Alternator/Electrical Question

rtstrack · #1 (**permalink**) 04-12-2008, 08:08 PM

When i have a fully charged battery, the car starts right up. After I drive it around for a little bit (just a few minutes) with the fan on, the battery drains and the car won't start. So it appears that either the fan is drawing too many amps or the alternator is not charging the battery. I changed out the alternator and then the voltage regulator, and the same problem persisted. So i started looking more carefully at the parts and a black wire (i'm assuming the ground wire) coming from the alternator was threaded to a bolt (which was holding the voltage regulator in place) that was on the inner fender. So I assumed that the ground wasn't any good, sense the bolt was on the fiberglass. I spliced the wire and grounded it to the frame. When I went to turn the key on, and you hear the click, I immediately see all of the dash board lights go on and a loud weird buzzing sound. Like electrical current or something. I didn't dare try to turn it over. Any thoughts on the sound or what might be causing the battery to drain?

RICK LAKE · #2 (**permalink**) 04-13-2008, 05:28 AM

rtstrack Can you shoot a picture of this wire and show location? this would really help. As far as the rest of the car and charging system, you have lights, how many fans for cooling, any fan for heater? Are you running an electric fuel pump? Are you running an MSD ignition? Stereo? Under size pulleys on the motor? Do you have a volt meter? Fuel injection and ECU ? The first thing to do is charge the battery. Put the wires back the way they where. Make sure the connections are tight. DON'T over crush them. Get the car running and check the charging voltage. At idle should be 13.5-14.2 running at idle without any loads, motor only. If less you need to take the ALT to a pepboys or autozone and let them check the charging system. Bring the battery also, you could have a shorted cell in it. If you are running all above you need a minimum of 100 amp charging system. If you idle too long with the fans, and MSD running and only have 13.0 volts or less charging, the power is coming from the battery to keep the car running. Around 9.6 volts the party is over. Fans draw 15-20 amps each,fuel pump is 10-15 amps, MSD is 8-15 amps. With just this at idle You have maxxed out the charging system at idle. If you want to talk call me 732-254-3536. Rick L. Ps I started with a 60 amp ALT and ended with an 80 amp. The new motor will get 100 amp with 60 charging amps at idle. Check voltage at idle and 2,000 rpms, and get back to us.

Blas · #3 (**permalink**) 04-13-2008, 07:55 AM

"IF" the wiring colors on your car/alternator is similar to mine...
The BLACK wire goes to the STATOR (S) connection on the alternator, then there is a BLACK & WHITE wire which goes to the FIELD (F) connection on the alternator, and the large RED wire goes to the BATTERY (this is where all the power is supplied) And maybe a BROWN to a GROUND (G) connection too. From what you said you heard last time your turned the key on, (Where did that electrical sound originate from?) (hopefully the alternator?)
I would isolate the alternator from the car (remove all the wires) (CAREFULL - THE RED WIRE IS ALWAYS HOT) and quickly turn the key on, and see if the sound is gone? You may have toasted the alternator (and/or voltage regulator) with the wrong wiring arrangement earlier, have it tested.
I'm assuming all connections to the battery & chassis grounds are good too...
Your initial problem sounds like a bad cell in the battery to me...

Maurice Johnson · #4 (**permalink**) 04-13-2008, 08:57 AM

When sorting out grounding problems, one piece of info that is rarely emphasised is that the ground wire on a DC system should be at least the same size as the red supply cable from the battery, and continuous back to the battery. Unlike AC current, DC comes out of the battery, does the job its asked to do, and goes back to the battery. That is why shunts are installed in the return cable for battery condition indicators.Resistance is the reluctance of the electons to flow through an inadequately sized wiring harness to do their job. (think of water in a kinked hose--same thing) The alternator is part of this resupply equation. When getting into high output alternators, the mounting bolt is often times not an adequate ground. Stainless steel in NOT a good conducter of electricityy--dont use stainless on electrical connections. Any alternator that was designed to work with high output windings will usually have a 1/4" 0r 5/16" stud ,or a cap screw marked for negative, at the back of the body (unless it is an isolated ground alternator,thats a whole different story which does not apply here). This is where your main negative should originate, and maybe go to a heavy bussbar which has an insulated base. BlueSea make a neat 100 amp unit. All you other negatives can go to this bar, which is in the line back to the battery. Rinky-dink little pieces of 14,16,18g wire connecting components together do not contribute to a good system. Neither does trying to get a good ground on a powder-coat surface.
What I am spouting here is basic DC electrical theory.As they say on TV, check with your doctor before consuming.

