Charging System problems, etc.

[JaredR]

Okay, I have a handful of problems with none other than electrical crap.

To keep it simple first and foremost problem I'm having is my alternator is obviously not recharging my battery. Brand new Optima red top, new remanufactured OEM alternator, new voltage regulator.

Have tested and got voltage to the alternator but when the car is started and then the battery is tested the voltage slowly drops, never goes even above 12.. not sure what else to look for, could it be something with fuses or wires? It doesn't make sense to me that that'd be the case since everything gets power just fine, just can't get it to recharge my battery. Maybe something not hooked up right? Would absent grounds in certain areas cause it to not charge the battery?

If any other info is necessary to try and diagnose this, just ask.

it's an 1983 Mustang GT 5.0 4 Barrel H.O.

[SRM351]

As long as the OEM wiring isn't hacked, it's doubtful you have it hooked up wrong. It sounds like maybe the regulator isn't telling the alternator to charge. You said you have power at the alternator but which terminal did you measure from?

[TuxStang]

Don't know if it's still wired the same way in '83, but we had a charging problem on a friends '79 ... after he replaced the alternator and regulator, charging problem was still there. Took us half a day (it was a pain to follow it) to realise that the green wire of the regulator was running through the instrument cluster, on the smallest connector ... that connector wasn't properly fitted

[83-Steaman]

how about a burned fuseable link?

[JaredG]

This is probably a longshot, but did you recently change to an aftermarket carburetor? There are two electrical plugs on the stock carb. One is for the dashpot solenoid and the other is a WOT cutout switch. That cutout switch disables the alternator and the A/C when the throttle is wide open. If it's unplugged, electrically it's just like it would be with the throttle wide open.
I found this out the hard way after doing a carb and intake swap on my '84.
Good luck with it.
Jared G

[JaredR]

SRM351: from the positive.

TuxStang: i know exactly what you're talking about, there's the green wire running from the starter relaying into my harness and that goes to my firewall, but i think it changes color along the way, or i didnt look hard enough. ill check that out.

83-Steaman: a lot of fusable links but if one was shot would power still reach the alternator? or do one of those wires allow a lot of things to function right?

JaredG: yes i did, and i know which two wires you're talking about.. i have a new Edelbrock 600 CFM(wish i had gotten a Holley) but even if i got a new holley they dont have the same wires and all as my stock one correct? should i look into rebuilding my Holley? or can i get around it?

[TuxStang]

TuxStang: i know exactly what you're talking about, there's the green wire running from the starter relaying into my harness and that goes to my firewall, but i think it changes color along the way, or i didnt look hard enough. ill check that out.

It's a splice from a red/something (don't have my diagram at home) wire somewhere between the cluster and the ignition switch.

[JaredG]

JaredR - If you just did the carb swap and nothing is plugged into the WOT switch connector, that may be your problem. You can get around it, though.
You can make a jumper wire to bypass the missing WOT switch. Just get a piece of wire about 2" long and put male spade terminals on both ends. Then plug each spade into the terminals in the WOT switch connector. Make sure you don't plug it into the one for the dashpot solenoid or you will create a short.
I can get you a picture later if my description doesn't make sense to you. Let us know how it turns out.
JaredG

[JaredR]

JaredR - If you just did the carb swap and nothing is plugged into the WOT switch connector, that may be your problem. You can get around it, though.
You can make a jumper wire to bypass the missing WOT switch. Just get a piece of wire about 2" long and put male spade terminals on both ends. Then plug each spade into the terminals in the WOT switch connector. Make sure you don't plug it into the one for the dashpot solenoid or you will create a short.
I can get you a picture later if my description doesn't make sense to you. Let us know how it turns out.
JaredG

I'm no 100% positive what you mean, so a picture might help. was afraid id have a new carburetor stuck on my hands with an old one that needs a rebuild.

[wgt500]

Make sure you have good ground connections. Eng to -bat. cable at the block and eng. to chassis strap. Good Luck!

[JaredR]

Make sure you have good ground connections. Eng to -bat. cable at the block and eng. to chassis strap. Good Luck!

oh i have thought about that, but im unaware of the importance of it.. I have a body to intake manifold bolt ground. intake is aluminum but then it should still ground since the bolt is going into my iron block right?

and i guess i should still take a wire from the negative terminal to the block and then i have a block to ground i believe but ill set up a better one.

thanks for all the help by the way all the input has been useful.

[JaredG]

I hope these pictures help. My harness is kinda butchered, but you can see what I had to do with the jumper. The other pic is the two plugs on the stock carb. The good part is the plug you need to put the jumper on has two terminals and the other plug only has one.

What are you planning to do with the stock carb? I have been wanting to get one because mine has a broken baseplate. Let me know.
JaredG

[JaredR]

well to be honest i was going to get some money off it from a recycling yard, cause i couldnt figure out anything else to do with it and it's rusty and all so didnt think anyone would want to buy it lol.

thanks for the pictures going to see if i can find parts to do this, might have to go buy a few things. I've been wondering if anyone knows.. does home depot/lowes sells small wires and like 8 gauge wire by the foot? to relocate my battery and for something such as adding in grounds..

and after this little nuisance is delt with ill be back for some questions on why none of my gauges work/work accurately

[JaredR]

ok im going to loop just one of the female connecters back to itself.. and that alone will fix it? and it just runs like there were no extra wires there to begin with, correct?

