Community Forums

Bilito · 02-26-2012, 05:00 PM

My alternator is good I had it checked at an auto electric shop, but I am not getting a charge.

I see a box under the hood that looks like a voltage regulator from back in the 60's or 70's. I thought that alternators had the VR built into them.

I cannot find a fuse anywhere for the alternator, any ideas?

autofish · 02-26-2012, 07:02 PM

What type of unit is it this would help us help you. If the alt. only has one large terminal then it has an internal vr but if there are other wires going to it it may be external rv.

Bilito · 02-26-2012, 08:58 PM

Quote:

Originally Posted by autofish

What type of unit is it this would help us help you. If the alt. only has one large terminal then it has an internal vr but if there are other wires going to it it may be external rv.

The alternator has one plug in , I did not count how many wires were in the plug and one bolt on wire

DannyB1954 · 02-26-2012, 09:29 PM

Sounds like you have an external voltage regulator. The other plug in for the alternator most likely has two wires in it. It may also be marked with an F, (for field terminal). There are at least two types of voltage regulators, one varies the voltage to the field terminal, the other type varies the ground side of that field circuit.
You need to get the one made for your vehicle. If you find it and take it off, the same shop that tested your alternator should be able to test the voltage regulator as well. Some applications used a fusible link type of wire to connect the alternator. See if the heavy wire connecting the alternator to the car seems to be solid along it's path.

If you have a volt meter, let me know, and I can perhaps help you further.

Dave78Chief · 02-27-2012, 08:19 AM

Yes you have a external regulator. Most likely mounted under the hood on passenger side close to ignition module. Be sure and check fusible links. Last one I worked on with this problem a fusible link was bad. There are 2 of them in the charging circuit. Schematic drawing is on pdf page 328 of the manual. Harness layout is on pdf page 320 of the manual. The manual RsFlight pointed you to in an earlier thread: http://www.irv2.com/forums/f65/how-t...ml#post1080039

Dave

Bilito · 02-27-2012, 12:41 PM

Quote:

Originally Posted by Dave78Chief

Yes you have a external regulator. Most likely mounted under the hood on passenger side close to ignition module. Be sure and check fusible links. Last one I worked on with this problem a fusible link was bad. There are 2 of them in the charging circuit. Schematic drawing is on pdf page 328 of the manual. Harness layout is on pdf page 320 of the manual. The manual RsFlight pointed you to in an earlier thread: http://www.irv2.com/forums/f65/how-t...ml#post1080039

Dave

I found both the ignition module and the voltage regulator and I have downloaded that manual. The Voltage regulator has one large plug with four wires, a red, a green and two blue, one of the blue is a plug that is not connected to anything and it is hot when I turn the battery disconnect switch on

Dave78Chief · 02-28-2012, 06:59 AM

Wire colors are different then what is on the schematic so, are the wires connected to the regulator in the same manner as the schematic?

You would have voltage at the regulator "A" terminal with the chassis battery connected. It's the "sense" terminal that the regulator uses to maintain the output at approximately 14.1VDC when the engine is running. This is the same voltage at the BAT terminal on the alternator also. As loads on the system increase (additional current needed) the system voltage will drop. Regulator senses this voltage drop and increases the alternator current output to bring the voltage back up to approximately 14.1VDC. The extra lead with nothing connected to it is used for the attachment of a radio noise suppression capacitor if needed. You can purchase universal ones at the auto supply if you have excess noise in the radio.

You will have voltage at the regulator "S" terminal when the ignition switch is ON. Powers up regulator.

Regulator "F" terminal is the low level supply signal to the FLD terminal on the alternator. Used to control the alternator voltage and current output. This is a pulsed type signal which you really cannot measure accurately with a voltmeter.

Alternator STA terminal is only used for the choke. Will only affect charging system if the choke is shorted out. However, there is fusible link in the line so if the choke does short out it should blow.

Are you saying you have a battery disconnect switch on the chassis battery? Typically only used on a diesel but there is no reason for a gas not to have one. Just asking to confirm you are not talking about the Coach battery disconnect switch. If you are talking about the coach battery disconnect (not chassis battery disconnect), then you have an open between the chassis battery and the regulator.

