67 Barracuda Heavy Electric Load

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Thank you everyone for your replies. I have read them all and working on getting more info. O’Reilly’s and Autozone would only test for good/bad on the alternator so I set-up an appointment tomorrow with an auto electric shop that say they can get actual amps.

Also, this may not be useful, but I did get a voltage reading from the battery after charging all night and the trickle charger shutting off - it came in at 13.11 volts.
 
DallasMan2000 said:
Also, this may not be useful, but I did get a voltage reading from the battery after charging all night and the trickle charger shutting off - it came in at 13.11 volts.
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That's called surface charge. There's energy at 13.11 volts but it will go away quickly. Go back and measure now and it will be at a slightly lower voltage.
 
DallasMan2000 said:
Thank you everyone for your replies. I have read them all and working on getting more info. O’Reilly’s and Autozone would only test for good/bad on the alternator so I set-up an appointment tomorrow with an auto electric shop that say they can get actual amps.

Also, this may not be useful, but I did get a voltage reading from the battery after charging all night and the trickle charger shutting off - it came in at 13.11 volts.
Click to expand...
Most (all?) parts store alternator checkers cannot test for full load output amperage, and MANY of these testers are either incapable, or the people operating them.

On a side note I build--from scratch and spare parts--an alternator tester back in early 80's at a parts store where I worked. Hand built ammeter shunts calibrated with the help of 2 or three different loads and load testers, meters were bought back then from Rad Shack. We happened to have a 15hp 3 phase motor in the back room, and so we used that. Biggest alternators I remember back then were large frame (heavy duty cycle) truck units, about 140-160A.

If you go to a real by god alternator/ motor rebuilder they likely can tell you.
 
Did you check voltage at alt. when running? I would think if it's say 14 or more then issue would be Regulator or wiring?
 
He is a video of the alternator gauge when starting with a 13.11 V charge in the battery on a 42 degree morning. Whoops, that did not work, the video evidently does not upload like pictures. So the needle went slightly towards the D when the car started then quickly moved back to the middle. I also measured 12.17 volts at the alternator post once the car started. Removing the alternator again and will hopefully have it tested this afternoon. The three photos are snapshots from the video. First is before starting, second is immediately after starting, third is about 30 seconds after starting.

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The headlights are just plain old stock lights. Also, the car came with the electric fan installed when I bought it last summer. The previous owner put the clutch fan in the trunk. I can’t remember if the 67 barracuda had a shroud around the clutch fan - I have no shroud other than the one made to fit the electric fan. Would it be a simple as putting the clutch fan back on? I recall the previous owner mentioning a HP gain when changed over to an electric fan……. Maybe 40 HP?
 
Don't discount silly and easy stuff like a loose belt.

Measure voltage while running/ charging BOTH at the battery (ground to block) and at the alternator output stud. If there is more than 1 volt difference you have harness problems.
 
DallasMan2000 said:
So the needle went slightly towards the D when the car started then quickly moved back to the middle. I also measured 12.17 volts at the alternator post once the car started.
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It should have moved slightly toward D (battery Discharge) while starting.
After starting it should have moved to C (battery charging) for a few minutes. Gradually returning to the center as the battery finishes charging.

Comparing with engine off, this last photo indicates slight discharging.
1704295951225.png

When the engine is running, discharge indicates the battery is supplying power to run the car.
Caveat: True only if the battery is the only item attached to the battery side of the ammeter.

DallasMan2000 said:
Removing the alternator again and will hopefully have it tested this afternoon.
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You can test a few things before doing that.
1. Remove the field terminal connections and check whether either field terminal is grounded. Using an ohmmeter or continuity setting touch one probe to a terminal and the other to the alternator housing. Check both terminals. If either is grounded. Stop. Alternator is set up as a grounded field alternator.
2. Check that the field circuit is complete. Touch one probe to each terminal. They should connect, although there will be resistance from both the rotor windings and the carbon brushes. If they don't connect, stop.
3. If it passes both tests, then with the engine running at slow idle, connect the ignition feed to the field circuit (blue wire), and connect the other terminal to ground. The voltmeter connected to the alternator output stud should jump up to 14 volts. Do not rev the engine as there is no votlage regulation duing this test.
This completes the circuit for powering the rotor.


DallasMan2000 said:
The headlights are just plain old stock lights.
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Look at the lens and you can get a bit more information. But this is side track for now. Start a different threwad if you're interested.