Blas · #5 (**permalink**) 04-14-2008, 05:50 PM

So? Whats's the verdict?
Has the problem been Resolved?

rtstrack · #6 (**permalink**) 04-16-2008, 05:03 PM

Ok I fixed the noise problem. Apparently the black wire wasn't grounding the alternator through the voltage regulators bolt, but it was actually the voltage regulator that was being grounded through the alternator. Anyways its back up and running but with the engine at idle the battery only tests at 12.0. An additional piece of info is that the voltage gauge (on the dashboard) reads slightly less then 12 when it starts up. When i turn on the fan & lights it will drop down to 10.0, but then when i turn them off the needle immediately bounces back up to 12. So I'm assuming that the alternator IS working, because if it wasn't, then wouldn't the needle stay at 10.0 and not return back up? I am now assuming that I have an undersized alternator. I swapped out the alternator with the EXACT same one that was in the car (got it from NAPA), it was just some generic ford alternator. The sticker on the side of the alternator reads 34amps @ 2,000 rpms and 72 amps @ 7,000 rpms, these are aproximately the numbers I remember seeing before I installed it, give or take an amp or two. Rick, I have lights, fans, msd, stereo. No idea if the pulley is undersized or not. Not fuel injected. Hope this helps

CHANMADD · #7 (**permalink**) 04-16-2008, 05:09 PM

Disconnect the NEGATIVE while the car is running,and it should continue to run if the alternator is charging.If it is not charging the motor will die the moment you disconnect the negative cable.

Rwillia4 · #8 (**permalink**) 04-16-2008, 05:09 PM

Get a multimeter and test the voltage at the battery terminals. It sounds like the circuit that your gauge is on has other componets on it which is drawing down the voltage on that line. However this is not the voltage that the battery is seeing from the alternator (hopefully). To fix this problem change the power wire of the voltage gauge to a different circuit.

rtstrack · #9 (**permalink**) 04-16-2008, 05:26 PM

I read somewhere that if you disconnect the negative while the car is running it will send a spike of electricty back through the car and fry some parts (maybe my MSD)?

Joe Wicked · #10 (**permalink**) 04-16-2008, 07:49 PM

Quote:

Originally Posted by rtstrack

I read somewhere that if you disconnect the negative while the car is running it will send a spike of electricty back through the car and fry some parts (maybe my MSD)?

Not exactly true, if something is not grounded properly, it can affect it, but not by sending a spike of electricity. This is more of a problem on cars that use the on board computer to monitor and control everything. When the battery is pulled from the system, the computer tries to compensate throwing the voltages off, thereby the "voltage spike" that is not really a spike.

Quote:

Originally Posted by Rwillia4

Get a multimeter and test the voltage at the battery terminals. It sounds like the circuit that your gauge is on has other componets on it which is drawing down the voltage on that line. However this is not the voltage that the battery is seeing from the alternator (hopefully). To fix this problem change the power wire of the voltage gauge to a different circuit.

Very good check to do before you pull the battery. If you are seeing good charging voltage here, but not at your gauge, verify that the reading at the gauge is the same with a multimeter. Simple thing that gets overlooked and causes needless troubleshooting. Never assume 1 instrument is correct. verify it.

A simple check to do as well is to pull a battery out of another car and swap it. If it goes away, you know you have a bad cell. A bad battery will load down a system and cause other components to fail. An example is on my Mustang the battery light started to intermittently come on, I had the 515 cold cranking amps battery tested and it was only 345. I changed it out and the light went away for about 2 weeks. It has now come back on 1 time for just a moment. When I check voltages, they are not stable. It looks like that the voltage regulator was working excessively to compensate for the additional load from the battery. This caused the voltage regulator to prematurely fail. It is not to the point of leaving me stranded, but it will go bad before too much longer. I have to verify the alternator is charging properly, but I am confident that it is.

If the charging voltage is good at the battery but not at the gauge, start troubleshooting by disconnecting items. Disconnect the stereo and start the car. If that is not it, pick another item until you find it.

Hope this helps.

