Testing a cutout

[fred93]

I saw a post that said the way to test a generator cutout was to take the fan belt off and see if the generator starts turning like a motor.

Wouldn't it be easier just to turn off the engine and put a test light to the output wire of the generator. If it lights up then the contact points are stuck together.

With that thought I am thinking that a small indicator light could be connected to the output wire of the generator. If the engine is turned off and the indicator light stays on then you know that the contact points are sticking and you WILL have a dead battery in the morning!

To test the cutout to see if it is working (making contact from the generator to the wires on the outlet side of the cutout you would need a multi-meter that shows DC voltage. The voltage into the cutout will be around 8 volts and it should be about the same on the outlet side of the cutout. If the voltage is way low on the outlet side of the cutout then it is not working.

[rotorwrench]

That would tell you that the points are stuck together but it's risky. The light connected to the output would light up due to the battery connection.

To test for stuck points, you need either an ohms meter to just check for continuity through the cutout or you need to just disconnect (isolate) the generator output terminal from the cut out input terminal and then see if it will light the test light when touching the input terminal of the cut out. It current flows through then the points are stuck closed.

The cutout shouldn't take much more than 6-volts to close the switch when applied to the input terminal. A 6-volt battery set up to operate the cut out should work to close the points as long as there is a ground path connection. A person can momentarily operate it that way but I wouldn't let it stay closed very long. If a 6-volt test lamp is connected to the output side, you can see if it lights up when the cutout closes. A volt meter would work just as well.

One thing that is important though is that a person needs to be sure that the unit is a real cutout switch. A diode is a different thing and a fun projects regulator is too.

[Jacksonlll]

I think your set would work, but the light would be on when the running above idle. Why not just use the ammeter. If it is discharging when you turn off the engine, it is stuck. Easier just to put a new cut out on. Diode or not. We all use 6 volt alternators. Good luck.

[jb-ob]

Jacksonlll

As Tonto would say, "What do you mean We ??"

[Jacksonlll]

Sorry about that. I meant our club members. Kemosabe.

[old31]

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Hi Ho Silver.

Every now and then I watch the show. I enjoy the simplicity.

The fight scenes are terrible, no one ever gets killed, tonto is always the yes man, silver is a cool horse, some of the scenes are shot in a studio, you can hear the echo when they talk, always a great story, the end of the show is always "hey who was that masked man, I never got to thank him", Well don't you know that was the Lone Ranger.

That is truly early TV. Different that shows today.

[Kurt in NJ]

with as stock cutout testing is done with ammeter and voltmeter, --to make it simmple the generator side has to get to or a little above battery voltage to close cutout contacts --6.2-7.5 volts or so when generator comes back to idle--not charging the cutout has to open---this should happen by about 3 amps discharge into the generator, but no sooner than generator voltage equal to battery voltage

with a diode cutout when the generator side gets to about 1/2 volt above battery voltage it "connects", and will remain 1/2 volt above battery side voltage until generator voltage gets less than 1/2 volt above battery ---think of it as a "one way valve"

[rotorwrench]

Diodes will generally pass current as soon as it starts to flow. It just can't go back the other direction. It's like a one way check valve for current/voltage.

Diodes can get hot though and some of these units have no heat sink. If it has a heat sink, it should last longer. Nurex uses one but I don't know how effective it is.

[katy]

When buying a diode cut out be sure to get one of the proper polarity for the vehicle that you plan on putting it on, as they are polarity sensitive.

[Tom Endy]

The attached article may be of help.
Tom Endy

[fred93]

Originally Posted by katy

When buying a diode cut out be sure to get one of the proper polarity for the vehicle that you plan on putting it on, as they are polarity sensitive.

**************************************************
I took the numbers off the one that went bad and found a new one on Amazon.

That should be ok???

The only difference is that the one on Amazon is a 1N1183A and the one in the bad cutout is 1N1183 --Does the "A" make a difference???

[fred93]

Originally Posted by rotorwrench

That would tell you that the points are stuck together but it's risky. The light connected to the output would light up due to the battery connection.

To test for stuck points, you need either an ohms meter to just check for continuity through the cutout or you need to just disconnect (isolate) the generator output terminal from the cut out input terminal and then see if it will light the test light when touching the input terminal of the cut out. It current flows through then the points are stuck closed.

