03 gt Charging problem

03GTboi

New Member
Nov 2, 2010
19
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0
London, KY
Hey everyone im new to stangnet and need a little help.

I installed a couple of subwoofers (JL audio) in my 03 mustang GT today. everything went fine until i went to connect the hot wire to the battery. Well the battery cable connector was coroded up (i just got the car a week and a half ago). After taking a wire brush to it i find the bolt that went through it the head was rounded off. Well after trying a smaller socket, then vice grips to no avail i had to cut off the terminal. well i went and got a new one. Hooked it all up started the car. Adjusted the settings on my amp, got everything sounding good. So i go in the house. A little later after the sun set i start to head out the road. After about a mile i notice my voltage is dropping quick. I barely made it home. I checked all my wiring. Everything is wired just like it was before just a new terminal (both wires that were hooked before are securely hooked now. I checked the fuse box under the hood everything was fine. I checked a wiring diagram and i see several in line fuses/fusable links and stuff, could i possibly have blown one of these? Someone suggested this. If so where would it be located? It starts and runs fine until the battery goes dead. I work from 10:30am til 9pm everyday til sturday so ill try to work on it more saturday. Any suggestions will be greatly appreciated.

03 Mustang GT 5Spd. other than the audio system and the flowmaster exhaust it is completely stock.
 
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The white fusible links are installed inline between the battey junction box and the Main alternator B+.

Are you positive that the battery terminals are corrosion free, clean, and tight? Corrosion can migrate up the cables. What about the grounds around the battery and radiator core support?

Measure the voltage at the battery positive and then at alternator B+. Next measure the voltage at the alternator YE/WH wire. Be sure to use the battery negative as ground. Post the results.

Check fuse F1.20 and F2.5.

Check the two small wires connected to the alternator. Are they clean and tight?

Take to an autoparts store and have the alternator tested for output and excessive AC ripple.
 
It was charging fine until i changed the terminal. What i figured was that when i put the new terminal on i saw it arc. I figured that it had burnt one of the fusible links or blown a fuse when it arc'd.

I couldnt find my mutimeter. Ill pick up a new multimeter and test it but that wont be until this weekend.

The wires to the altenator are clean and tight.

Thanks for all the help in advance.
 
Im taking some vacation time in the morning before work and im gonna charge the battery tonight real good and drive it to the autoparts place in the morning and have it tested. Rule that much out first then if its a wire/fuse issue ill cross that bridge and buy another multimeter and test all that.

Ill post the results of that. It doesnt make sense that it would be my altenator. If so it would have to be a strange coincidence that it just messed up at the point that i had to replace the battery terminal. I love subwoofers but dang if i had known itd be this much hassle i think i woulda left well enough alone.

Thanks alot wmburns
 
OK let me make it clear that this is the first ford ive ever owned, so never dealt with the fusible links before. I actually had mistaken a connector near the fusible link as being the fusible link. However looking in the manual i found the black and orange wire to the 2 grey wires coming out of the fuse box fusible link. I checked wires on both sides of the link and its hot on both sides so i would guess that would rule out the idea of the fusible link being bad? :mad:

Both wires going into the altenator are testing hot. Should one of them be ground when its activating the altenator to charge?

If im correct about the fusible link, and all the fuses are good which i have checked then it would appear my altenator is either bad or its wiring one.

I really hope im wrong lol, my wife just bought me the car as an anniversary gift like 2 weeks ago. if i have to replace the altenator already shes gonna freak... lol anybody got a tranqualizer dart i can borrow just in case...

I should know in the morning and will post results...
 
If the battery terminals are not clean, corrosion free, and tight, this could be the source of the problem.

If the key is turned to "run" (do not start), does the dash battery light come on? Did you CHECK the fuses?

What is the voltage at the battery?

The Mustang GT's alternator is stupid easy to change. If $$ is tight, get a salvage yard alternator. Should be around $50.

Try car-part.com or Yellow pages.

It does seem like the alternator is fried. However, there should also be a battery charge warning light on the dash.

FWIIW, remember to disconnect the battery negative before starting electrical work.

