[mitch968]

I think I may have a dead alternator, or hopefully just need a new regulator. Driving home last night, I noticed the voltage was about 11 on the gauge, and normally it is above 13 and dips down to slightly over 12. Of course, these readings are a bit lower than actual voltage at the battery. It was raining heavily last night, so I was hoping it was just the gauge flaking out due to bad grounds, etc.



I began my troubleshooting this morning. The actual voltage at the battery is 12.2 with the car off. With the car idling, the voltage goes down to around 11.7 with no lights or other accessories on, so clearly it's not charging. Raising the RPM's doesn't seem to make a difference. The belt is still on there and spinning the alternator just fine.



Some questions for the experts out there.... How likely is it that the alternator is ok and just needs a new regulator? I know the regulator is a wear item, but could it fail suddenly like this? Is it more likely that the alternator itself is blown? Can an alternator die suddenly on its own, or would it more likely be caused by something like a short? I'm currently running without the engine undertrays while I hunt down a PS leak, so I'm hoping water didn't splash up there and screw something up. Any other troubleshooting steps or ideas?

Partial Post: Please Login or Register to read the full post.

[bob blackwell]

Sounds as if you need to take it off and have it checked at a rebuild shop. TNT Electrics here in Albuquerque rebuilds them for $75 and they will tell you if it just need a regulater. I run with my lower engine covers off all the time with no problems - of course, it does not rain much out here in the "high desert". Good luck, Bob Blackwell.

Partial Post: Please Login or Register to read the full post.

[flash]

sounds like a regulator, but you can do a quick test on the alternator yoruself - remove the belt and spin it by hand - it should be smooth with a slight resistance, but not one you can feel in anything but the wrist twist - if it makes any noise or spins too freely, you probably need a new one



however, the regulator is cheap and easy to replace, and i would change that out first anyway - they are well know for wearing out, usually by 100k



running without the engine covers will only hurt you in that it is less effective at removing the hot air from the engine bay, increases your drag coefficient, and increases underhood air pressures - it'll rob you of some top speed stability and maybe a touch of gas mileage, but it really should not play into this particular problem

Partial Post: Please Login or Register to read the full post.

[astrojeff]

I just changed my alternator this past weekend. Was a bit tedious, but not too difficult. A rebuilt alternator (rebuilt in Germany by Bosch) is only $160-180 and comes with the regulator, so I figured it was better to do the whole thing. A lot more work though. Pelican has them in stock with free shipping.



Jeff

Partial Post: Please Login or Register to read the full post.

[mitch968]

Thanks for the info. I've got a regulator coming from Paragon....should be here tomorrow. I got the cheaper aftermarket one, so I'm not out much should it not solve the problem. If that doesn't work, I guess I'll shell out for the alternator. I almost forgot that Pelican has the free shipping.....good idea since it's a heavy part.



Jeff, what was tedious about the swap? I thought it was just disconnect battery, loosen the tensioner, remove 2 bolts, and disconnect wires, and reverse for the install. Are there any particular "gotchas" I should watch for or is it just difficult due to tight spaces? How long would it take a relative novice like myself?



I plan to swap the regulator with the alternator in place, and only yank it if it doesn't solve my issue.

Partial Post: Please Login or Register to read the full post.

[flash]

alternator install note - important - adjust the belt tension with the mounting bolts just cracked loose - in other words, no preload on the bolts - then tighten mounting bolts when done - failure to do this far too frequently results in broken mounts

Partial Post: Please Login or Register to read the full post.

[mitch968]

I ended up getting a reman alternator from Sunset and went to do the swap today. I got the old one out and need to remove the pulley from the old alternator to put on the new one. I can't for the life of me get the 24mm bolt loose to remove the pulley. It's tough because the shaft needs to be held still while just turning the bolt. I've tried sliding a few long screwdrivers through the metal fan assembly to hold it in place, but can't seem to get enough torque. I'm trying to be careful to avoid nicking the pulley at all which could cause belt damage. Is there some special tool or trick to get this removed? Already tried some liquid wrench and I'm letting it soak a bit longer now, while I try to figure this out.



Any tips would be greatly appreciated. Thanks.

Partial Post: Please Login or Register to read the full post.

