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Discussion Starter #1
i just changed out my alternator and the car is doing wierd thing like the gear light comes on and the battery light is flickering and the check engine light comes on and off and the radio will just turn off. do i need to reset the computer in the car or is there something more going on that i just don't know. so anything that you can tell me would be great. thanks alot :dunno: :mad: :confused:
 

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hopesbeemin325i said:
i just changed out my alternator and the car is doing wierd thing like the gear light comes on and the battery light is flickering and the check engine light comes on and off and the radio will just turn off. do i need to reset the computer in the car or is there something more going on that i just don't know. so anything that you can tell me would be great. thanks alot :dunno: :mad: :confused:
Hmm this sounds.. not good.

Get a voltmeter hooked up and see how it looks. Something with a needle will be best, but a digital one will work if you have to. Make sure it's putting out proper voltage, should be 13.6 or 13.8 if memory serves. Anywhere between 13-14 will be "ok."

Make sure the new Alternator is in fact capable of producing enough amperage for the car -- it should be rated equal or higher than whatever is stock. You didn't mention if it was just a straight replacement, or if you replaced it with something "else."

If you've got an "underdrive pully" on there, take it off and put the real pully back on.

Make sure the belt has proper tension. Too tight, and it's going to end up breaking. Too loose, and you'll learn soon enough -- having the headlights on or any appreciable electrical load will make a horrendous squeeling noise we've all heard at one time or another.
 

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Discussion Starter #3
well i replaced it with the bosch 80 amp and i was thinking of going with the 140amp. i think i want to kick myself now. i looked like the one i pulled out. i do have a sound system and i am running two amps off this as well. if and it never did this stuff before. is there anything else i should now and thanks for the help :thumbup:
 

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hopesbeemin325i said:
well i replaced it with the bosch 80 amp and i was thinking of going with the 140amp. i think i want to kick myself now. i looked like the one i pulled out. i do have a sound system and i am running two amps off this as well. if and it never did this stuff before. is there anything else i should now and thanks for the help :thumbup:
Nah all that's really important are that it's making the proper voltage, which just about any car alternator should, and that the amperage is sufficient to run everything in the car. The pullies are just a waste, pure and simple.

Go ahead and kick yourself, take it back, and get the 140.. the stock one is 115 I believe? The 140 will give you about 325W beyond stock to power your amps and so on. If that's not enough, you'll want to go with an even larger one.
 

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and someone said something about my volt regulator and there was no power getting back to the battery and i forgot to menchin that my batt is 1000 ca's. so if that matters to i don't know if you have anything else i would apreciate all of your help. helps alot thanks :thumbup:
 

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hopesbeemin325i said:
and someone said something about my volt regulator and there was no power getting back to the battery and i forgot to menchin that my batt is 1000 ca's. so if that matters to i don't know if you have anything else i would apreciate all of your help. helps alot thanks :thumbup:
The voltage regulator is integrated with the alternator and has been for quite a few years on most of them. This is the case with the Bosch used stock in the E36 as well.

I was mistaken about the 115A, 80A is the stock value, but like you said.. you're running additional audio amps and so on, so stock may not be cutting it. Move to a 90 or 100A alternator.

Unhook or power off your amps to see if the problem suddenly goes away -- if it does, bingo, definately you just don't have the amperage you need. If you continue to drive it in this condition, you're risking major damage to the electrical system.

A Bosch AL0739X is a plug-in replacement for the stock AL0749X, but can provide 140A instead of 80A -- an additional 800 watts or so beyond stock.
 

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Discussion Starter #7
hey thanks for the help i am not so good when it comes to the eletrical systems so thanks for anything and if you are thinking and you think of anything the new altenator comes in two days but if you think something else just get back to me thanks again
 

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hopesbeemin325i said:
hey thanks for the help i am not so good when it comes to the eletrical systems so thanks for anything and if you are thinking and you think of anything the new altenator comes in two days but if you think something else just get back to me thanks again
Nothing special comes to mind, just power off your stereo amps and live without them until the new alternator arrives. A lot of little things, and some big things, can fail if they are run under-voltage for long.

Electrical motors will just heat up and burn out instead of turning -- this means your air-vent fan, window motors, and so on. Don't use them until this is solved.

Relays will "open" cause the things next to them to stop functioning -- this means your ABS, headlights, and possibly even your ignition system.

These are the major things that come to mind, I'm sure there are others. Just avoid electrical loads beyond stock until the new alternator is installed. :)
 

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Discussion Starter #9
does the bigger alternators call for a differnet rotation then the smaller ones. someone was telling me they have a different rotation and it wouldn't work on my 93 4dr 325i. is this true, or are they jags. they gave me a bad alternator to begin with, thats were the problem started. :mad:
 

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hopesbeemin325i said:
does the bigger alternators call for a differnet rotation then the smaller ones. someone was telling me they have a different rotation and it wouldn't work on my 93 4dr 325i. is this true, or are they jags. they gave me a bad alternator to begin with, thats were the problem started. :mad:
That's just bogus. Almost (don't expect a marine alternator, or something for a high-rpm engine like an RX-7, etc) any alternator will work, and any RPM mismatch can be corrected with the proper pulley.

If you go to a manufacturer (say Bosch, again) and give them the year/make/model of your car, they'll give you a list of alternators that are swap-in replacements, such as the 140A I mentioned.
 

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Discussion Starter #11 (Edited)
i order another of the same and it gets here tomorrow i should have waited a day i guess. i got the same one and now i will go back to kicking myself. but would i have to call bosch to get the list cause i might just send this one back and see about the bigger ones
 

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I think you have an electrical problem verus a alter problems. Let me ask you couple of questions. 1. Why did you change the alternator? 2. Did this problem started ONCE you changed alternator? 3. What's the brand of alternator did you swap with?

But my overal saying is that, you have more germlins to worry about. You should first start and check your wiring. I heard and even witness some of the electical problems you encounter through my friends car. But relocated the problems by finding an expose wire that was rubbing other wire, hence causing a short circuit.

The expose wire was located in the trunk. As you open your trunk look at the wire harness that is attach the lever and it up and see if you will find any expose wire. Because over the years, by opening and closing the trunk. You wear out the protective coating and could expose some wiring to rubbing.


If all fail, I would recommend you take your car into a certified electrician and have them runs some test on your car.

Good luck with your issue..
 

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Discussion Starter #13
1. i changed it because i teted it and it was bad and then i tested the new and it was bad as well.
2. the problem sarted before i got the new one. it kind of just not started on mornig.
3. i switched it out with a bosch.

thanks i will look at those wires for sure to see if thats were it is at. someone did put my spoiler on wrong and it fell off and there are some holes on the top that maybe got some water in there would that do it. it has just been sitting in the front for days now and i just thought of those holes in the trunk. but i did cover them as well so they were only exsposed for a few days of rain. butt i get a new on the morrow so i will check it and put it in and hope we are good. tjanks again.
 
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