DallasMan2000 said:
Also, the car came with the electric fan installed when I bought it last summer. The previous owner put the clutch fan in the trunk. I can’t remember if the 67 barracuda had a shroud around the clutch fan - I have no shroud other than the one made to fit the electric fan. Would it be a simple as putting the clutch fan back on?
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We can't see the radiator in the photos. '67 was unique but similar to '68-69.
The water pump looks like its cast iron and likely the correct for pre-70 cars.
If so, then then yes all that is needed is the clutch and the clutch fan.
Shrouds are most helpful when the car is not moving, although Chrysler did not always deem them neccessary on non-A/C equiped cars.
DallasMan2000 said:
I recall the previous owner mentioning a HP gain when changed over to an electric fan……. Maybe 40 HP?
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Sure at the top end of the quarter mile.
Well maybe not 40 hp. That's a bit of hyperbole.
The clutch fan is somewhere in between no fan and an electric fan in terms of hp savings at high rpm.
Plus, turning the alternator, especially when its working hard, also crauses noticible drag on the engine.
 
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DallasMan2000 said:
So my 67 barracuda has an electric radiator fan and I have noticed that the car wants to die after about an hour of driving then coming to a stop light when driving at night. Wondering if the extra electrical load is too much for extensive driving. There is a high output Mopar alternator on the car now. It seems like even a standard alternator should keep up. Last night I drove for about an hour with lights and wipers on and electrical radiator fan running. Usually I have a trickle charger on the battery before driving but did not this time. When I got back home the car would die when I stopped it at an idle. Usually it starts right back up but this time it would not even turn over. I charged it up for about an hour and it started right up again so I could get it back into the garage.

Do I need a voltage regulator that allows more amperage to pass through during normal operation?
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Mopar alternators are known for notoriously low idle output at idle. Add the bulkhead's propensity to heat up, melt and catch on fire when anything more than even the stock amperage loads are flowing through it, and it is a thing. And, it can easily be addressed and the issues remediated using the information posted in this thread.

While the Spal products are good quality, the small fan you have will never come close flowing as much air as the mechanical Mopar clutch or thermal fan's capacity to move air with the right shroud and fan spacing. Period.

Any high amp draw accessories, are best fed from a dedicated 12v distribution lug (the starter relay stud is a great source), fed by a fused or circuit breaker protected (added) cable from the alternator directly to the 12v distribution point.

Each high amp accessory should be fed using relays and provided with its own ground wire back to the battery or negative ground contact near it. I run a like size ground from my alternator case back to the battery. Current flows through both cables to form a circuit, and proper sized ground returns are often overlooked.

I altered both my Mopars this way, but still wanted more amp output at idle. I bolted in a rewound CS144 with a heavy duty bridge rectifier in my '70 E-Body to have 115 amps at a low idle and up to 240+ amp output at a fast idle. The accessories I have don't draw that much amperage in total, but they do draw more than the what the Mopar alternators are capable of producing at idle.

Even the Denso's don't put out much more that the Mopar alternators at idle. They are better, but not ideal if you want high load accessories like dual fans, big fuel pumps, A/C and big stereos.

I painted my CS144 matte black and no one has ever noticed it is not the stock Mopar alternator. There are many ways to skin a cat, and several are posted prior to the way I skinned mine.

IMG_2602.JPG
 
Mattax said:
Caveat: True only if the battery is the only item attached to the battery side of the ammeter.
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It will be helpful to figure out the wiring modification.

We can see two wires into the passenger compartment have been squeezed through the speedometer cable grommet.
What do they connect to?
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Power to the electric fan is a heavy red wire. Likely this is the red wire from the relay above the rain gutter.
Therefore the heavy yellow wire probably is the power feed to the relay. Where does the other end of the heavy yellow wire connect?

Here's a good photo of an unrestored '67 Valiant as a comparison.
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DallasMan2000 said:
Here are some voltage readings:
12.57 before starting and after letting the car cool off and electric radiator fan off
12.22 when I started the car and the electric fan had not kicked on yet
12.00 with the car running and the electric fan kicked on

It is back on the trickle charger now and will get another reading at the battery in an hour or two.
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Yeah, that alternator isn't working.
You should be getting 13-14 volts after the motor fires up.
The alternator or the voltage regulator, one of them has given up the ghost.
(I use "cigarette lighter voltmeter," a little cheap thing for testing or monitoring.)
 
DallasMan2000 said:
I recall the previous owner mentioning a HP gain when changed over to an electric fan……. Maybe 40 HP?
Click to expand...
not in his wildest dreams did it pick up 40hp by going to electric fans, especially with a clutch fan that freewheels a good deal of the time when driving. I would think less than 10hp...
 
You gain some HP from eliminating the fan, Motor Trend looked into this (Engine Masters Episode 20), it could even be up to 30 hp according to their testing.

(I deleted my clutch fan because I wanted the free space back in front of the engine! The electric fans are thermostatically driven, they cycle as needed and work "good enough" for my needs.)