[flash]

impact gun - if you don't have one, can you go to a tire shop and have them pop it off?

Partial Post: Please Login or Register to read the full post.

[mitch968]

Yup, after some searching I realized that and unfortunately I don't have one. I found a local parts store that swapped it for me no charge this morning. There is also a little metal key that holds the fan in position....we had to pry that out and put it on the new shaft.



The parts guy was commenting that many reman alternators come with the pulley included. Then I mentioned it was a Porsche part and he understoood why it wasn't included. ;-)



The old alternator wasn't incredibly noisy, but the new alternator spins nice and quiet. I'll be popping it back in before work tomorrow, so hopefully my charging woes are behind me for the foreseeable future.

Partial Post: Please Login or Register to read the full post.

[mitch968]

Arghhh!



So, I managed to get the pulley swapped at a local parts store for free and I installed the alternator first thing this morning. I ran it in the driveway for about 10 minutes while I cleaned up and everything was running great and charging at around 13.5 volts (though I thought it should maybe be a bit higher than that?). I had topped off the battery with a charger a couple days ago, so as not to overwork the new alternator.



Unfortunately, while driving to work a few miles from my house the voltmeter spikes and I start swearing. I pulled over into a nearby parking lot and whipped out my multimeter to verify and sure enough I was seeing over 17 volts at the battery! I shut it down and called my wife to pick me up.



Now I've gotta figure out whether this is an easy fix or if I should just have it towed to my guy. In theory, I suppose I could just disconnect the alternator and drive it on battery for a short distance.



Anyway, my first thought is that the voltage regulator died. I actually have a new aftermarket regulator that was purchased recently for troubleshooting, however I don't want to put that in if it's just gonna blow in a few minutes. It seems to me that something is causing my alternator problems, since the old one just died and now my new one's regulator appears dead. How likely is it that the VR on the new alternator was simply faulty? Could it be something else? BTW, my alternator/starter harness was replaced a while ago, so it's in great condition.



I'm running out of ideas and patience. Any ideas before I throw in the towel and just bring it to my mechanic? If it comes down to it, I'm really not looking foward to yanking the alternator again.

Partial Post: Please Login or Register to read the full post.

[Bob Kovacs]

It's very possible that the voltage regulator in the new alternator died. Stuff like that happens with electronics all the time. I'd give your spare regulator a shot before turning it over to a mechanic. There's a very good chance the new regulator will fix the problem.



--Bob

Partial Post: Please Login or Register to read the full post.

[mitch968]

I suppose it's possible, though I would have hoped that when Bosch remanufactured it, they would have tested the thing. Do you know if they are supposed to replace the regulator as part of a remanufacture?



I suppose I have nothing to lose. Worst that could happen is I blow out another one. I've still got my old Bosch regulator (probably ok) and my new aftermarket one, plus it would seem that Sunset owes me another now.



I did reuse the condenser(capacitor) from the old one. Is it possible that's causing a problem when it heats up? Maybe I should remove it?

Partial Post: Please Login or Register to read the full post.

[Bob Kovacs]

A problem with something right out of the box is always nerve-wracking. It could be the condenser, or it just may be that the regulator had early infant mortality. Such things happen. If it was my car, I'd try the new regulator and keep an eye on it. If it blows (or if the voltage goes high again), then there is an odder problem.



Chances are that you are the victim of infant mortality.



--Bob

Partial Post: Please Login or Register to read the full post.

[mitch968]

Crap....just nearly sweated to death trying both my original regulator and the aftermarket new one. Both resulted in overvoltage right away. Technically, neither is really known to be good, since they were both on my old alternator which could have blown them. The more I think about it, I would think that if either was ok, it would at least last a few minutes before blowing like the other one did unless there's a problem with the alternator itself at this point.



I'd hate to bring it to my mechanic just to swap a regulator, but I'm a bit hesitant to keep throwing parts at it and I can't really take having it off the road for so long. If I'm not going to save money, there's really no point in doing it myself. Sunset is telling me I'd have to return the whole alternator to do an exchange, not just the regulator....that would make it more trouble than it's worth. Really frustrating when a relatively simple job becomes a pain in the ass fiasco.



