I had to jam on breaks to keep from hiting a lady and it seems to have made my car go nuts.

I have a 1990 535I BMW. I had to jam on breaks to keep from hiting a lady and it seems to have made my car go nuts. Please help me with this question. Being a 78yr. old woman I had to admitt the woman driver does goe into the catagoary peple refer to about woman dirvers. My car cut off and would not start so they checked the alternator, which was ok, but I was told i may need to try a dioad or relay. Can you please tell me where in the car either of these are located? Thank you so much in advance for your help.
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This post was auto-generated based upon a question asked on our tech article page here:

[Nick at Pelican Parts]

Look under the hood and you should see a line that goes from your intake manifold to the brake booster. It might have come off or broke. This will cause hard starting and running and also disable your power brakes/

- Nick

[Manolito]

Could you tell us more about the symptoms you are experiencing?

You say the the car "cut off and would not start", but then you say that "they" (who?) checked your alternator. It must have been running when they checked your alternator. What is the car doing now that is a problem?

Depending on your symptoms, the diodes that are most likely of interest are the ones in the alternator, so if whoever checked the alternator could not check its diodes, they must not have been very well equipped. In any event, I would not expect a diode failure to coincide with slamming on the brakes.

The first thing I would look for after slamming on the brakes is a battery that broke loose and is now rattling around sparking. I am not familiar with your model, but I expect your battery should either be below the back seat (which just snaps up) or below the floor of your trunk on the right side. Make sure it is securely fixed in place and its cables are clean and tight.

The second thing to check is movement in the engine or transmission or rear end due to failed mounts. However, to speculate about those, we need to know the symptoms.