If there was an arc during the work, likely something has burned out. Again, did you check all of the fuses?
 
If the battery terminals are not clean, corrosion free, and tight, this could be the source of the problem.

If the key is turned to "run" (do not start), does the dash battery light come on? Did you CHECK the fuses?

What is the voltage at the battery?

The Mustang GT's alternator is stupid easy to change. If $$ is tight, get a salvage yard alternator. Should be around $50.

Try car-part.com or Yellow pages.

It does seem like the alternator is fried. However, there should also be a battery charge warning light on the dash.

FWIIW, remember to disconnect the battery negative before starting electrical work.

If there was an arc during the work, likely something has burned out. Again, did you check all of the fuses?

You might wanna listen to Burns, I had a voltage Spike that ended up in one my COPs, the spike completely gutted the insulation, thank goodness the car was smarter then I was and threw a DTC. Burn's explanations are pretty elementary so that you could understand.
If you don't have the cash for a new alternator you can probaly rebuild yours, if that seems to be your problem.
 
The fuses are good, the fusible link is good. As far as corrosion the while i was replacing the terminal on the hot i cleaned the post so its clean and tight. I took the ground off and cleaned it as well. I checked the connector where it plugs in the back of the altenator and it its clean and extremely tight. I hate it but id say wmburns is right and the altenator is shot. Its not that we cant afford it my wife is very tight with money.

When i turn the key to on without starting, i can in fact see the battery light indicator.

Based on the voltage according to the dash its at like 8volts right now. Prior to all this when it was running it was over half way probably like 14volts.

I overslept and didnt get to take it to the autoparts store today. Im off tomorrow so ill get it done then.

Thanks again for all the help. Ill post the results and stuff of the altenator test and let you know if i get the new altenator and get it fixed.

Thanks guys
 
Its not that we cant afford it my wife is very tight with money.
:owned:

So how did your manage the big sound system? :cool:

OBTW, remind your Wife that the car can not be driven without an alternator. So this falls under the heading of a "required repair".

It also sounds like you have some burned out dash warning lights as ALL lights are supposed to come on during the initial key on test.

OBTW2, when you installed the sound system, did you mess with ground G204 located to the left of the center console? This ground is shared by the cluster, GEM, AC/heater blower motor, and the RADIO. A problem with this ground sure could cause a lot of strange issues.
 
Ok I have honestly had that stereo (the JL subwoofers) since i was like 16 or 17 (23 now) i got them for christmas from my parents one year. I got the amp for putting a transmission in a 97 saturn SL2.

In reality i have a more expensive stereo that i coulda put in there but I wouldve had to build a box for the subs and buy a capacitor not to mention i woulda had to buy a 4 gauge wire (it was in my camaro and the box is to tall for the trunk of the mustang. The other stereo is 2 12" Kicker solobaric L7's and a planet audio 2250W monoblock class d amp).

I had/have a decent paying job and up until about 1.5-2 yrs ago when i moved in with my gf(now my wife) bc my parents died all i had to pay for was car insurance and my cell phone. I had alot of money to waste on my car. Got engaged had to start paying bills but i still have alot of goodies i have from previous vehicles. I have 18" Konig Kolors that i could put on the stang but i dont think they would look as good as the 17" torq thrust factory rims.

My wife responded to your OBTW: she said that i should clarify that we work at the same place, same shift and she has her own car. Basically saying it can wait til i get my "allowance" so to speak and we can take her car (07 prius hybrid) to work. Which we take pretty much all the time anyway bc of gas mileage.

Answer to your OBTW2: no i didnt mess with that ground wire. I know for a fact that i have an issue with the service engine bulb the guy told me it wasnt working when i bought the car. All the other effected things you listed are working fine (ac blower, radio, etc.)
 
The other stereo is 2 12" Kicker solobaric L7's and a planet audio 2250W monoblock class d amp)
FWIIW, the stock GT's alternator is 105 amps (or so). The car itself needs about 60-80 amps to run. This leaves 25 amps for "other" things.

