wasp

well i bought a powermaster 47861 about 6 or 7 years ago, i rarely drive the car , maybe once or twice a month in the summer, little more in the fall and spring, i have underdrive pulleys so i needed a bit more output than the stock alt, this one puts out 140 amp, until tonight.............barely made it home from dinner, i was watching the voltmeter drop and praying ,lol.............im assuming its the alt cuz battery was dead when i shut her down...........can an alternator crap out regardless of how much its used? seems i didnt use it all that much................anyways i see powermaster makes alts now with up to 200 amps , are they still top notch? and would that be too many amps?

wasp

maybe im wrong here, this alt has maybe 5000 miles on it tops, after dinner the car started but i noticed the windows were super slow and my voltmeter read about 10.................as i drove home it went down to about 8 and lights and stuff in the dash started to come on , i assume this is from not enough voltage? i made it home but the battery was dead , maybe its the voltage regulator? maybe someone can enlighten me on how to test......

wasp

well i did some reading , the regulator is in the alt so thats not an option,ive decided im going to get an optima battery and a voltmeter, with the car running if i put the + on the alt terminal and the - on the motor or body, what should my output be?................also i noticed something, i have a dual snorkel and i used the 4" aluminum duct hose, one of them had come loose and was touching the alt case, i thought maybe this grounded the alt out some way , but then i figured no , its bolted to the motor......................can someone chime in here maybe ,

iroczracer07

iTrader: (2)

Check the following in the following order:

1. The battery cable connections.
2. The wiring and connectors to the Alternator.
3. Check the drivebelt tension.
4. Make sure your Alternator bolts are tight.
5. With the engine running, listen for abnormal sounds coming from the Alternator.

The easiest way to check your Alternator is to take it off and then take it to an autoparts store for bench testing, it's usually free. If the Alternator gave up the ghost on you, Powermaster would be a good replacement, but you also might want to check out MSD's new line of Alternators, from what I've seen, they seem pretty sweet. If you're dead set on using the Voltmeter to test the system, follow the procedure below:

1. Place the black connector in the Com port and the red in the port that has the V/ohm/arrow+, sorry, I can't make the signs. Rotate the dial to the 20 mark in the DC V area.
2. Turn the ignition off if you've run the car recently.
3. Turn the headlights on for about 10 seconds to dissipate any battery surface charge.
4. Disconnect the Positive battery terminal and hook the red lead from the Voltmeter to the Positive battery terminal.
5. Connect the black lead to the Negative battery terminal. (Don't disconnect the Negative battery terminal.
6. Match the display reading against the following:

12.60 v or greater Battery is at 100%
12.45 v Battery is at 75%
12.30 v Battery is at 50%
12.15 v Battery is at 25%

This will let you know if the battery is experiencing any kind of draw. Better to be safe than sorry.

Now for the Alternator test.

1. Leave the set up the same as above, except reconnect the positive battery terminal.
2. Start the engine and let it idle.
3. Turn off all accessories and check the display reading.
13.2 - 15.2 volts means the charging system is normal.

4. If the reading is as specified above, open the throttle and hold the RPM between 1800-2800 through the next 3 steps.
5. View the reading again. It shouldn't have changed by more than 0.5 volts.
6. Now load the electrical system by turning on the lights, windshield wipers and setting the blower fan on high.
7. View the reading again. It should not have dropped below 13.0 volts.
8. shut off the accessories you turned on and return the throttle to normal and shut the car off.
9. If the voltage readings were as they're supposed to be, then the charging system is operating fine. If it failed any of the tests and you already checked the belt and so on, the Alternator needs to be replaced.

I hope that you get it figured out. Post when you do.

wasp

ok um dumb, i bought an aw sperry multimeter, the directions are kinda vauge, which is the dc area of the meter? the red v or the black v? my guess is the black? also, when checking the alt with engine idling , am i taking the readings at the battery posts? thanx for your help, it was time to upgrade the diehard weatherhandler anyway, now i hope i dont have to replace this powermaster

iroczracer07

iTrader: (2)

If it's set up like my Actron III it'll read from top to bottom 200-20-2-200m. Where did you purchase it at. If I could see what it looks like I could help out a lot more. The black lead should always go into the com port, which should be the only one marked with black around it. There should be three ports for the red lead to go into. And yes, you'll take the readings at the battery posts.

wasp

i got it , i was right , this must be a newer model , they dont have it marked dc or ac , i had to find one on ebay that was clearly marked, i bought a sperry dm-350a , instead of dcv or acv they just have black V and red V with some sort of symbols next to em, instructions are rather weak.................listen thanx for your detailed instructs.............im going to put the battery in first then try the procedure..................i dont want to buy a new alt yet until im sure its it...............i was wondering tho, for the vm to read 8 all the way home and the battery to be dead, is there any other conclusion to draw? all wires and connections are good..........would my aluminum air hose touching the alt case somehow make its output go somewhere other than the battery?

luke4907

iTrader: (5)

I'm no alternator expert, but as I understand it, there's brushes inside that actually create the electrical charge. If these brushes get worn out, then your alternator won't be able to create enough of a charge to keep your vehicle running, and you'll be running off your battery. I suppose the brushes can either get work out from too much use, or they could also get worn out or corroded from not being used as well. In any case, if all your connections at your battery and alternator are not corroded and in good condition, then it should be your alternator. Pull the sucker off and have Autozone or someone bench test it.

