Stranded by Alternator failure?

[RobH]

I was on my way back from Houston to New Braunfels (my home) today and my 89 535i gauges went to 0 on I-10 West. I managed to get off I-10 onto the feeder and then a side street just as it died.

I checked my fuses and obvious connections and saw nothing. The car wouldn't even turn over until I removed and replaced fuse 20 (no idea if this was actually related...just the last thing it did before starting to do something) It started clicking like a dead battery...I was happy to get -something-. Got a jump from a friendly passer by and it seemed fine, but I had ABS and parking brake light on the dash illumated. It ran for about 45secs after we unhooked and started stuttering and had a fuel smell which I took to be from bad spark...from low voltage. Re-jumped to verify...same.

Talked to a couple of BMW places and we agreed it was alternator failure since we seemed to lose battery power (gauges ran fine during jump, went to 0 and dimmed before engine got rough).

Got and installed a new alternator on the side of the road. (must remember to carry a pair of jeans and t-shirt in the trunk...ruined slacks and dress shirt).

Finished, jumped, started...seemed good for 3 minutes...then the same slow failure. Charged for 15min and it ran longer...same symptoms....but the battery light is now on in the dash.

Could it be a bunk new alternator? I'm thinking not, my -guess- is that I've got a bad battery as well and the old alternator might not have been bad

I'm going to have the battery replaced in the morning I guess.

It is worth noting that I replaced my AC blower fan this past weekend and while I was quite careful I wonder if it could be related? The car ran Sunday - Thursday both day and night without anything bad...but it's a data point that could be related.

Thoughts anyone?

__
Rob (Stuck in a hotel for the night)

[ryan roopnarine]

at a DAP or AZ they can check the alternator output for you, as well as the batt health.....i don't know if this is the case or not, but my 525i has several sizes and amperages of alternator...maybe you got a smaller one?? i thought that the really small ones were implemented in only europe, but maybe one got propagated to a US parts catalogue.

[RobH]

at a DAP or AZ they can check the alternator output for you, as well as the batt health.....i don't know if this is the case or not, but my 525i has several sizes and amperages of alternator...maybe you got a smaller one?? i thought that the really small ones were implemented in only europe, but maybe one got propagated to a US parts catalogue.

There appears to be both 90 and 115 amp. I was sure to get a 115amp alternator. I've -heard- that it's probably due to a dead/shot battery which is "a bad thing" on a bimmer...even if the alternator is running 5x5. I'm -hoping- this is the case and not that I have a more obscure and painful issue.

I'll be at Pet Boys in the morning to verify battery, alternator and charge.

[bmwpower]

There appears to be both 90 and 115 amp. I was sure to get a 115amp alternator. I've -heard- that it's probably due to a dead/shot battery which is "a bad thing" on a bimmer...even if the alternator is running 5x5. I'm -hoping- this is the case and not that I have a more obscure and painful issue.

I'll be at Pet Boys in the morning to verify battery, alternator and charge.

You might want to try to get the correct voltage regulator. It's cheaper. But then again you have to dismantle the alternator some to get to the regulator. I have the 140amp on my 535i, so buying a new one was out of my price range. After the regulator installation, everything is up to spec.

[Bill R.]

connect a new alternator to a battery thats not charged up... Most of them have warning labels telling you to makesure that the battery is fully charged before installing the new alternator or failure can occur..

I was on my way back from Houston to New Braunfels (my home) today and my 89 535i gauges went to 0 on I-10 West. I managed to get off I-10 onto the feeder and then a side street just as it died.

I checked my fuses and obvious connections and saw nothing. The car wouldn't even turn over until I removed and replaced fuse 20 (no idea if this was actually related...just the last thing it did before starting to do something) It started clicking like a dead battery...I was happy to get -something-. Got a jump from a friendly passer by and it seemed fine, but I had ABS and parking brake light on the dash illumated. It ran for about 45secs after we unhooked and started stuttering and had a fuel smell which I took to be from bad spark...from low voltage. Re-jumped to verify...same.

Talked to a couple of BMW places and we agreed it was alternator failure since we seemed to lose battery power (gauges ran fine during jump, went to 0 and dimmed before engine got rough).

Got and installed a new alternator on the side of the road. (must remember to carry a pair of jeans and t-shirt in the trunk...ruined slacks and dress shirt).

Finished, jumped, started...seemed good for 3 minutes...then the same slow failure. Charged for 15min and it ran longer...same symptoms....but the battery light is now on in the dash.

Could it be a bunk new alternator? I'm thinking not, my -guess- is that I've got a bad battery as well and the old alternator might not have been bad

I'm going to have the battery replaced in the morning I guess.

It is worth noting that I replaced my AC blower fan this past weekend and while I was quite careful I wonder if it could be related? The car ran Sunday - Thursday both day and night without anything bad...but it's a data point that could be related.

Thoughts anyone?

__
Rob (Stuck in a hotel for the night)

[ryan roopnarine]

how do they die if the battery is dead? is it a solid state failure or does some mechanical part fatigue if it has to charge the battery.

[Bill R.]

how do they die if the battery is dead? is it a solid state failure or does some mechanical part fatigue if it has to charge the battery.

[TheGeak]

I had the same thing happen to me in the M5. Turned out to be a bad voltage regulator coupled with a dying battery. Replaced VR and Batt and gained a new lease on electronic life.

[Tiger]

Get the multimeter and measure the voltage... that will tell you what is the problem.