25 amps at 12 VDC will support 300 Watts. (power = voltage * current). At times, there will be more/less power available depending upon what is running (AC, head lights, idle, UD pulleys, battery charging).

A 2250 Watt sound system could represent almost a 6-10 times over load of the stock alternator. It is simply not possible to get 2250 Watts of sound power out with only 300-500 Watts of power in.

This is Ohm's law and is not BS. If you can find a way to beat Ohm's law, please let me know. Because we can solve the world's energy needs and retire richer than Bill Gates.

I'm not saying that the system is not loud or good or anything like that. What I am saying is that anyone buys a sound system that big and doesn't do anything to beef up the charging system is leaving some on the table. There simply isn't enough available power to max it out.

Now in practice, current draw in excess of the alternator's capacity would be made up by the battery. Obvisouly the battey is capable of suuporting some very sizeable loads. However, at that point the battery is being discharged and this can not continue forever.
 
FWIIW, the stock GT's alternator is 105 amps (or so). The car itself needs about 60-80 amps to run. This leaves 25 amps for "other" things.

25 amps at 12 VDC will support 300 Watts. (power = voltage * current). At times, there will be more/less power available depending upon what is running (AC, head lights, idle, UD pulleys, battery charging).

A 2250 Watt sound system could represent almost a 6-10 times over load of the stock alternator. It is simply not possible to get 2250 Watts of sound power out with only 300-500 Watts of power in.

This is Ohm's law and is not BS. If you can find a way to beat Ohm's law, please let me know. Because we can solve the world's energy needs and retire richer than Bill Gates.

wm, you're assuming the system draws 2250W continuously. Were this the case, I'd agree. However, a normal stereo (i.e. not one of those ludicrous dB contest rigs) only draws anywhere close to that sort of power on a very transient basis, such as deep bass hits. The average draw of such a system is very much lower.

And for those transients, as you note, the battery itself is a massive well from which the amps can draw current. A good analogy are so-called "stiffening caps" that are often installed near an amplifier to provide a low-impedance source of current for bass hits, current that can be supplied instantly and without I^2R losses through long cables: The cap supplies the instantaneous current -- and it may be thousands of watts (though over a very short period of time) -- and the cap is then recharged through the power cables from the battery/alt before the next big bass hit.

The alt must be up to the average power draw, not necessarily the maximum rated power. Aside from rough estimates, the only way to really know for sure would be to put an ammeter (capable of measuring a hundred or more amps) on the positive lead off the battery and measure the RMS current draw with the stereo on and the vehicle accessories running.
 
Well put trinity and i did specify i would have to buy a capacitor for this system. The capacitors come in different sizes for larger systems called farads. Not to mention peak wattage on the solobarics i have is 750watts so i would have to turn the amp down to about 2/3's power so then id only be pulling around 1500 watts. My 87 camaro z28 305 TPI ran the system fine for almost a year with a 1farad stinger capacitor.

I had also considered running a 2 battery system for this purpose as well. But as you can see this would have been alot of money to put into the car to get it to sustain that stereo thus the reason i went with the JL W0's instead. they are only 250-300 watts. So wiring was also musch cheaper.

In my younger years it was all about having the best everything in my school. It was like a competition to the guys in my school. When it came to stereo i pretty much won that battle with the stereo above. But now its like id rather keep my eardrums and just have something that puts out a nice moderate bass.

As far as the my wife stuff its really a big joke around the house. I have X amount of money im allowed to go waste on my car, video games, etc. Well aside from that im not suppose to use the other money for anything of the sort. Well since i got the mustang ive constantly found myself using the other money as well. Point being she has tried to get me to quit wasting large sums of money (as ever wife pretty much does) and i continue to do so.

On a more serious note I called parts stores the cheapest altenator they had was $214. I called all the local salvage yards even some over 50 miles away and none of them had an altenator for my car. So i also called a shop that rebuilds altenators they said bc it has the 130amp altenator that it could be anywhere from 50-125 to have it rebuilt depending on what was wrong with it when they open it up.