Dave

Bilito · 02-29-2012, 05:45 AM

Quote:

Originally Posted by Dave78Chief

Wire colors are different then what is on the schematic so, are the wires connected to the regulator in the same manner as the schematic?

You would have voltage at the regulator "A" terminal with the chassis battery connected. It's the "sense" terminal that the regulator uses to maintain the output at approximately 14.1VDC when the engine is running. This is the same voltage at the BAT terminal on the alternator also. As loads on the system increase (additional current needed) the system voltage will drop. Regulator senses this voltage drop and increases the alternator current output to bring the voltage back up to approximately 14.1VDC. The extra lead with nothing connected to it is used for the attachment of a radio noise suppression capacitor if needed. You can purchase universal ones at the auto supply if you have excess noise in the radio.

You will have voltage at the regulator "S" terminal when the ignition switch is ON. Powers up regulator.

Regulator "F" terminal is the low level supply signal to the FLD terminal on the alternator. Used to control the alternator voltage and current output. This is a pulsed type signal which you really cannot measure accurately with a voltmeter.

Alternator STA terminal is only used for the choke. Will only affect charging system if the choke is shorted out. However, there is fusible link in the line so if the choke does short out it should blow.

Are you saying you have a battery disconnect switch on the chassis battery? Typically only used on a diesel but there is no reason for a gas not to have one. Just asking to confirm you are not talking about the Coach battery disconnect switch. If you are talking about the coach battery disconnect (not chassis battery disconnect), then you have an open between the chassis battery and the regulator.

Dave

This is all helpful. I have no voltage at all at the connection to the electric choke, are you saying that the STA terminal sends power to the choke?

I have a dual battery disconnect system at the entry door to the RV, it turns the coach batteries and the chassis battery on and off and will also read the voltage of either.

With your help I can take baby steps to fix this charging problem

Can I test the choke by just connecting it to the battery with a jumper to see if it will heat up and open? That should tell me if the choke works OK.
Should that wire from the STA terminal go directly to the choke

Dave78Chief · 02-29-2012, 08:03 AM

Voltage to choke is only available when the engine is running and the alternator is working properly. Do not worry about the choke until you get the main system working. You can disconnect it if you want until the main system is working. The choke is nothing more than a resistive heater element that causes a bimetal strip to expand and contract.

Here is a simplified schematic of the Ford 1G Alternator system (external regulator) when a Amp Meter is used:

As you can see, there is actually not much to it. However, bad connections cause high resistance and voltage drop which fool the regulator into responding improperly. Rather than though parts at this, places like Autozone can normally test the Regulator also. Call the place that tested the Alternator and see if they can test the regulator also. If not, call around and find a place that can.

One thing to note: with electricity, you can turn a circuit ON and it can appear to have voltage at a point (ie: regulator terminal "A") when no current is running through the system. However, once you ask it to flow current, the voltage will drop dramatically due to a corroded connection. So, something can appear good when stagnent but is actually bad. This is why I also use a clamp on DC ampmeter for testing that allows me to see more than just voltage. This meter from Sears (http://www.sears.com/craftsman-digit...p-03482369000P) is the cheapest you will find for a DC clamp on meter. Be careful, most clamp on meters are AC only and you have to make sure you get one that can do both AC and DC.

Your Chassis Battery Disconnect solinoid would be between the battery and the starter relay connection.

If you have a idiot light rather than a gauge let me know as the circuit is different for an idiot light.

Dave

Bilito · 02-29-2012, 09:01 AM

Quote:

Originally Posted by Dave78Chief

Voltage to choke is only available when the engine is running and the alternator is working properly. Do not worry about the choke until you get the main system working. You can disconnect it if you want until the main system is working. The choke is nothing more than a resistive heater element that causes a bimetal strip to expand and contract.

Here is a simplified schematic of the Ford 1G Alternator system (external regulator) when a Amp Meter is used:

As you can see, there is actually not much to it. However, bad connections cause high resistance and voltage drop which fool the regulator into responding improperly. Rather than though parts at this, places like Autozone can normally test the Regulator also. Call the place that tested the Alternator and see if they can test the regulator also. If not, call around and find a place that can.

