Question on BMW 3-Series Electrical Problems

I have recently discovered the plug to my blower motor was charred and performed the repairs myself. Cut off the old wiring and spliced new wires and plug to the unit. I was pleased to find the motor working but since have a rough start at the crank. You mention checking the blower motor wiring for continuity in this article which makes me think I could have done something wrong. Any ideas as to what may be causing my rough start or could it be something else and just a coincidence? Any insight is truly appreciated!

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[Nick at Pelican Parts]

I would say coincidence, not sure how the two could be related.

When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and fuel pressure, volume, quality and engine compression. Are there any fault codes?

- Nick

[Dsgstp8d]

Hi Nick- Thanks for the response however I must apologize and say I was not clear in my initial question. When I said the car is having a rough start, I meant to say that it seems as if the battery is low and its straining to start the car. The battery was replaced only 18months ago so I that's why I'm thinking that something I may have done is now affecting the cars ability to start. Some notes I may add- when I spliced the existing wire to the new wire, I noticed about 3-4 tiny strands of wire were cut off with the insulation when I stripped the existing wire. I used high quality butt connectors to splice the wires together and no electrical wire is exposed anywhere. Also, I discovered that I had not retightened the negative battery terminal all the way. I noticed this about a week after I performed the repairs and the problem started. I had initially unplugged it to perform the repairs. I have since retightened it and its still sounds like the battery is dying when I start the car. Sorry for the lengthy post and look forward to any help you may offer. Thanks!!

[Dsgstp8d]

Hi Nick- Thanks for the response but I must apologize I don't think I described the problem accurately. The rough start I refer to is as if the battery is dying but its only 18 months old which is why I think I may have done something wrong. Some notes I may add- when I stripped the insulation of the existing wire to splice into the new wire, I noticed 3-4 tiny strands of wire which came off with the insulation. I used high quality butt connectors to splice the existing wire with the new wire and there is no exposed electrical copper wire anywhere that could be touching something else it shouldn't be. I have read that if you don't make a clean strip of the insulation and you take off some strands of wire that there could be negative affects on the electrical resistance? Just not sure if that would have anything to do with the problem I'm having. Also, after I noticed this problem of the rough start, I double checked the negative battery cable and discovered that I had not tightened it all the way after disconnecting it to perform the repairs. I retightened it and the problem still exists however doesn't seem to be as bad. Could this have had an effect on this issue? There are no warning lights nor have there been any other electrical problems. Any insight on what I could be the problem would be greatly appreciated. Thanks!!

[shogun]

It is easier to help when you post the model, built year and month, then we can check the wiring diagrams.

[Dsgstp8d]

It is an 07 335 e92. Sorry but I don't know the build year/month.