Alternator field wire

[chebba]

What does no voltage on the blue field wire indicate on my alternator? Is there a bypass or workaround to test if this is the reason for no charge going to my house batteries? thanks for any help. I did get the alternator tested and was told it was good. Rewired the harness also. thanks again.

[Spot]

Hi Chebba,
Which make and model alternator?
Do you have schematics for the alternator and boat?
Original or new charging system?
I don't know so much, just know that more details will get you a better answer.

[chebba]

Thanks Spot - Balmar, 100 amp, series 6. Harness has the black, red, brown, blue set of wires. I think there is supposes to be some voltage between the black and blue wire coming from the alternator. I have 0 voltage on the blue wire. Volvo md17c with the slaternator added about 7 years ago by PO. There is some magnetism on alternator with key in "on" position.

[Spot]

Hopefully someone who knows about Balmar alternator and systems can join in.
The website seems pretty good, the link to alternators downloads a PDF file for me: https://balmar.net/operation-manuals/

[chebba]

Thanks again!

[smac999]

Do you have an external regulator? Thst is where the blue power comes from. The balmar are both internal and external capible. If you do not have an external. The blue wire would be disconnected. And you’d need power to the ign wire instead.

[chebba]

Thanks for the reply. Your reply gives me a couple of ideas to check out. I currently have the brown ign. wire (12 vdc) connected and the blue (field) wire connected. In the begginning I wasn't sure if the brown wire was connected so I connected it. I am not getting a charge our of my alternator to either batt. bank. I have the ARS 4 ex. regulator and the Digital Duo installed. The ARS 4 LED sequence is correct for start up. The Digital Duo is irrelevant to me right now. First I'd like to get a charge current to the house bank. I am going to test with the brown wire disconnected and then reconnect it and try with the blue wire disconnected. I am using good RPM's and wait times. Shore power off and disconnected. thanks again.

[smac999]

Originally Posted by chebba

Thanks for the reply. Your reply gives me a couple of ideas to check out. I currently have the brown ign. wire (12 vdc) connected and the blue (field) wire connected. In the begginning I wasn't sure if the brown wire was connected so I connected it. I am not getting a charge our of my alternator to either batt. bank. I have the ARS 4 ex. regulator and the Digital Duo installed. The ARS 4 LED sequence is correct for start up. The Digital Duo is irrelevant to me right now. First I'd like to get a charge current to the house bank. I am going to test with the brown wire disconnected and then reconnect it and try with the blue wire disconnected. I am using good RPM's and wait times. Shore power off and disconnected. thanks again.

You can not connect both. You need to choose internal or external. Some use a Selector switch to use the internal as a backup.

If you disconnect the blue wire coming from the ars and measure no voltage then the reg is an issue.

Though with the blue disconnected. It should be charging with the brown. I wonder if the shop tested the internal, external, or both.

[chebba]

I'll try both ways. my brain is what is fried. I've been trying this for awhile now. Can't get an electrician to my boat. It's high season in San Carlos and they're chasing the easy money. If nothing works I'll rest tomorrow and take the alternator into the shop Mon. morn. I try very hard to not do any harm.

[Cheechako]

When a need for charge is sensed, the field activating wire from the Regulator should show voltage. ie: the regulator senses the battery is not charged and sends voltage to the field of the alternator. If you have no voltage on the field wire then nothing is telling your alternator to start charging.
In theory you can connect a battery wire direct to your field and the alternator will charge at maximum output (until it burns up!)

[chebba]

Thank You Cheechako.

[belizesailor]

Originally Posted by Cheechako

When a need for charge is sensed, the field activating wire from the Regulator should show voltage. ie: the regulator senses the battery is not charged and sends voltage to the field of the alternator. If you have no voltage on the field wire then nothing is telling your alternator to start charging.
In theory you can connect a battery wire direct to your field and the alternator will charge at maximum output (until it burns up!)

You can do this very briefly as a test. Its a simple way to field test whether the problem is your alternator or not.

[CharlieJ]

@chebba
There is an excellent, step by step, troubleshooting guide in the Balmar manual referenced up thread. It will help you locate your problem.

[chebba]

Thank you All. tis a pity to be stuck at the dock!!!!!!!

[wsmurdoch]

The previously given Balmar link does not include your ARS-4 regulator. This link does. As CharlieJ said Balmar has excellent troubleshooting guides. https://balmar.net/manuals-for-discontinued-products/ The pre-2005 alternators are there as well.