now im having charging problems too..HELP

[bmwrp8]

during warm up obc reads 13.87-14.02. normal operating temp. 13.55-13.71
a/c and lights on at idle 12.32-12.64. give it gas 12.64-13.01 sometimes 13.32. but when aux fan kicks high its 11.48- 12.00 wtf??. give it gas up to 12.46 only. any thoughts guys? have 115amp alt.

[Tiger]

Augh! Similar to Tim's problem. Follow Bentley's manual to diagnose your problem. The easiest thing to check is your battery charge light on your cluster... does it work with engine off and ignition to position 2?

What did you measure your voltage with?

[bmwrp8]

Augh! Similar to Tim's problem. Follow Bentley's manual to diagnose your problem. The easiest thing to check is your battery charge light on your cluster... does it work with engine off and ignition to position 2?

What did you measure your voltage with?

yup similar to tim's the charge light is working and turns offwhen you start the engine. Measured the voltage thru obc but hooked up a tester directly at the battery and almost has the same reading.

[tim eh?]

during warm up obc reads 13.87-14.02. normal operating temp. 13.55-13.71
a/c and lights on at idle 12.32-12.64. give it gas 12.64-13.01 sometimes 13.32. but when aux fan kicks high its 11.48- 12.00 wtf??. give it gas up to 12.46 only. any thoughts guys? have 115amp alt.

sounds like my problem exactly.

i haven't resolved it myself, trying to ride out winter so i can do a proper job when i do it.

but i am 99% certain it's the alternator charge wire or the connector to the starter.

i think the way to localize this would be this...

1) let the engine warm to the point that you lose charge.

2) measure voltage directly at alternator.
ie B+ (large terminal) at alt to ground.

3) compare this with reading directly on battery.

NB- do not do a resistance reading at this time it will hurt you/your machine.

if these don't match, the problem is somewhere between alternator and battery, which means either
a) battery+ clamp/terminal (x947)... make sure it is tight and the wire is clamped in there nicely
b) battery wire to connector (x964) in conduit under motor (see photo)
c) connector x964 itself
d) wire from alt B+ to connector
e) maybee the wire to the starter... is that possible you could lose that much current there?

here's my suspect area and what i believe is under there





here's my next step (e.t.install march 2009) those ring terminals were a giant PITA to find.



if you pull that wiring conduit apart i would sooo appreciate a photo or 2.

i'm out west right now... took my dad's car in for a leaky tire fix and quizzed the mechanic a bit. he says alt wire corrosion is fairly common in older cars abused by winters such as ours and that it's a good place to start and sound preventative maintenance anyway.

good luck and sympathies - tim

[Tiger]

You know... for everyone's and your sake, take the car into the BMW dealer and let them tell you what is wrong with the car. This way is much cheaper than the way Tim went through.

[bmwrp8]

thanks for the reply tim. I was about to pm you I saw my negative cable from the batt. to the chassis was worn out cracked so i hooked my jumper cable from the -batt. to chassis then tried if it had a difference in charging condition...none and still the same. I'll do what you just told me though and change the wires. batt.,alt.,starter. then cross my fingrs i'll take photo's of the wires while doing it

[bmwrp8]

You know... for everyone's and your sake, take the car into the BMW dealer and let them tell you what is wrong with the car. This way is much cheaper than the way Tim went through.

i'll change my cables first then if no change i'll do that. I changed my alt. 3x already with no luckk

[tim eh?]

thanks for the reply tim. I was about to pm you I saw my negative cable from the batt. to the chassis was worn out cracked so i hooked my jumper cable from the -batt. to chassis then tried if it had a difference in charging condition...none and still the same. I'll do what you just told me though and change the wires. batt.,alt.,starter. then cross my fingrs i'll take photo's of the wires while doing it

you are most welcome, i hope it helps.

iiwy i would replace those negative cables first anyway... much easier, very cheap to do and good maintenance anyway.

[tim eh?]

You know... for everyone's and your sake, take the car into the BMW dealer and let them tell you what is wrong with the car. This way is much cheaper than the way Tim went through.

honestly i haven't spent so much (yet) except for the alternator(s) and battery and it's not so bad having new parts there... just time (sooo much time).
aside from those i purchased 2 fusible links, battery terminals, some cable, and an unloader relay. total<$100 on those, the relay being the most expensive part.
now i have something to blame white/thinning hair on besides extended family

[Dave M]

honestly i haven't spent so much (yet) except for the alternator(s) and battery and it's not so bad having new parts there... just time (sooo much time).
aside from those i purchased 2 fusible links, battery terminals, some cable, and an unloader relay. total<$100 on those, the relay being the most expensive part.
now i have something to blame white/thinning hair on besides extended family

\

And, if we all went to the dealer, this place would be a ghost town

Keep up he good work,

Dave