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Topic: new parts - still not charging (Big story) (Read 2858 times) previous topic - next topic

new parts - still not charging (Big story)

Just some background info: car is a 1983 Mercury Cougar LS, 302 Carb'd, AOD trans, with a Holley carb(electronic choke, vacuum secondaries), A/C removed, Emissions air pump removed. everything else is stock if not original, then brand new.

OKAY, so i tried taking the cat out for a drive a day or so ago, and when i get to my destination it dies out, i figured well, must be the alternator, since the battery was just replaced. so i run back the next day and rip out the alternator, replace that, and just for kicks i swapped the old 3 pin starter solenoid and changed it to a new 4 pin unit, figuring this had better work, if it doesnt my life is gonna suck.

so i try starting her up again, boosting was required, and she runs and holds herself nicely, but when i throw a mulitmeter on the battery to check that my new alternator is running up to spec, im getting a 10.5V out of it, and all its doing is dropping. so then i check the positive side of the alternator, to see if i get a voltage drop. BAT terminal on the alternator to the POS on the battery gives me a 7.65V reading. so im goin "Well theres the problem!" thinking the wires are shot.I then take a peek at the 28 year old wires bridging the Alt-Starter relay-battery, to find what has to be 6 fusible links and a butt connector that has to have replaced a f-link.

We tried running a hard line straight from the alternator to the battery eliminating the start-solenoid, and it does nothing, the battery still leaks power since its running the engine, and the alternator isnt doing a single thing. Also tried disconnecting the battery while the car was running, theoretically it should remain so, it died instantly.:punchballs:

now for the questions:

1. Do these cars have a common spot in the harness that blow if say the battery is hooked in backwards or there was a random power surge? (the location and existence of the butt connector suggests it was at some point)

2.Are fusible links directionally biased? (like a diode would be)

3. if I ran hard lines from the battery to the starter solenoid, solenoid to the starter and solenoid to the alternator, could i theoretically get a charge out of the system, all the while eliminating all of the fusible links. And if so, what would i be disabling/ would i be hurting the car's electrical systems?

4.this is the big one. with enough wiring, keeping in mind the car was originally a carb'd automatic, and still is. Could i build my own wiring harness using basic engine theory, connecting the start/charge/ignition system. eliminating a whole whack of what i consider to be useless wiring(the stack of f-links) and any real ECM system that would be essential if the car was injected, but is just spare parts on a carb?


Now im going to run outside and take a few pictures to post here, and ill reference them to my whack of questions. I also have access to what i believe to be an EVTM and a bunch of other resource material on the car's systems, but i want an opinion from you guys who undoubtedly have much more experience not only  in this field, but in specifically these cars. :bowdown:

Thanks for the Help!
1974 Cougar XR7, 351 C, stock. white leather.
1983 Coug' LS-XR7-1/ A/c Delete, Edlebrock Intake, Holley 600 4bbl, Custom Badging, True dual Glasspacks
1989 Pontiac Bonneville SSE, 3.8L bone stock winter beater, in Gold

new parts - still not charging (Big story)

Reply #1 –
and now for the pictures:

starter solenoid. Notice the Butt connector lower middle of pic, i believe that used to be a fusible link.


Back of the alternator, I matched the hook ups from the original. they where laid out identically, the only difference between the two was the pulley, new one had a single V type and the old one had a multiple V similar to a serpentine setup. I do still have multiple belts, changing the pulley was pretty simple.


General overview. left to right, the first arrow is the new solenoid/ butt connector fiasco. Second arrow is wiring coming out of the back of the alternator, and merging with a larger set. the third arrow is a "duraspark" box i would like to eliminate/move (rewire) if possible. fourth arrow up top is a large plug going into the firewall. i suspect its for the idiot lights on the dash.


better view of the "duraspark" box and firewall plug.
1974 Cougar XR7, 351 C, stock. white leather.
1983 Coug' LS-XR7-1/ A/c Delete, Edlebrock Intake, Holley 600 4bbl, Custom Badging, True dual Glasspacks
1989 Pontiac Bonneville SSE, 3.8L bone stock winter beater, in Gold

new parts - still not charging (Big story)

Reply #2 –
Quote from: Coldcougar;360458
BAT terminal on the alternator to the POS on the battery gives me a 7.65V reading.

That is suspicious. Disconnect the wire from the alternator BAT terminal and the POS battery cable from the battery and check the resistance from the battery cable to the alternator wire.
 
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a butt connector that has to have replaced a f-link.

Yes the green fuse link has been patched with some yellow wire.

