next you'll be wondering why your cruise control doesn't work.

[StoneyCreekE39]

Forgot to follow up on this. Turns out it was just the little copper power wire on my starter. Somehow it had corroded off both ends leaving me powerless. Felt stupid once i noticed it was missing but hey it was an easy fix with a replacement used starter. Thanks for the advice bmwdirtracer!

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