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View Full Version : I am ashamed of myself -- bad job fixing simple problem



TCarlisle
05-28-2009, 10:44 AM
Ok, so I am a pretty experienced dude. All the mods in my list were done with my own hands. Going back 20 years, I have rebuilt engines, transmissions, and done all the standard maintenance tasks for at least 20 years. Also, for 20 years I have been mod'ing cars with audio systems, and of course doing that also makes a person an electrical system expert.

Well, all that experience is chucked out the window as I am a certified dumb ass after what I did the past week.

Last friday, I drove home from work and then went to a restaurant to get a burger. Actually, I drove through the car wash first. When I got to the restaurant, I saw that the car wash didn't wipe off or rinse off the stuff they use to clean the wheels, and it left a haze on the wheels and looked like it was eating the paint! So I got back in the car to go to the car wash and get that taken care of. The car wouldn't start. Starter turned real slow and there was no way the starter was going to start the car.

So I looked at the battery and found that the cable was loose on the positive terminal. I was around the corner from my house, so I removed the battery, took it home and charged it for about two hours at 10A and took it back and re-installed and it started the car.

Ok, so at this point, I am thinking -- battery terminal came loose, affecting the ability of the alt to charge the battery, no big deal.

I put a mulimeter on the battery as the car is running and see the voltage in the low 12's. It seems the alt isn't doing a very good job charging.

Now I am thinking, well maybe the alt blew because of the battery terminal coming loose and causing spikes? Or the battery really isn't fully charged, but just quick charged. So I decide to put the battery on the charger overnight.

The next morning, I re-test and of course with a fully charged battery, as the car is running I am seeing voltage in the 13's. But as I turn on accessories, I see the voltage go down, and down, and down. Crap. It is starting to look like an alternator problem.

The alternator is just a year old. Crud. I removed the alternator to look at the voltage regulator, brushes, and visually inspect and "sniff test" the diodes. Nothing appears to be wrong. But I can't bench test the alt and the shop that could do that is closed and I wouldn't have transportation anyways. Note to self -- when I get this working, change the belt as it is really cracked and worn.

I put her back together and retest, and of course the voltage just keeps dropping. I run the car with the AC and headlights, etc for a long time and it pulls the voltage down and kills the battery and then the car doesn't start. Charged the battery again. As I was doing this test, I did rev the engine to about 2500rpm, and it was raining with high humidity, and I heard some belt squeal. I visually inspected and couldn't see the belt slipping and it was definately turning the alternor. Note to self again -- deal with that belt once this is sorted out.

So I order a new remanufactured alt and paid for next day shipping to the tune of about $350. I had errands to run that day so I had to drive the car. I was able to drive without AC or headlights and before I shut off the car I tested voltage and it was 13.3. So I knew I could shut off teh car and expect it to start again.

As I waited for the new alt to come in, I noticed I could drive without a load on the electrical system, and all was fine. But as soon as any loads were put on the system, it crapped out.

So the new alt came in, and I swapped it, and upon testing I find the same damn thing.

Now I am thinking maybe the battery was toasted as a reuslt of all of this? So I go buy a battery. I had an Optima yellow top, but I bought a parts store brand as this was getting expensive.

So now it is a weekday, so I put the old alternator in the trunk and drive to the alternator shop that can bench test the alternator and do an "in car" alt check. Well, the "in car" alt check was exactly what I had been doing, and the assessment of the shop was that it appeared the alt was not putting out, or something in the car was drawing. They bench tested the alt I had removed, and it tested fine. The guy said the new alt was probably fine too, and that the problem was elsewhere in the car.

So now I am stumped. In 20 years of experience, and a lot of experience with electrical systems, and actually kind of scared. What the hell could be loading down the system this much? I bypassed my audio system completely to rule that out -- it wasn't just turned off but was physically disconnected to rule it out. It turns hot and now I am no longer seeing voltaghe in the 13's, even with all accesories off. Is this car eating alternators? I am very scared now, because swapping alternators tryting to find out why the car is eating them would cost thousands.

I get out the Bentley and start pulling fuses of all the accesories that likely would draw a load. Nothing helps. All seems fine.

The next morning (today) I get up and test again, and the alt is putting out 13.3V with no accesories on. That is a good thing, as I didn't see 13's since it got hot yesterday.....

Also, I had noticed for the past month or so an issue with the AC. The blower goes down to low intermittently. I just figured that is a minor issue. Now I am thinking maybe the AC issue is loading the system?

I also noticed that when I shut down the car and put a battery charger on it, the battery charger indicates the battery is quite dead. But, if I disconnhect the car from the battery, the battery charger doesn't indicate dead battery. More evidence that something is seriously wrong with the car electronics.

Well, I gave up. I just was out of ideas. As I test and test, that belt is squeaking, so I figure I will just take a break form it, think about it for a few hours, and take some time to deal with that belt.

Installed belt, tested electrical system, checks fine. 14.2V at ilde and stays in the 13's with the electrical system loaded with accessories.

So charging system troubleshooting 101 is to check the belt. I knew that. Hell, I have done that to fix problems in the past on older cars. This problem was fixed in 20 minutes and $20 by changing the belt. But I spent $450 on an alternator and battery which wasn't needed.

So here is what I learned, besides change the damn belt.