Gdawg, as specified in several of these posts i do intend to take it to the autoparts store and have the altenator checked. I work from 10:30am-9pm so it is difficult to do anything after work cuz everything is closed, it is difficult to do anything before work because im not a morning person and i have to leave my house at about 9:30 to be to work on time. I was going to go yesterday morning before work but overslept. Im goin to take in about an hour or so.
 
Ok, took the car to the autoparts place. I was told over the phone i could have it tested in the car. Well i took it down there the machine they used only hooks to the battery to check if there is any charge going to the battery. So they check it and say it isnt charging, i was like "tell me something i dont know." He did confirm my battery was good, again i was like well go figure i mean it did just sustain the car for a few mile drive, and started it twice. So i had to take the car home pull the altenator (as WM said very very easy took longer to get the tools out that to pull the alternator) and took it back down to have it bench tested.

After looking at the altenator the guy was like WTF how am i suppose to test that thing, ive never seen an altenator like that. :eek: At this point im like you have got to be kidding me... He had to go help another customer. While he walked away i loaded it into the machine and put the belt on it. He asked another worker to come show him how to load it. The other guy walkks back and looked at it and says, "just like it is." So he tests it that way and he said its charging, then notices the diode light is on and tells me i have a bad diode.

Altenator shop is closed for the weekend already. Ill let you know what they say, as far as how much itll cost.

Thanks for all the help guys.
 
Well put trinity and i did specify i would have to buy a capacitor for this system. The capacitors come in different sizes for larger systems called farads. Not to mention peak wattage on the solobarics i have is 750watts so i would have to turn the amp down to about 2/3's power so then id only be pulling around 1500 watts. My 87 camaro z28 305 TPI ran the system fine for almost a year with a 1farad stinger capacitor.

Note that the cap only improves the performance of the amp to hit the bass driver with a burst of current. It doesn't really make life easier for the battery or alternator. The cap is a very low impedance reserve of energy that is placed physically close to the amps in order to minimize the voltage drop that occurs when large current demands are placed across a power cable (even a large one.)

All of the energy to supply your electrical system ultimately comes out of the alternator, caps or not. It recharges the battery and the cap(s). It's ability to keep up depends largely on the average electrical demands.

A high power stereo that draws peaks of 100A for 200mS every 2-seconds could be said to have a duty cycle of 0.2/2 or 10% for the heavy load. Assuming the stereo draws a steadier 20A the rest of the time. If the alternator is capable of supplying 30A ((100A * 0.10) + 20A) in steady state, it can theoretically supply that demand. Now, if you add the current required by the rest of the car (as wmburns said, a car's system might require upwards of 60-80A steady state for things like the blower motor, the rear defogger, the car's exterior lighting, the wipers etc etc) and you're adding another 30A average requirement for the stereo you're edging into the upper limit for the factory system.

I had also considered running a 2 battery system for this purpose as well.

Unless you run a second alternator you'd still end up with a problem. Every ounce of energy removed from a battery, whether for the starter or for a stereo must be replenished by the alternator. One battery or two or ten, it wouldn't matter: Ultimately the ability to keep the battery(s) charged is a function of that which is drawn out of them versus the alternator's ability to put energy back in.

It doesn't have to be put back in as fast as it's taken out (that's where the load duty cycle and steady state values come in...) as long as it's put back.

A high-output alternator -- such as the 200A unit put into Crown Vic police interceptors -- would be what you really wanted. They are designed to cope with all the additional lighting and electrical demands made for police duty.
 
all that being said, like i said earlier I ran the same exact system in my camaro with a 1 farad capacitor and had no issues. The only effect i ever noticed was at night when i had the stereo going. The lights would dim a bit when the stereo hit really hard. Never had any alternator issues or anything. But thanks for the info.
 
I guessed alternator from the start, I would also guess that the battery could have a bad cell or will be bad soon enough. I would upgrade to an Optima red top, whatever the biggest one you can fit in is. And as far as Capacitors, I wouldn’t bother. The guys at pioneer took all the caps out of their competition vehicle and made an extra couple of dbs. If you want to get a cap, get one of the hybrid battery capacitors, they work much better.