Quote
1. Do these cars have a common spot in the harness that blow if say the battery is hooked in backwards or there was a random power surge? (the location and existence of the butt connector suggests it was at some point)

The patched green fuse link is the one that would blow. It goes to the alternator and the voltage regulator. Reversing the battery polarity causes the alternator to become a dead short to ground. 

Quote
2.Are fusible links directionally biased? (like a diode would be)

No

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3. if I ran hard lines from the battery to the starter solenoid, solenoid to the starter and solenoid to the alternator, could i theoretically get a charge out of the system, all the while eliminating all of the fusible links. And if so, what would i be disabling/ would i be hurting the car's electrical systems?

Removing the fuse links is not a good idea. You would be exposing yourself to an electrical fire. If that blown green fuse link had not been there the wiring may have caught fire.
You should consider replacing the green fuse link.

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4.this is the big one. with enough wiring, keeping in mind the car was originally a carb'd automatic, and still is. Could i build my own wiring harness using basic engine theory, connecting the start/charge/ignition system. eliminating a whole whack of what i consider to be useless wiring(the stack of f-links) and any real ECM system that would be essential if the car was injected, but is just spare parts on a carb?

Already talked about the fuse links. I don't think your car has any wiring that is only needed for fuel injection. I suppose you could take out the wiring for the AC compressor clutch.

1. Charge up your battery.
2. Turn the ignition to run. Do not start. The Alt/Batt light on the dash should be on.
  Before the alternator can have an output it has to be excited (turned on). With the key on, voltage goes through the Alt/Batt light to the "I" terminal of the voltage regulator. This should turn the light on and cause the voltage regulator to turn on the field current to the alternator. F terminal of the  voltage regulator to the F terminal on the alternator.
If you feel around the alternator with a long screwdriver you should feel the difference in magnetism between key on and key off. (remember we have not started the car yet)

Let us know what you find.

new parts - still not charging (Big story)

Reply #3 –
okay, first thanks for the reply. I followed the instructions, and i have some results for you.

the resistance on the wires from the BAT terminal on the alternator to the POS terminal on the Battery came out as 29.7 ohms. i also broke it down further and measured 30.6 ohms on the wire from the alternator to the starter solenoid.

I also tried getting a magnetic field out of the alternator when the key is in the on mode, and there was no difference. now im not sure how drastic the difference from on to off should be but i couldnt feel anything change.

I want to mention as well, there are two posts on the starter solenoid one marked "S" and one marked "I". following instructions i attached the small red/blue strip wire to the "S" post of the solenoid.(not sure if this is the "I" terminal  you mentioned above. I believe the voltage regulator is inside the alternator, considering there is a "field" post on the back of the alternator housing.)
1974 Cougar XR7, 351 C, stock. white leather.
1983 Coug' LS-XR7-1/ A/c Delete, Edlebrock Intake, Holley 600 4bbl, Custom Badging, True dual Glasspacks
1989 Pontiac Bonneville SSE, 3.8L bone stock winter beater, in Gold

new parts - still not charging (Big story)

Reply #4 –
one last addition, considering it is something that I have been meaning to do for a long time, I replaced the main battery cables with new wires, just for kicks the resistance on the positive cable from the battery to the solenoid measured 0.03 ohms
1974 Cougar XR7, 351 C, stock. white leather.
1983 Coug' LS-XR7-1/ A/c Delete, Edlebrock Intake, Holley 600 4bbl, Custom Badging, True dual Glasspacks
1989 Pontiac Bonneville SSE, 3.8L bone stock winter beater, in Gold

new parts - still not charging (Big story)

Reply #5 –
Quote from: Coldcougar;360539
okay, first thanks for the reply. I followed the instructions, and i have some results for you.

the resistance on the wires from the BAT terminal on the alternator to the POS terminal on the Battery came out as 29.7 ohms. i also broke it down further and measured 30.6 ohms on the wire from the alternator to the starter solenoid.

The resistances are a little higher than I would expect but it is not an open circuit. Maybe the patch to the blown green fuse link is not the best, although it looks pretty.

Quote
I also tried getting a magnetic field out of the alternator when the key is in the on mode, and there was no difference. now im not sure how drastic the difference from on to off should be but i couldnt feel anything change.

If field current is flowing, you should be able to feel the magnetism around the center of the end cover or around the laminated plates.
You don't say whether the Batt(idiot) light is on. This is key info.
It shows that the "ignition on" voltage is getting to the voltage regulator.
I'm guessing you don't have a factory installed ammeter or a non stock instrument panel. Sometimes when people swap in an instrument panel that does not have the idiot light, they forget to tie together the two wires that used to go to the idiot light.