Maybe I should start a forum poll...who votes I try out a new regulator? who votes I throw myself at the mercy of my mechanic so it becomes his problem?



Bob, I'd love to have your optimism, but at this point my love/hate relationship with the car is tipping toward the hate side. Do you still think it's just a bad regulator?



Bonus: I finally tripped my airbag light with all of the battery connecting/disconnecting. Fantastic.

Partial Post: Please Login or Register to read the full post.

[flash]

i presume you are testing voltage with a known functioning meter, and not the one on the dash



there is a known meter failure condition that has nothing to do with whether or not the alternator is outputting correct voltage



lol - once again, this is a thing that has happened to ron

Partial Post: Please Login or Register to read the full post.

[mitch968]

Yup, I have a multimeter that's accurate (and quickly becoming a permanent fixture in my car!) A gauge problem was actually my first thought, but I measured over 17 volts at the battery right after pulling over. When not running but with the ignition on, the dash gauge still reads about 12 volts, which is as accurate as it's always been (about .5 volt low).



I'm sure Ron wasn't LOL at the time ;-)



I'm leaving the car where it is overnight, so I can cool off physically and emotionally. Unless I can figure something out by tomorrow morning, I'll probably call my mechanic when he opens and have it towed there (free with my insurance, so might as well use it.) If it turns out just to be a regulator after all, it would just be a bit more $ getting it through him, and if it's something else it will be in good hands. Speaking of towing, how quickly would I toast the battery or worse if I drive it as it is now? Alternately, is there a proper/easy way to disconnect the alternator to just drive on the the battery a short distance? I traced the positive alternator lead and disconnected it from the positive battery terminal and it started and ran ok, but I got nervous because the gauges didn't work at all with it disconnected. I ended up reattaching and no harm done, but maybe that's what tripped my airbag light.



On the positive side, I'm getting good at swapping voltage regulators. I've been very careful because the car is in a gravel parking lot and if I drop a screw it's pretty much lost. I've been putting a tarp under the car just in case I drop something, but so far I haven't dropped a single screw.

Partial Post: Please Login or Register to read the full post.

[BigL2U]

This may be a dumb question but have you checked your grounds?? I'm currently showing my car some love and it was suggested that I check for loose screws and bolts.



Well I found two ground points that were lose. One was reading 2K ohms difference from the chassis. A little electrical grease and a couple of turns later its now reading about 1 ohm.



Just a thought.

Partial Post: Please Login or Register to read the full post.

[mitch968]

I checked most of the grounds about a year ago and they seemed ok. I did not get to the one way back on the bellhousing though. At this point, I'm going to hand it off to my shop and return the non-functioning alternator for a refund. I would like to solve this myself, but I just don't have the time right now. It's my daily driver and I'm getting tired of riding the motorcycle, since we've been having a lot of rain lately.

Partial Post: Please Login or Register to read the full post.

[flash]

that sucks - there does seem to be a problem with the circuit somewhere - could be a short in the field - might have just gotten a bad unit



in the meantime - be careful - shiny side up

Partial Post: Please Login or Register to read the full post.

[mitch968]

My shop replaced the alternator for me yesterday and so far so good - charging around 13.5 volts. I could have just done this again myself, but didn't want to get into spiraling shipping costs back and forth if it turned out to be more than a faulty alternator. Their price was quite reasonable anyway, and I'll just go ahead and return the faulty alternator for a refund now. I'm still not quite believing it was that simple, but I'll start to come around after a few weeks of problem free driving.



Two related questions:



1. What kind of voltage should I be seeing on a healthy battery at rest? For example, the morning after a longish drive before starting the car. This morning it was down under 12.4v which seems a bit weak. I could swear my motorcycle battery gives a reading closer to 12.8v (haven't measured in a while). I drove to lunch today and after an hour break it was reading just a hair under 12.5v at rest.



2. What's the best high quality reasonably priced battery out there for our cars? I would want something designed to fit and am not interested in modifying wiring or anything else. I'm thinking my Autozone Duralast is a piece of garbage and I shouldn't subject the car to it much longer. It's about 1.5years old and was a free replacement for another Duralast that lasted only 2 years. (The first one may have died early due to an electrical issue that has since been fixed.)

Partial Post: Please Login or Register to read the full post.