[JaredG]

I think you have it. The plug with two female terminals needs to have the terminals looped together. The other plug will have only one terminal and it should just be left unhooked.
That should get you charging again if everything was ok before removing the stock carb.
Let us know what happens.
JG

[JaredR]

ok i tried bypassing the WOT plug like you said but it didnt work. i have checked all fuseable links and they are good, as well as all wires coming from regulator, alternator, and battery. every single wire is hot including the alternator. i dont understand why 12 volts is reaching the alternator but no power is reaching the battery.

[JaredG]

The WOT switch being unhooked was definitely a problem, but it seems that it wasn't your only problem.
Do you have any diagnostic info to work from? Here's a link to some stuff from Autozone:
http://www.autozone.com/shopping/rep...00c1528004deb8
Hope this helps.

JG

[JaredR]

they have wiring harness stuff, ill have to read through it.. me and my friend have been to autozone so often during this whole restoring process, we pretty much are their best customers and everyone who works there knows us lol..

i thought your idea would of fixed it but there's obviously more to it.. you think we may have fried the regulator or something like that? going to check out the green wire to the cluster next... this is such a pain

[CapriGT]

Have you had the alternator bench tested? Could be defective.

[JaredR]

Have you had the alternator bench tested? Could be defective.

yeah, we had them test it before we left with it

[bigjason_5]

I can't remember the wire colors off the top of my head, but I had on my '84 mustang the same charging issue. It ended up being high resistance in a wire to the voltage regulator. You should have one wire that has 12 volts to power the voltage regulator, and there is another wire that supplies battery voltage so it knows how much output is needed from the alternator. I can't remember exactly which wire had the problem, but it's something to check. I have to run out right now for a physical therapy appointment, but I can see if I can look at a wiring diagram later to jog my memory. Also, if your gauges aren't working properly, check the connections there too. I seem to remember the ammeter being run in series somehow. Just a couple suggestions. Good luck.

[JACook]

OK, first, the WOT switch is a red herring. WOT switch only controls the A/C
clutch. There is no WOT alternator cutout function on the '83 5.0. Like the
TSAD module, this feature did not make it into production, even though some
of the documentation suggests otherwise.

If you have battery Voltage at the alternator output terminal, with the engine
not running, the fusible link is OK.

There are four terminals on the back of the alternator. They are output, field,
stator, and ground. Battery voltage being present at the output terminal is not
enough to get the alternator to charge, since this isn't a "one wire" setup.

First, verify the ground wire. Don't presume the alternator will ground through
the brackets. The engineers who designed it to have a ground wire did this for
a good reason.

With the engine stopped, you should see battery Voltage on the output terminal,
and zero Volts on the stator terminal. with the engine running, you should be
seeing about 14.6 Volts at the output, and about 7.5 Volts at the stator terminal.

If the output only shows battery Voltage with the engine running, the next step
is to measure the field terminal. The field terminal is the one that's closest to
the alternator centerline. If you're seeing 12 Volts there, and there's no output,
the alternator is defective. Period. Normally, you will see a voltage on the field
terminal that's proportional to the amount of output being requested from the
alternator. That is to say, the field Voltage is greater when battery Voltage is
low, and decreases as the system nears the ideal 14.6 Volts. The field Voltage
is supplied by the regulator.

You may have heard the term 'full field' testing. This is a pretty good way to test
the alternator function, but it's also a pretty good way to fry a solid-state regulator.
If you elect to do this test, disconnect the regulator connector. You would then,
with the engine running, connect the alternator field terminal to battery + while
monitoring the alternator output. Only leave it connected long enough to see
if you're getting output, or you can damage the alternator.

If you're not seeing Voltage at the field terminal, we need to figure out why not.
The field terminal is connected to the 'F' terminal on the regulator. Ford regulator
terminals are arranged I-A-S-F with the tabs facing you. On the '83 GT, that
would make the field terminal the one on the bottom. If you see Voltage there,
but not on the field terminal on the alternator, you've got a wiring problem. If
you don't see Voltage on the 'F' terminal, the next test is to see what you have
on the 'A' terminal. The 'A' terminal is the system voltage sense, and is spliced
into the main yellow wire that feeds the electrical system. This terminal should
have battery Voltage on it at all times.

Finally, you need to have the signal to the regulator that tells it to turn on. That
is the 'S' connector, and it is fed from the same circuit that feeds the Duraspark
module when the ignition switch is in the 'run' position. The 'S' terminal should
show no Voltage with the ignition off, and around 8 Volts with the ignition on.
If not, you have a wiring issue between the regulator and Duraspark module.
Otherwise, if the 'A' and 'S' voltages look right, but there's no 'F' Voltage, the
regulator is defective.

The regulator 'I' terminal is for the 'ALT' light, and is not used on cars factory
equipped with an ammeter.

[JaredG]

Jeff,
Is the function of the WOT cutout switch different on the '84 vs. the '83 5.0 liter cars? I ask because I can say with absolute certainty that my GT350 will not charge with the WOT switch unplugged. There was also another FEP member with a GT350 that had the same issue. The kicker is that I couldn't find a relationship between the two systems on the wiring diagram.
JG

[JaredR]

thanks for the input guys, ill check it all out sometime tonight and post what i come up with.

[JaredR]

ok with the car running i have:

-12 volts at A on regulator and battery
-12 volts at S on regulator
-2.5 volts at F on regulator and field at alternator
-0 volts at stator terminal

still no luck, we ran it for 5 minutes and the battery never left 12 volts. when i connect the field terminal and + battery terminal i get about 13.75 volts at the battery