One thing to note: with electricity, you can turn a circuit ON and it can appear to have voltage at a point (ie: regulator terminal "A") when no current is running through the system. However, once you ask it to flow current, the voltage will drop dramatically due to a corroded connection. So, something can appear good when stagnent but is actually bad. This is why I also use a clamp on DC ampmeter for testing that allows me to see more than just voltage. This meter from Sears (Sears: Online department store featuring appliances, tools, fitness equipment and more) is the cheapest you will find for a DC clamp on meter. Be careful, most clamp on meters are AC only and you have to make sure you get one that can do both AC and DC.

Your Chassis Battery Disconnect solinoid would be between the battery and the starter relay connection.

If you have a idiot light rather than a gauge let me know as the circuit is different for an idiot light.

Dave

thank you very much
Now this is a wire diagram that I can understand, I am gonna check around and see who can test the regulator

Dave78Chief · 02-29-2012, 10:21 AM

LOL - like I said simplified. It only removes some of the details that are on pdf page 328 of the manual. Any of those connectors and fusible links could be real source of your problem. One I worked on the problem was the main fusible link off the starter relay. Only out ward clue was it was real flimsy and spongy feeling however only a couple of strands of wire remained intact. Acted like a large resistance drastically reducing current flow to/from the battery. That high resistance also made the regulator think the battery was charged because it could not see the true battery condition. When the engine was running, the alternator was supplying the load so it did not affect the rig but the battery would not get charged properly.

Dave

Bilito · 02-29-2012, 01:50 PM

Quote:

Originally Posted by Dave78Chief

LOL - like I said simplified. It only removes some of the details that are on pdf page 328 of the manual. Any of those connectors and fusible links could be real source of your problem. One I worked on the problem was the main fusible link off the starter relay. Only out ward clue was it was real flimsy and spongy feeling however only a couple of strands of wire remained intact. Acted like a large resistance drastically reducing current flow to/from the battery. That high resistance also made the regulator think the battery was charged because it could not see the true battery condition. When the engine was running, the alternator was supplying the load so it did not affect the rig but the battery would not get charged properly.

Dave

Problem solved, almost, I pulled the regulator and when I turned it over all theb prongs were full of rust and when I removed the clip in plug one of the prongs came off with it.

Bought a new ac/delco regulator, cleaned all the clip terminals and installed it, started the motor and YES it is charging, but way too much, over 15 volts almost 16, what do I do now

Dave78Chief · 02-29-2012, 02:31 PM

Still have a corroded connector problem some place. Regulator is not seeing the battery voltage correctly so it is telling the alternator to put out to much voltage. Make sure regulator has a good ground. Heading home from work, will be back later.

Dave

Dave78Chief · 02-29-2012, 06:47 PM

Was the 15-16VDC reading up at the alternator or at the battery itself? Read level at battery. Comparing voltage between alternator BAT terminal and across battery terminals to see if there is a bad connection in between.

The condition of the regulator gives you a indication of potential problems. While it is a pain to check connectors and such, it will be something you need to do. Ensure you check:

Terminals for regulator connector wires

Terminals at Alternator

Connections going back to Ignition switch. Hopefully the harness diagram on pdf page 320 will assist you in finding the connectors listed on pdf page 328. If I remember correctly you replaced the Ignition Switch.

Terminal ends at Starter relay, battery disconnect solinoid, and the battery terminals themselves.

Measure across Battery Disconnect Solinoid (yes, one lead meter lead on each large post). Should be less then 1 volt but new solinoid will be almost 0 volt.

As a stated, the corroded condition of the regulator is telling you there may be other problems hidding in the electric system. A Dremel tool, contact cleaner (radio shack), and electrical tape may become your friends.

A fusible link is nothing more than a short piece of wire that is a smaller gauge than the circuit wire. Idea is that if there is to much current draw it will open up. Because of the smaller gauge, they have a habit of degrading with time due to heat generated from the current. Represented as item 37 on pdf page 320. They typically have a flag (ie: 1/2" x 1") on them listing size.

Dave