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I want to mention as well, there are two posts on the starter solenoid one marked "S" and one marked "I". following instructions i attached the small red/blue strip wire to the "S" post of the solenoid.(not sure if this is the "I" terminal  you mentioned above.

No that is not the "I" I was talking about. Some cars have a ballast resister in series with the ignition coil. A wire from this "I" to the coil would bypass the resister and put full battery voltage on the coil while cranking. Your car does not use this system.

Quote
I believe the voltage regulator is inside the alternator, considering there is a "field" post on the back of the alternator housing.)

No, you have an external voltage regulator. Which could be bad.

1. Key off, should have battery voltage on the alternator BAT terminal and the
  voltage regulator "A" terminal.
2. Key on, Bat idiot light is on. Voltage to the regulator "I" terminal causes regulator to
    turn on the alt field current. Should have voltage on the alt "F" terminal.
3. Start, Alternator Batt terminal should be 14.5v . Alternator "S" (stator) terminal should
  have ½ the output voltage(about 7v). This goes to the "S" terminal on the regulator
  and takes over keeping it turned on and opens the "I" terminal circuit, turning the
  idiot light off.
  This stator voltage also goes to the automatic choke heater. This way the heater
  doesn't start to open the choke until the engine is running.

You will not have fuse links L and M, but the rest of this diagram should match your car.

new parts - still not charging (Big story)

Reply #6 –
sorry about that, the batt light is on during the magnetic field test. And the dash is the original with no ammeter/voltmeter, just the fuel guage, speedo and lights for battery, brake, engine, high beams, and seatbelts.

ive had an idea. could i completely cut out the former green fuse link and all of that wire, including the wiring going to the voltage reulator(its bolted to the fender), and replace it with new wire, with a fuse holder and fuse in series. so that there is circuit protection. then if that doesnt work, i start testing/if needed replacing the voltage regulator.
1974 Cougar XR7, 351 C, stock. white leather.
1983 Coug' LS-XR7-1/ A/c Delete, Edlebrock Intake, Holley 600 4bbl, Custom Badging, True dual Glasspacks
1989 Pontiac Bonneville SSE, 3.8L bone stock winter beater, in Gold

new parts - still not charging (Big story)

Reply #7 –
i just called my local parts store, and they have a pile of v-regulators in stock, she said they had 50, 60, 75, and 100 amp regulators. would there be an issue if i went for the 100, or do i have to match the original?
1974 Cougar XR7, 351 C, stock. white leather.
1983 Coug' LS-XR7-1/ A/c Delete, Edlebrock Intake, Holley 600 4bbl, Custom Badging, True dual Glasspacks
1989 Pontiac Bonneville SSE, 3.8L bone stock winter beater, in Gold

new parts - still not charging (Big story)

Reply #8 –
Quote from: Coldcougar;360572
i just called my local parts store, and they have a pile of v-regulators in stock, she said they had 50, 60, 75, and 100 amp regulators. would there be an issue if i went for the 100, or do i have to match the original?
  HUH ??? Call a different parts store .
 Here is a quick way to test the regulator  . unplug the regulator  and jump the "A" and "F" terminals in the regulator plug .....if the alternator is charging it will max it out if its not then replace that goofed up fuselink and try again .
Fox-less at the moment

new parts - still not charging (Big story)

Reply #9 –
okay, ill give that a shot. just as a side note, what are the specs on the green fusible links? they should be the same as your average fuse, but im not sure if the color code limits of the metal are the same.
im finding it almost impossible to buy new links, and i might be forced to solder in a fuse holder.
1974 Cougar XR7, 351 C, stock. white leather.
1983 Coug' LS-XR7-1/ A/c Delete, Edlebrock Intake, Holley 600 4bbl, Custom Badging, True dual Glasspacks
1989 Pontiac Bonneville SSE, 3.8L bone stock winter beater, in Gold

new parts - still not charging (Big story)

Reply #10 –
Hey guys found the problem. I took hypostang's advice and bridged the terminals on the voltage regulator plug. cranked right over and the battery jumped up to 14.99-15 volts. saw alot of green death on the plug too. im going to clean up the plug as best i can and then head out in a day or so and procure myself a new regulator, and some fuse wiring to finish off the job.

Thanks going out to softtouch and Hypostang!
1974 Cougar XR7, 351 C, stock. white leather.
1983 Coug' LS-XR7-1/ A/c Delete, Edlebrock Intake, Holley 600 4bbl, Custom Badging, True dual Glasspacks
1989 Pontiac Bonneville SSE, 3.8L bone stock winter beater, in Gold
 

new parts - still not charging (Big story)

Reply #11 –
Good news !! , always glad to help
Fox-less at the moment