The cutout shouldn't take much more than 6-volts to close the switch when applied to the input terminal. A 6-volt battery set up to operate the cut out should work to close the points as long as there is a ground path connection. A person can momentarily operate it that way but I wouldn't let it stay closed very long. If a 6-volt test lamp is connected to the output side, you can see if it lights up when the cutout closes. A volt meter would work just as well.

One thing that is important though is that a person needs to be sure that the unit is a real cutout switch. A diode is a different thing and a fun projects regulator is too.

**************************************************

What is "Fun Projects Regulator" Can I find it on the web???

Never mind-I found it. Looks like everything is "back ordered". I think I'll pass. I'm tired of buying parts for this car that are junk!

[rotorwrench]

A person has to call them. I don't think they update their web site. John Regan sold the business to the Bird Haven Vintage Auto Supply some time back and I think they have been selling to parts vendors more than the public.

[Ernie Vitucci]

Good Morning....When I need parts, I go to one of two places. I call Bratton's 800-255-1929 or Arizona Model A 480-782-0266. First, both carry the 'good' parts and second, we do need to keep these suppliers in business...They and all the other Model 'A' Suppliers are part of the backbone of the hobby. Ernie in Arizona

[katy]

The only difference is that the one on Amazon is a 1N1183A and the one in the bad cutout is 1N1183 --Does the "A" make a difference???

the 1M1183A should work fine, the A says there is a difference but is not enough to worry about.

From Digi-Key tech expert: The only real differences I see is that the 1183A has a higher current rating and temperature range while having a slightly lower maximum forward voltage than the 1183.

So while there are some small differences between the two, I see nothing that would cause any issues to use the 1183A to replace the 1183. The lower forward voltage could possibly be a minor thing to consider, but the difference is about 0.3V maximum so I doubt it would be of any concern.

[fred93]

Originally Posted by katy

the 1M1183A should work fine, the A says there is a difference but is not enough to worry about.

From Digi-Key tech expert: The only real differences I see is that the 1183A has a higher current rating and temperature range while having a slightly lower maximum forward voltage than the 1183.

So while there are some small differences between the two, I see nothing that would cause any issues to use the 1183A to replace the 1183. The lower forward voltage could possibly be a minor thing to consider, but the difference is about 0.3V maximum so I doubt it would be of any concern.

**********************************************

Thanks for the reply.

One more question at this point--

Why can't I lower the amperage anymore than 10 amps??? I can't move the 3rd brush in the generator any further. Is that a problem??

Want about the voltage reading that I had last time (8.4 volts) is that going to be an issue??

[fred93]

Originally Posted by rotorwrench

A person has to call them. I don't think they update their web site. John Regan sold the business to the Bird Haven Vintage Auto Supply some time back and I think they have been selling to parts vendors more than the public.

******************************************

Will their units regulate voltage AND amps??

[katy]

Why can't I lower the amperage anymore than 10 amps??? I can't move the 3rd brush in the generator any further. Is that a problem??

Maybe the generator has been assembled improperly by a PO?

[QUOTE]Will their units regulate voltage AND amps??/QUOTE]

They will regulate the voltage only. According to their instructions the generator must be set to a maximum of 10 amps.

[katy]

Deleted double post

[Badpuppy]

Originally Posted by fred93

**********************************************

Thanks for the reply.

One more question at this point--

Why can't I lower the amperage anymore than 10 amps??? I can't move the 3rd brush in the generator any further. Is that a problem??

Want about the voltage reading that I had last time (8.4 volts) is that going to be an issue??

Measure battery voltage at the starter post and adjust third brush for 7.2-7.5 volts. If you can't achieve this, either engine speed is too high or something wrong with the gen.

It's normal to show a high recovery charge rate immediately after starting, but should drop to 1 or 2 amps in a short time. (If the coil is connected to the battery side at the junction box, add 5 amps to that.) If the charge rate remains high for more than a minute or two it indicates a highly discharged battery.

A generator produces power - voltage times amperes. With a constant load (amps) the voltage output rides the roller coaster of engine RPM. A voltage regulator maintains a constant voltage output under varying loads and engine speeds, which prevents bulb burnout and battery hydration from overvoltage.

Ideal battery float (charge) voltage is 7.2-7.9V. Your battery will hydrate at 8.4. A battery will also fail if left undercharged for any length of time.

