red warning light faint glow at >3200RPMS

[golf73]

i put a new alternator and belt in about 8 months ago, battery is a 6-year battery of unknown age. put in a new starter (smaller body replacement) last weekend. just noticed the faint light glowing on the highway the other day, but could have been there before as i might not have noticed. i was thinking of checking battery voltage at rest and then do a load test, checking it at RPM when light starts glowing - anything else? is this an obvious problem someone has experienced, or is there something i should check first?

[c.d.iesel]

= BAD Alternator DIODES = replace alternator

and do check yer battery voltage as you suspect also

[ChuckR]

do you have a multimeter? you can check the battery, and charging system - i forget what the reading should be off the top of my head, but if you searched the forum (or had a decent manual) you'd find some info (or you may know it already). i had same thing; faint glow, turned out to be my regulator. chuck

[Chris_B]

i put a new alternator and belt in about 8 months ago, battery is a 6-year battery of unknown age. put in a new starter (smaller body replacement) last weekend. just noticed the faint light glowing on the highway the other day, but could have been there before as i might not have noticed. i was thinking of checking battery voltage at rest and then do a load test, checking it at RPM when light starts glowing - anything else? is this an obvious problem someone has experienced, or is there something i should check first?

Likely, as the dude (CD) sez, you have a bad diode in the output stage of your alternator. Basically, the glowing light means that the power consumption in your charging system exceeds the power output, which could be the result of other problems like excessive resistance in the system (check connections at both ends- ground and power). Also, see http://www.bmw2002faq.com/images/stories/faqs/charging_system/02_charging.pdf

[Guest Anonymous]

Are you sure the idle jetting circuit doesn't cover this too? LOL!

(could not resist - having just read that thread!)

[Chris_B]

Reasonably sure, although one shouldn't leave any turn unstoned.