If the aluminum air hose were only touching the casing of the alternator, then you have no problems there. You just want to make sure the high-amp connector on the back (called B+ if I remember correctly) is not being grounded out on the engine or your air cleaner etc.

wasp

well it would be $160 for an exact replacement new from summit, think the cost of getting it rebuilt would be cheaper and worth it? sometimes its less of a hassle just to get a new one, the rebuild is only as good as the guy that did it........

iroczracer07

iTrader: (2)

Like I said, the wires to the alternator being corroded or loose could cause a problem. Also, a serious draw on the battery could have caused that problem if the alternator couldn't keep up. I've seen it happen. Better to be safe than sorry. If there is a draw, I can tell you how to trace that with your voltmeter. Let me know what you come up with.

DuronClocker

iTrader: (1)

It'd be really weird for the alternator to just up and die. When my alternator was going out on me, I would notice that under heavy load (rear window defroster), the battery voltage would drop and my lights would get real dim. I had to throw it in neutral every time I was slowing down and hold the RPMs at like 1500rpm. This went on for a few weeks gradually and consistently getting worse.

I knew it was my alternator and ended up replacing it and solved all my problems.

It shouldn't be your battery because your alternator should be able to push out enough power to run the car without a battery. Its not good for the alternator to be at 100% load all the time. This is why weak batteries can kill alternators slowly, and vice versa, weak alternators can kill batteries.

luke4907

iTrader: (5)

Not sure if Summit or Powermaster sells a rebuild kit for it (or if a generic rebuilt kit from advance or autozone would do the same job) but if you are considering a rebuild, you might as well pull out a Haynes and do it yourself. just my $.02

wasp

well iroc, i got my optima today , didnt have much time to get into it but i did test it before i put it in, 12.34....is it normal to receive batteries at %50? i put it in and hooked up negative only, still 12.34 , am i to assume i have no draw issue? or does it have to be run first?

wasp

well i hooked a charger up to it and after only 10 minutes it was 12.60, but it would slowly drop on the vm back to 12.34...............nuff playing tonight, ill get into this deeper on sat..............

iroczracer07

iTrader: (2)

Every once in a while you will get a battery that is slightly discharged. It's no big deal. Follow the procedures I listed earlier and see what happens. Drop a line when you're ready to go to the next step.

wasp

well, im glad i went the route i did, buy switching batteries and going from side mount to top mount, i had to lengthen the positive cable............well, it was melted on my header down by the starter, apparently the ja that said he moved it didnt move it far enough 3 years ago..........all test numbers were as you said they should be......one question tho, with the cable touching the header, where does the alt charge go? obviously not to the battery.........im doing things myself from now on, ive yet to find someone that does it right ................

wasp

few more questions , might as well learn as much as i can while im into this.....you say the range for a properly chargin alt is 13.2-15.2, why the range? is it because all alts are built differently and no two are going to put out the same number? mine happened to be 14.45.............is an alt that puts out 15.0 any better for the system than one putting out 13.2? also, i noticed at 2500 rpm steady throttle the number would go from 14.45 to 14.41, i figured the faster the alt is spinning the more it would put out , but the number actually goes down , is this because of the higher demand on the igniton system?

iroczracer07

iTrader: (2)

With the positive cable melted, the charge probably went wherever it could from that point. I believe the reason for the amperage difference is due to load placed on the engine. To answer your question though, no, a 15.0 amp reading is not the one you want because you're dangerously close to an overcharging situation. The reading you got is a really good reason. The reason for the amperage drop when you rev it to 2500 is probably the voltage regulator in action. Its job is to regulate the voltage to make sure it doesn't rise or drop below a certain point. Now, just so you know, I'm no alternator expert, but this is what I believe to be happening based on the small amount of knowledge I do possess. A good site to check out is probably msd or powermaster's. They should have a wealth of information to bring you up to speed and probably beyond my knowledge,lol. Glad you got her fixed though. Have fun!!

wasp

so the alt output would go thru the batt , thru the cable , then into the header, where would it go from there? does it just dissipate from there? why wouldnt it complete a circle and fry something mounted on the motor? maybe somone else has more knowledge here, but again thanx for the details iroc, really helped

wasp

just trying to understand this, the starter is connected to the motor same as the header, the cable going to starter is ok but going to header is bad...........is this because current is pulled thru the cable connected to starter only when key is turned and if its connected to header its being pulled thru constantly?

iroczracer07

iTrader: (2)

More than likely, what happened is that when the current reached the header it was probably sparking against it since the header is attached to the motor which in turn is attached to the chassis which we use to ground out the electrical systems in the vehicle. Since the power went to ground, it never returned to the battery and the battery became discharged. The charging system is a circle of parts that work together to keep current and power running. When one part of the circle is broken, every other part will be affected. In your case, the battery wire going to the starter was burnt and sending all that power to ground. This in turn more than likely forced the battery to put more juice out to start your car because the current had to be increased to reach the starter across the open wire that was burnt. The Alternator kept doing it's job by recharging the battery and allowing you run your electrical equipment, but eventually the burnt wire took its toll and probably created quite a bit of electrical feedback which was propbably reeking having on your Alternator as well as your battery. Eventually neither of them could keep up with the drain created by the burnt wire that was sending current to ground instead of to the starter. When both pieces of the charging system were so overworked they finally began saying "Hey! Something's wrong here and you need to take a look!" That's when you found the wire and said "I'm gonna kick that guy's a**!" Like I said before, there are a lot of websites which will contain more information than I have which might explain it better. I am by no means an expert, but that is what I think has happened to you in this case.