 
Which is great if the engine can run without a fan, he can save around 31 horsepower at 5100 rpm over a fixed mechanical fan which he was never considering.
But to be really fair, I did not see an alternator on the front of that 350. So with an electric fan, unless he kills the fan or the alternator during the 1/4 mile run, there's drag from the alternator's magnetic field.
So its not 40 hp, its not even 30 hp over a big fixed blade fan. He was asking about a clutch or thermal clutch fan which he already owns.

What Dallas is asking about is why there is a problem with his "charging" system.
So there are two reasons why the electric fan is relevant to his question.
1. Depending on how it was wired, it may be confusing the ammeter readings.
2. Depending on how it was wired and how much power it draws, it may be overloading a circuit, or the capacity of the alternator at low rpm.

As he is not that familiar with electrical, and we are not there, switching to the factory fan is likely simpler and will cause less damage than reworking the original wiring strategy to accomodate this fan. And even if that was all done, from the photo I would not bet that the fan and shroud will be effective on long distance drives in the summer.
 
I guarantee to you that if the battery is registering 12.22 volts when the motor is running, that's because the alternator is dead.
Something has expired between the alternator, the voltage regulator, maybe a fuse somewhere, or the wiring got nibbled by a porcupine in the dead of night!
 
Looking back at this post, the alternator was providing some power at that time.
Based on the two threads, its seems the modifications to the harness are likely related to the problems.
 
Grunchy said:
I guarantee to you that if the battery is registering 12.22 volts when the motor is running, that's because the alternator is dead.
Something has expired between the alternator, the voltage regulator, maybe a fuse somewhere, or the wiring got nibbled by a porcupine in the dead of night!
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Well if its a wire two or from the field, or the regulator, then the alternator is probably not dead. Already posted an easy test to eliminate the VR possibility.
Agree in some parts of the country it could have been a porcupine in there, but all the signs here are just some well intentioned human.
 
Grunchy said:
I guarantee to you that if the battery is registering 12.22 volts when the motor is running, that's because the alternator is dead.
Something has expired between the alternator, the voltage regulator, maybe a fuse somewhere, or the wiring got nibbled by a porcupine in the dead of night!
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I think you meant that "THE CHARGING SYSTEM" is dead.

NOTE THAT the initial statement is misleading. Either the charging system is dead or the battery is way down OR defective and will not "come up.

But it does not mean (as explained) that "the alternator" per se is the culprit

I would temporarily swap in a known good and charged battery. KNOWN!!

I would figure a way to load the system to max amperage, heater, lights, etc, AND FANS

If the voltage will not regulate to nominal 14V, then "full field" the alternator, that is, bypass the regulator

Do this first by removing the green field wire from the alternator, and connect a jumper from that now exposed alternator field terminal to ground. Watch the voltage and do not allow it to increase above about 16V

If it will not, remove and inspect alternator. READ the service manual in the electrical section concerning field current draw test. Remove and inspect brushes for wear, spring and free movement, debri, grease and oil.

The main problems with a low output alternator are:

Poor brush contact, or field winding problems
Bad diodes, either 1 or more
Stator winding problems, which can be a partial open in one winding, partial shorts, etc etc. Sometimes you can SEE these physically. Burned toasted wires, loosened up from vibrations and rubbing, etc etc.
 
OP - Does the wiring for the regulator (wires to triangular plug) appear to be a part of the M&H harness (wires coming out of the wrapped harness)?

If so, again, I would bet that the upgrade to the later voltage regulator was done by having M&H build it that way, which is an option that they offer on their under hood harnesses for earlier cars, as opposed to a PO wiring it in by the seat of their pants. That of course does not mean the the VR is operating correctly. And does not mean that the fan harness with relay is not incorrectly wired. If the OP disconnected the fan and started the motor cold, could he run it for long enough to see if the electrical issue goes away? The water pump is still driven by a fan belt.
 
I dropped the alternator off at Auto Electric Systems in Dallas. They had planned to test while I waited but the person running the tester had left for the day and will get to it tomorrow morning. They asked lots of good questions and seem to have the correct equipment to get a good test.

The electric fan does not kick on until 180 degrees so it takes 5 to 10 minutes after starting to kick on. So the Alternator gage picks I posted this morning did not have the fan running.

I have noticed an occasional alternator belt squeak right after starting but the belt seems adequately tight. Will definitely make sure it is tight when reinstalling an alternator (maybe new) tomorrow.
 
These is a lot going on at the starter relay - see pic below. The large black wire coming in to the top comes directly from the alternator post.

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The battery is fairly new - see pick below. Will take it in for a test if we still think it may be an area of concern.

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The yellow wire from the fan relay goes to an inline fuse then to a red wire that you can see bolted to the positive battery connector. The red wire from the fan relay goes to the starter relay and is the bright red wire that come into the top.

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