alternator issue?

[ahlem]

I think I've joined the club of BMW owners with alternator related issues.
It's a 1990 535im with 314,000 miles. I just completed a trip of 1050 miles with no problems. Yesterday, after the car sat in 10 degree F weather over night, I went to run an errand. As I left the driveway, I felt a major brief stumble. It recovered quickly. Today it's 13 degrees F. I went to run an errand at night, radio started fluttering, dash lights dimmed, headlights seemed pretty dim, wipers ran very slow and didn't speed up with acceleration but did when I turned off the headlights. Before I left on my trip, I tightened the loose alternator belt. Tomorrow I plan on putting it on the charger and hope to get it to an auto parts store for the free load test. Any suggestions on what to do in what order? I will check the terminals when I pull the back seat. Voltage regulator perhaps? I don't know how many miles are on the alternator. The PO kept real accurate records so I will review them to see. Any ideas will be appreciated including location of components other than the battery, alternator and attached regulator. Are there suspect relays?

[tim eh?]

for now unlock your obc and keep an eye on the voltage test9

[632 Regal]

seems we almost need a forum dedicated to just alternator issues.. I have not seen so many at a time ever.

[ahlem]

Thanks for the info.
8.83 volts +/- a moving target.
What does that mean? My alternator is only putting out 8.83 volts?
A regulator gone bad? replace some brushes in the alternator?
Before I give the back seat a wedgie to get it out, is there a trick to it? I will now search the forum and probably find the answer. I need to get the car on the charger since I used my one last start to get it into the garage next to my other 2 project cars taking up my wife's parking spot. It's 9 degrees F outside. I barbequed chicken anyway.

[ahlem]

Update...
I removed the rear seat. The battery got an overnight 6 amp charge until morning. The battery checks at 12 v with an analog multi meter. Running, the battery checks at 12 v as well, not the 14+ you would expect. The B+ terminal at the back of the alternator shows 12 v and the D + shows 10 v both running.

Will a load test tell me if it's the alternator, or battery or regulator? Or just alternator or battery?

I hesitate to go the 2 miles in the dark with the headlights on to the Autozone even after 8 hours on the charger. I guess I can walk home in the cold.

Any thoughts???

[tim eh?]

Update...
I removed the rear seat. The battery got an overnight 6 amp charge until morning. The battery checks at 12 v with an analog multi meter. Running, the battery checks at 12 v as well, not the 14+ you would expect. The B+ terminal at the back of the alternator shows 12 v and the D + shows 10 v both running.

Will a load test tell me if it's the alternator, or battery or regulator? Or just alternator or battery?

I hesitate to go the 2 miles in the dark with the headlights on to the Autozone even after 8 hours on the charger. I guess I can walk home in the cold.

Any thoughts???

yes it should be higher

like... 12.0 volts or 12.4 volts?

you are not getting enough charge, sometimes older batteries won't hold more than a certain amount so it is hard to tell why at this point.

a load test would clear/point to your battery as suspect.

do you still get 8V on test#9 now when running?
it should match the reading on the battery... near it at least.

[ahlem]

The autozone lady confirmed a good battery and about 12 v coming out of the alternator. My Bentley manual says there are brushes that can be replaced in the voltage regulator. The parts are $16 on realoem. Is it worth it to go that route? finding them may be another story. A rebuilt alternator from Autozone is $129. Don't know what brand it will be. Is it worth finding a Bosch? I can't find the radio code. Do I try changing it hot and tape things up so no arcing? I saw a doodad that plugs into the cigarette lighter and has a 9 volt battery to keep from having to do the radio code thing with the dealer. With 315K miles I don't know if I will get 50K more out of the beast or not.

[tim eh?]

not sure about the radio code but

Is it worth finding a Bosch?

yes i think so

if you want to try changing the regulator and brushes i think shogun has some for sale

http://www.bimmernut.com/forum/showthread.php?t=39013

[shogun]

radio code

Updated by TSB #6502933729 Nov 1986.

The BMW anti-theft radio circuitry is designed to essentially render your radio unsalable if it is stolen. If the radio is subsequently electrically reconnected, it will not operate until a five-digit security code assigned to your radio is entered. The anti-theft features and operation are as follows:

After the ignition key is removed, the red "anti-theft" LED will continuously flash, drawing attention to this feature.
Should anyone, such as a thief, touch any push-button on the radio after the key is removed, the anti-theft inscription will flash and a warning tone will sound for 5 minutes or until the ignition is turned ON .
Should the voltage supply to the radio drop below 5 volts due to a dead battery, electrical repairs, or radio removal (such as theft), the radio will not function when voltage is restored. The word "code" will show in the display only.
The proper 5-digit code shown on the TWO CARDS SUPPLIED TO YOU must then be entered (using the proper number radio push-button selectors in the bottom row) when the radio is on and the display shows "code". If the correct code is not entered in three successive tries , the radio will not accept entry until the radio has been left on for one hour with the ignition ON . IMPORTANT: When entering 5-digit code number, be sure to complete sequence number of that 5-digit code. For example: Code No. sequence is 43215 and you mistakenly enter 42 instead of 3, continue the code number sequence of 215 to complete that entry. The radio will not operate and "code" will reappear in the display. Re-enter the correct number sequence of 43215 and operation of the radio will continue. The likelihood of guessing the correct code is extremely remote. The radio is, therefore, unsalable to a thief. NOTE: If an audible beep is heard while entering the 5-digit code, STOP immediately ! Begin entering the code again, starting with the first number of the 5-digit code.
The code card should be placed in your wallet, or with the vehicle title papers for security as deemed necessary by your individual needs.
Should radio or electrical repairs become necessary, please give the repairing facility the radio code number. If you do not, only authorized BMW dealer personnel can obtain the code from BMW.
Should you lose your code cards, contact the nearest BMW dealer who will then obtain your code from BMW. You may be charged for removal of the radio to ascertain the radio chassis number.
WARNING: FOR YOUR PROTECTION, CODES WILL NOT BE GIVEN OUT TO ANYONE UNDER ANY CIRCUMSTANCES OTHER THAN AUTHORIZED BMW DEALER PERSONNEL AFTER PROOF OF VEHICLE OWNERSHIP AND PROPER IDENTIFICATION IS ESTABLISHED.
Install the 2 enclosed warning decals in accordance with motor vehicle regulations.

[Bill R.]

one unit. 54.00 something from them. Or you can get the rebuilt alternator, its going to be a bosch or valeo most likely, not rebuilt by bosch or valeo but the quality on the autozone rebuilt alternators is much better than it used to be, I wouldn't hesitate to use one.

The autozone lady confirmed a good battery and about 12 v coming out of the alternator. My Bentley manual says there are brushes that can be replaced in the voltage regulator. The parts are $16 on realoem. Is it worth it to go that route? finding them may be another story. A rebuilt alternator from Autozone is $129. Don't know what brand it will be. Is it worth finding a Bosch? I can't find the radio code. Do I try changing it hot and tape things up so no arcing? I saw a doodad that plugs into the cigarette lighter and has a 9 volt battery to keep from having to do the radio code thing with the dealer. With 315K miles I don't know if I will get 50K more out of the beast or not.