5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
Recently came into this car due to the previous owner couldn't get anyony to fix it.
It wont charge..New alt.New battery previous owner bought.I took the alt. down and had it tested thinking it could be bad but it is good.Can anyone please tell me what to check.I'm thinking it could be shorting from the B wire on the alt back to the + junction cause when I checked it for continuity I accidently touched one lead to ground and it showed continuity..There shouldn't be cont. from this wire to ground should there.Any help would be greatly appreciated.
If you charge the battery and connect it to the car, does it discharge on its own fairly quickly, or is there a near zero drain on it when the car is turned off?
If you connect a test lead to the output of the alternator (not the cars harness) and start the car, does it produce 12 - 14 volts as expected?
The lead that goes from the alternator to the battery should not go to ground, if it does, the battery will drain quickly and probably spark when you connect it to the car.
Check the insulation along the wire and the jumper post (if you have that on your motor)
One further thought, do you have multiple leads attaching to the alternator output? If you do, check each one of these for being a source of your grounding. Maybe someone reconnected that wire incorrectly when the alternator was replaced.
I fully charged it and it lost about 1 volt overnight..Is that to much for these cars?
I just went out and disconnected the battery to see if it sparks when it is hooked up and it does a little bit..Also funny thing happens..When I re attach the cables the flashers come on.I tried it several times and each time they came on and I had to push the flasher button two times to turn them off.
I have not got the alt back on from having it tested.I will attempt to get it together tomorrow and will report back if I am getting 14 volt output.
I will also verify if the alt output wire is grounding..Wonder how I will access it.It seems to go under the intake somehow.
If you are getting a lot of sparking when you connect the battery it shows a reasonable load on connection. The flashers may be the normal response from the alarm system, and if it works normally once you have it all connected I wouldn't be too worried about it. 1 Volt over night isn't too much of a load, and probably ok, I wouldn't expect a battery to be holding any charge after 12 hours if you have a ground short in the system. If you put an Multimeter (AMP Setting) between the battery + post and the + post clamp you should be able to measure what current is being drawn with the car off.
Does the alternator lead go under the intake manifold or just a manfold cover?
Are there multiple seperate wires that connect to the 12v output on the Alternator?
Thanks..Seems I was mistaken on the alt. output wire going to ground.I don't believe it is.The output wire stops at + junction on the firewall.Pic attached..The top red wire is the alt output end.I got alt back on today but didn't get it all back together.//After I got the alt back on and hooked up I put my multi meter on it and got battery voltage from the B post..I didn't get any voltage from the D terminal..With the ignition on..Shouldn't I get battery voltage from that D terminal with the key on..//I can't follow the alt output wires path but I got continuity from the bottom end to the top wire in that pic so I know it is it's other end..//Can you tell me What that gray connection is in the pic..It is just hanging under the hood not connected..I can't find anywhere that looks like it was connected to.Thanks...I have got a new belt tensioner ordered which should be here Wed.I noticed when I took it apart that the belt was kinda loose..Tensioner looks to be original equip.
You should have battery voltage at the D wire with key on.Also you should make sure the fuses are ok for that circuit.#28&17 on my 94.And make sure your defogger/sunroof work....if not.. the unloader relay may be in question.It's a purple relay in the center closest to the fuses.Good luck.
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