1) There are things that continue to run after the car is shut off. We all hear that little blower motor sound. This creates a draw on the battery and is probably why my battery charger indicated a dead battery - because the charger was supplying power not just to charge the battery but to also supply this draw -- which is normal.

2) Having done the fan delete mod, my AUX fan comes on more frequently than a stock car. This is normal, and is why I was not seeing good voltage even when accessories were turned off once the ambient temperatiure raised and after I had been running the engine to test -- my aux fan was on and was creating the load that pushed my "unhealthy" charging system over the edge.

Meatball546
05-28-2009, 11:04 AM
That's quite a novel you wrote ;) . Anyway, glad to hear you get it figured out.

ducky328i
05-28-2009, 11:13 AM
have you tried changing your belt?
















































:shifty

Im Over It
05-28-2009, 11:23 AM
It seems sqeaking fan belts a the cause of a lot of problems in BMWs.
Good read too.

TCarlisle
05-28-2009, 11:52 AM
Well, my afterthought is this.....

1) sometimes we let our experience level get in the way. Years back, I remember dealing with this type of issue and the first thing was to change the belt. With the belt only being a year or two at most old, and not seeing any slippage, I ruled it out.

2) Sometimes we let the complexity of the modern European vehicle get in the way. Years back, we had an alternator, a belt, and a battery and the only thinhg drawing on the system was the ignition coil and headlights and a radio that put out 5W per channel. Today, we have computers -- engine computers, transmission computers, central locking, EWS, and the list goes on. We have an electric fuel pump. Everything in the interior is lighted or motorized. But with all that complexity, it still boils down the basics -- alternator/belt/battery. If I had applied "old school" thought to this problem and ignored the complexity of the electrical system, I woudl have changed the belt and been done with it.

ducky328i
05-28-2009, 11:57 AM
my personal thought process is to start with the cheapest thing, and work my way up lol

328 Power 04
05-28-2009, 12:08 PM
my personal thought process is to start with the cheapest thing, and work my way up lol

yea, funny cuz usually it is the cheapest thing.. to the OP, glad you found out your problem!

EThirtySicks
05-28-2009, 12:13 PM
my personal thought process is to start with the cheapest thing, and work my way up lol
The thing is, this is usually a great idea, too :rofl


The simplest solution is usually the best.

TCarlisle
05-28-2009, 01:31 PM
Yesp. Start with the cheapest and easiest and most likely cause of the problem. A $20 belt. LOL. I overthought the process.

I am wondering if I had the right belt on the vehicle to start with. One of my audio amps has a digital voltmeter readout, which is nice because I can see the health of the electrical system just by looking at the display. I can't recall seeing 14.2 volts on that display, or even 13V, in a long, long time. In fact, that is one of the reasons I replaced the battery and alt a year ago. The alt was over 200K miles old, battery was 4 years old, so I changed both proactively. I was suprised after changing both to see the readout on that amp still in the 12's.

But I blew it off figuring it must be normal for my setup. Went problem free until last week.

But I can't recall getting a very good voltage readout really ever. That amplifier is a recent addition, within the past couple years, so I never had easy access to my voltage readout before adding that amp, and before I saw the readout on that amp I never checked or worried about the health of the system.

But prior to adding that amp, and thus getting a voltmeter in the process, I had done the UCC pulleys, which came with a belt. I am not sure how long ago that was, but probably 2 years. Maybe that belt was not right, or maybe it wore out quickly and was already worn when I installed that amp (which would have been a very quick failure for a belt).

Well, I am running the Dayco belt part# 5060630 for a 2000 Dodge Intrepid 2.7L and getting a nice 14.2 readout.

Bimjam96
05-28-2009, 01:34 PM
word, i thought my tranny was in desperate need of a 2500 dollar rebuild. turns out it was a $30 front motor mount.

edbd1
05-28-2009, 01:45 PM
Funny. Every time you mentioned hearing the belt squeeling, I kept thinking you need to replace it first, then check voltages. I had a mk2 Jetta that would throw water on the belts when it rained. It was missing a cover that protected the belts and pulleys. Whenever this happened the belts would start squeeling and lights would dim until they dried off and stopped slipping.

ublemaschine
05-28-2009, 11:47 PM
my personal thought process is to start with the cheapest thing, and work my way up lol

+1

If you get to the point in diagnosis where you have to throw parts at it, always go with the cheapest/easiest thing to install. I've learned that from experience, lol.

TCarlisle
05-29-2009, 11:20 AM
Funny. Every time you mentioned hearing the belt squeeling, I kept thinking you need to replace it first, then check voltages. I had a mk2 Jetta that would throw water on the belts when it rained. It was missing a cover that protected the belts and pulleys. Whenever this happened the belts would start squeeling and lights would dim until they dried off and stopped slipping.

Yes, when I wrote it I mention the belt a few times so the keen reader and enthusiast can laugh as they continue to read.

Although it sucks to have bought a few parts I didn't need, it isn't that bad since I plan on never getting rid of the car I will put the parts in storage and will use them eventually someday.

I have an old set of catalytic converters under my porch, so I guess I can store an alternator too.

Mickey Knox
05-29-2009, 04:38 PM
dont feel bad, friends of mine (also quiet experienced gearheads), tried to trouble shoot a dirt bike that wouldnt start, so they started tearing into the thing, took of manifolds, panels, seat etc. until after about 2 hours somebody picked up the tank to move it out of the way and noticed it was empty :D

that was almost 10 years ago, and they are still hearing about it.