Continuous Issues re eBrake and Windows

scottevest

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I spoke too soon. This am, the red light was on just like before, for about first 5 minutes. The shop said this was taken care of by bolting the alternator down. The windows all are super speedy, so not sure if this is a big deal or not.
 

teahead

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when the light is on, what voltage is it running (put a multimeter across the battery)?

when the light is off, ditto.
 

HB Chris

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Driving with the red light on means the alternator is not charging the battery sufficiently and you will drain your battery. With the multimeter set on 20V you should see a little over 14 volts on your meter with motor running, if less it is not producing enough output. With motor off you should see 12.6V on the battery.
 

Cornishman

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Scott
I can’t help thinking that you need a new workshop, or to sell the entire car to me

Seriously, I think this car could be fixed with a WatsAp video call between someone who knows E9s and someone who is able to follow instructions and has a few tools.

I would be surprised if Jaymic in the U.K. don’t have the hand brake cables, but they won’t be on their web page, so call them.

Wishing you the best of luck with the next fix.
 

Ohmess

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Cornishman - these problems are not e9 specific. I was addressing similar ebrake problem and alternator problems on my own junky US cars in the 1970s. Most of the blue collar guys in the part of the rust belt I grew up in would fix these types of things themselves. Other than a test meter, they don't even require specialized tools. Any competent mechanic should be able to fix these problems. Of course, part of the problem is that lots of people working as "mechanics" today don't know automotive systems, they know check engine lights and engine codes.
 

Arde

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Here is a dissertation I wrote for the Lancia board on alternator issues. It is a thought experiment from reading circuits and playing a bit with a bad Lancia alternator which I replaced with SFDon's help. Now you can tackle your red light on your own and ignore the shop...

In general the alternator rotor is excited by the current going from the battery through the charge bulb in the dash just to get some magnetic field before the alternator is producing any. The rotor is also excited by the output of the alternator itself so once it starts it self-sustains without pushing too much current through the bulb.
When the alternator voltage is above the battery voltage both sides of the bulb are at equal voltage because all involved diodes are conducting. The light should be OFF. If the light is OFF all the time it may be that the bulb is burned or that the rotor coil is open. The bulb wire by convention should be the only BLUE wire in the engine bay, so one can disconnect the blue wire (on the side that is not the alternator) and connect it to the battery. The alternator rotor is now excited even with a burned bulb and one can drive the car. If the rotor coil is open this will not help. An open rotor can be diagnosed by grounding the alternator side of the blue wire by observing the bulb does come on.

The voltage regulator is always a suspect when things do not work right, that is because it can interrupt the rotor current on its own, that is how it regulates (by modulating the average rotor current). I think one can briefly bypass the voltage regulator at low revs to diagnose things, namely to confirm a new one is needed.

The battery is used just for starting the engine and from then on it is the alternator providing the current, but maybe there are some subtleties there I miss.

A bulb that stays on solid while the engine is running could be explained if some of the diodes are shot open (as in not conducting). I guess a bad Voltage Regulator could also cause that if it operated erratically (sometimes charging the battery and sometimes regulating well below).
 

scottevest

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Per Bill Arnold:
Hi Scott,

The only jets that tend to get clogged are the idle jets...Which cause the engine to want to stall. The main jets almost never clog up due to being a much larger size. If the idle jets are clogged, you should check to see how much dirt is in your fuel filter. The jets are brass and do not corrode. The idle passageways in the carb bodies can get dirty...With the idle jets removed I usually blow them out with compressed air.

Hope this helps,
Bill Arnold

--
Bill Arnold

Bill Arnold Independent BMW Repair
 
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