rtstrack · #11 (**permalink**) 04-20-2008, 06:19 AM

I thought my alternator issues were resolved, but they aren't. Could anyone assist me in determining how my car should be properly wired? The parts I am dealing with are battery, solenoid, msd box, external voltage regulator, 1g alternator and a distributor/unilite ignition system, coil. The car starts fine, so it seems my starter/ ignition system is wired propery, but my alternator is not charging my battery. Upon further inspection of my wiring harness I think I found out why, the STA wire on my alternator was litterally going NO PLACE. Here is how my car appears to be wired. MSD box - one red wire going to + solenoid, two wires going to distributor/unilite ignition system, two wires going to coil. External voltage regulator - I, A & S wires go somewhere into my fuse box ( the box is on the inside shelf and I can't see exactly or get to it), the F goes to the F on the alternator. Alternator - BAT has big red wire going someplace into fuse box area, F goes to regulator, ground - three wires - one from unilite, one from regulator and the third grounds those 2 and alternator to frame, the STA goes nowhere. So this is what I have so far, any ideas? The wire that was hooked to the STA had a S taped onto it so I tried taking the other end and putting it into the S slot of the regulator and taking the S wire (that was there, and that comes from the fuse box) out (just left it hanging) but that didn't work either. No matter what combonation I try the dash gauge never goes beyone 12 volts and the battery never reads over 12.5 when idle or otherwise. The manager at napa said to try putting a wire from the + of the coil to the F on the alternator and see if that works..apparently he thought the ignition wasn't signaling to the alternator to "start" and this hard line would take care of that....it didn't. The voltage was reading 5volts at the BAT terminal on the alternator and 13/13.5 volts on the F of the alternator. From what I've read everything seems to be reading correctly. Oh...and I brought the altnernator back to NAPA to have it tested just to be safe..and its fine. Whats throwing me off is that the wire from the BAT and the wires from the S, A & I are all leading off to some type of junction box that I can't completely see or get too. At this point I think I'll try disconecting all of those and try the simple diagram wiring. Send the BAT straight to the battery and take the F & S and send them from the regulator to the alternator and send the A to the BAT field and leave the I alone. I'm open to ANY suggestions at this point. When I start her up the lights are off, the fans are off (seperate relay) and the stereo has its own set of cables for the battery (which i've been leaving off so that I don't over load the alternator at this point) so it seems as though I shouldn't be overloading the alternator. I'm open to ANY suggestions at this point.

rtstrack · #12 (**permalink**) 04-20-2008, 06:20 AM

Oh and I tried disconnecting the neg terminal while the car was running in each different scenario the car died immediately...

Joe Wicked · #13 (**permalink**) 04-20-2008, 09:02 AM

Just a quick question, Has the car ever worked properly? Was it working and then stopped, or has it always been this way?

It definitely sounds like you have a charging problem. The battery is providing all electrical power. Without looking at the car, I would have to guess that there are bad connections somewhere. Starting over with the charging system may not be a bad idea. If you can find someone local to you that is familiar with electrical troubleshooting, he may be able to help by looking at the car as well.

Ron61 · #14 (**permalink**) 04-20-2008, 09:30 AM

Since we can't see your wiring, I can only guess. But the voltage at the battery or on your voltmeter should read from 13 to 14 1/2 volts with the car running. I had a voltmeter in my dash which I like as I could just glance at it and see if the alternator was charging the battery.
As Joe asked, has it ever worked properly, and if so did you make any changes at all before this started?

Ron

rtstrack · #15 (**permalink**) 04-20-2008, 09:56 AM

When it was picked up by my transporter they had to jump it, and then again when they delivered it to my house. So I am going under the assumption that it was not working properly when I purchased it. I'm going to try re-wiring, but i'll keep all of the original wiring in place just in case I need to bring it to a pro. Thanks for all of your help

Maurice Johnson · #16 (**permalink**) 04-20-2008, 11:24 AM

2 books which turn darkness into daylight are "the 12 volt doctor's practical handbook", ISBN # 0-911551-07-7, and "the 12 volt doctor's alternator handbook", ISBN # 1-878797-02-6, by Edgar J Beyn. Even though some of the references are to marine matters, the electrons don't know that, and still do the same job. I have no commercial interest in these books, just know they are priceless for these generally older technologies. To Quote Carl Malden, don't leave home without them.

Blas · #17 (**permalink**) 04-20-2008, 01:37 PM

You'll have an personal message in a moment....

Joe Wicked · #18 (**permalink**) 04-21-2008, 04:57 AM

Sounds like it was never wired right. Where are you located? I am sure someone local to you would be willing to help you out.

acmjg · #19 (**permalink**) 04-21-2008, 06:59 AM

Good reading at the sites below.
Good luck!
Anthony

http://www.rowand.net/Shop/Tech/Alte...atorTheory.htm

http://www.erareplicas.com/427man/wiring/alt.htm

http://www.madelectrical.com/index.shtml

http://www.midnightdsigns.com/james/...g%20Gauges.htm

rtstrack · #20 (**permalink**) 04-23-2008, 07:35 PM

IT'S ALIVE....IT'S ALIVE...after numerous hours of tinkering and replacing several wires/parts she was reading 13.8ish/14.0 even with the fans and lights on. Not sure what it ended up being but I think it was one of three choices #1 I replaced the voltage regulator (even though I had just replaced it 3 weeks ago), couldn't be sure if I fried it mish mashing wires. It was a cheap swap out. #2 I have looped battery cable ends so I was using a connector on the top posts. I switched to the side posts after I noticed that whenever i brought it to advanced auto to charge/check the battery it would always come up as BAD when i had the connectors on and GOOD when it was directly connected to the posts. So I assumed that if the machine was having a hard time reading through the connectors maybe a charge wasn't getting back to the battery #3 I already had a wire running from the BAT of the alternator to my fuse panel and in turn a wire was running from the fuse panel into the solenoid (and then on to the battery), but I also ran a direct wire from BAT to the solenoid (bypassing the fuse pannel). So I really want to send out a big THANK YOU TO EVERYONE for getting me up and running

Regards
Ryan