Is my alternator wired correctly?

[mauibarber]

I have had my 69 Charger with a 440 for about 8 months and to my knowledge there has always been a brown wire loose by the alternator.  I have a heavy duty alternator that has two field connections and of course the Battery connection.  I see this brown wire going into the resistor but it is not connected to my Alternator.  Plus there is no male end on the open field connection for the brown wire to hook onto, so I would have to put one on.   Is there any way that this brown wire does not need to be connected to the open field connector?  Can you wire a alternator with two field connections and only use one field?

I have been having problems with the charging system lately and am wondering if this has anything to do with it.  The car just doesnt seem to be charging enough to keep the battery up so after a couple months i gotta recharge it.  But I don't wanna connect that brown wire and fry my alt.  Any suggestions? 

The big question is, if this is supposed to be connected and its not what would be the symptoms if this field wire is not connected to the resisitor?

Here you can see the brown wire at the resistor.


Here you can see the loose brown wire and right above my finger is the open field spot on the alternator.


And here you can see the top of the alternator has a green wire coming out of the  field position being used that goes to the voltage regulator on the first picture, below that is the open unused field spot and then below that is the battery connection.

[Ghoste]

I believe the brown wire at your resistor is coming from your ignition switch.  As for the unconnected one by your alternator, I don't know.

[John_Kunkel]

A brown wire in the vicinity of the alternator is probably for the windshield washer motor mounted (if equipped) on the passenger side fender panel.

A voltmeter across the battery terminals when the engine is running will show the charging rate.

[Rolling_Thunder]

Brown wire is not an alternator wire...    it goes to your windshield washer pump

You are having charging issues because you are running a dual contact alternator with a single contact voltage regulator...     simple ground the 2nd (unused terminal) on the alternator to the alternator case itself....      you should then charger quite fine.

I could tell you why that is - but i'm sure not going to type it all out    lol    I just put a harness in a 69 Coronet Vert and I am spent on electrical at the moment.

[Nacho-RT74]

I could tell you why that is - but i'm sure not going to type it all out    lol    I just put a harness in a 69 Coronet Vert and I am spent on electrical at the moment.

That is because pre 70 charging system are with mechanical regulator and single field alt from external sources what is regulated positive coming from regulator. Regulator takes the power from ignition switch ( blue wire ). Negative is constant throught a brush grounded on alt housing itself.

70 and laters alt are with two prongs. These alts are called DOUBLE FIELD, and they are both externally feeded, but this time Negative is the regulated source coming from ELECTRONIC regulator. Elec reg takes the power from firewall ( chassis ground ). The other brush is CONSTANT positive being directly feeded by ignition switch blue wire.


mauibarber:
Definitive there is something weird on that wiring. Brown heavy wire at ballast shoud it be TWO brown wires, one coming from ign on start position and the other running to + lead of coil.
I can see a black wire on regulator that I don't know why the hell is there.
I see too many bleu wires around LOL, and should it be just one input to regulator and one input to ballast... of course Ignition module too being spliced from one of those since was added.

an advice... change for electronic regulator if you want to get a good performance on Electronic ignition Module. You already have the double field alt, just need the right regulator, reg plug and add one wire up to the extra prong on alt.

[Ghoste]

For a 69, it is correct to have one brown coming into the ballast and one dark blue going to the coil.  There is another dark blue on the other side of the ballast that goes to the regulator.  That looks like an aftermarket regulator on there, is it already an electronic maybe? 

[mauibarber]

I traced the brown wire by the alternator and that is in fact for the windshield pump, Thanks. 

The alternator was charging fine for the first 8 months but now its not showing more than 12.6 across the battery at 2000 rpm.
I took it to checker and there machine said it had a bad diode.  So I will have it rebuilt.

The voltage regulator could be electronic I suppose?  Is there any way of telling from the outside?

And finally, could not grounding the second field terminal fry my diodes on the alternator? If the alternator was charging using only one field connection,  what possible problems could not grouding the second field?

-Alex

[Nacho-RT74]

if is electronic, it is a replacement old fashion electronic upgraded, not the lates electronic unit

If wasn't grounded HOW THE HELL WAS WORKING ? being double field and only one brush feeded . You can not fry a diode if alt is not being feeded.

Who made the conections ? are you sure the second field is not grounded with a metallic washer on retaining screw ?

[mauibarber]

I wanted to give a little update.

It appears the way my alternator is wired up is as follows.  From the bat connection on the alternator are two wires.  One wire is black and goes directly into the left side of the voltage regulator (can be seen in the pic below), the other is purple and goes to the bulkhead.

From the one used field position is a green wire that is also going directly to the voltage regulator on the left side. (Can be seen in the pic below)
This leaves one unused field connection.  There are no other wires coming from the alt.  I did use a ground wire on the open field position but it didn't change anything.

Perhaps the black wire comming from the bat connection is grounding the alt?

I took the car to Checker and there little machine said I had a bad diode and a good battery. 

My question is can a bad regulator show up as a bad diode?  I believe the alternator is producing juice, just not enough.  With the electric fans off the voltage across the battery will be 12.5, but it is only 12 with the car off, so some juice is flowing.


Thanks again for all the help.

[mauibarber]

Who made the conections ? are you sure the second field is not grounded with a metallic washer on retaining screw ?

The previous owner hired a auto electrician to do the engine compartment.

I hope I don't sound stupid but to be grounded it would have to atach somewhere correct?  The only thing coming off the field is a metal tab with a screw in it with two very small washers sandwhiched between.  But nothing is touching that screw or tab so I don't know how it could be grounded. 

[Rolling_Thunder]

As far as I know the large black wire coming off the "batt" terminal on the alternator should be going to the bulkhead connector... 

The purple wire off the "batt" terminal on the alternator should go to the horn relay.

The green field wire is positioned correctly

The second field on the alternator needs to be grounded


Can you take a picture of your bulkhead connector ?

[Nacho-RT74]

purple wire on engine harness is  water temp sender

[mauibarber]

are you sure the second field is not grounded with a metallic washer on retaining screw ?

Nacho could you explain to me exactly how this method of grouding works?  Better yet any pics of what this looks like?

Wouldn't the metalic washer and screw have to be attached with a grounding wire to a ground?

[Nacho-RT74]

I will explain everything on earliers and later system

Single field alts have 2 brushes just one of them isolated and the other one fits directly on alt housing without prong and isolator. This system gets regulated positive source from regulator being this source the PILOT on magnetic field to create output power, for a while the grounded brush have constant negative. Positive regulated source is feeded by the green wire.

Double field alts are with BOTH BRUSHES isolated. This time the regulator ( electronic laters kind ) regulates NEGATIVE coming from green wire. This is the pilot on magnetic field. Regulator takes negative from chassis on firewall. The positive source comes directly from ignition switch through a blue wire, same wire that feeds, Module, Ballast etc..

Both brushes needs to be isolated because negative is not anymore constant, is regulated, and positive will cause short of course.

The isolation assembly consist on a plastic housing where brush goes in, and isolater washer ( not metallic ) to keep prong isolated from screw what makes contact with chassis.

To make work a double field alt on to a single field system  is enough grounding one of the fields ( anyone ) on two ways, using a terminal and a wire and attaching the wire with a screw somewhere where negative it is. Can be in fact on same alt housing.

I like more the other way what makes a cleaner assembly. Replace the prong/brush isolator washer for a metallic washer to ground the prong, so the brush.