[rotorwrench]

I have a link here that investigates John Regan's regulator design. With the interaction of voltage, current, and resistance, I like to think that the regulator is actually regulating current more than voltage but it really does both at the same time. One for output and one for protection. The battery still regulates the system voltage like any other 3-brush generator. The unit just grounds the output like a very rapid on off switch. A 2-brush generator needs two separate poles to keep voltage and current both in check but it doesn't quite work the same way.
http://members.iinet.net.au/~cool386...regulator.html

The Fun Projects design is known to be vulnerable to battery disconnect when the generator is operational and it is vulnerable to any change of polarity. Fun Projects makes them for positive or negative ground so a person needs to know not to reverse polarity. A person can build their own if they have the where with all. They will drop the output current of the generator as the battery is nearing a full state of charge. This greatly reduces the work it has to do and will increase its life a good bit.

I would have a serious look into the condition of the generator if it can't be adjusted to a lower output current value. It may have a problem with some internal component or it may just have a problem with the adjuster rail.

[Badpuppy]

Thanks for the link, rotorwrench. Now i see how the thing works with no connection to the field winding. Just dumps excess generator output to ground. Sledgehammer approach, imo, but can't deny it works. Tom Wesenberg's design is more elegant, actually interrupts field current when it isn't required. Saves a bit of engine horsepower that way. Unfortunately it looks like Tom's not in the business anymore either.

[fred93]

Originally Posted by Badpuppy

Thanks for the link, rotorwrench. Now i see how the thing works with no connection to the field winding. Just dumps excess generator output to ground. Sledgehammer approach, imo, but can't deny it works. Tom Wesenberg's design is more elegant, actually interrupts field current when it isn't required. Saves a bit of engine horsepower that way. Unfortunately it looks like Tom's not in the business anymore either.

I have been in touch with Tom this past week about my problems with the generator/cutout and ammeter on the 29 Tudor that I have been working on. I asked him about the voltage regulator that he has been selling. He is out of town right now but he said that when he gets back in a couple of weeks he will let me know if he has any units available.

[fred93]

Originally Posted by rotorwrench

I have a link here that investigates John Regan's regulator design. With the interaction of voltage, current, and resistance, I like to think that the regulator is actually regulating current more than voltage but it really does both at the same time. One for output and one for protection. The battery still regulates the system voltage like any other 3-brush generator. The unit just grounds the output like a very rapid on off switch. A 2-brush generator needs two separate poles to keep voltage and current both in check but it doesn't quite work the same way.
http://members.iinet.net.au/~cool386...regulator.html

The Fun Projects design is known to be vulnerable to battery disconnect when the generator is operational and it is vulnerable to any change of polarity. Fun Projects makes them for positive or negative ground so a person needs to know not to reverse polarity. A person can build their own if they have the where with all. They will drop the output current of the generator as the battery is nearing a full state of charge. This greatly reduces the work it has to do and will increase its life a good bit.

I would have a serious look into the condition of the generator if it can't be adjusted to a lower output current value. It may have a problem with some internal component or it may just have a problem with the adjuster rail.

************************************************** ***

Thanks for your reply-

I have removed the generator and took it apart. Somethings were "very interesting" to say the least. Someone has rebuilt this unit not too long before I started working on the car. When I was adjusting the 3rd brush (while it was still on the car) I had to use a screw driver and a hammer to get it to move. So I worked on that problem once I had it on the bench and apart. Now it moves without using a hammer and I can now move it a little further towards to top (thus obtain a lower amperage output. I'll see how that works when I put it back together and get it in the car again.

Whoever rebuilt this painted the inside of the generator with a silver paint. The paint was so thick that I am surprised the the generator worked at all. The incorrect brushes were installed. At least one was incorrect--the 3rd brush is supposed to be thinner than the other two--however they are all of the thicker type.

I was informed that this generator is off a 32 Ford due to the wire coming out of the rear hole on the top of the unit as opposed to a terminal post. The wire inside the generator that comes from the field coils is grounded inside the unit with a screw and nut.That didn't look very clean--so I cleaned that up and installed a new screw, nut and washer.

The brush holder bushings & washers have seen better days--so I will replace them. Also, the 3rd brush retainer springs are not correct for this generator.

I had new front and rear sealed bearings on the shelf, so I figured that I might as well replace them as well.

I will be ordering parts tomorrow so it will be a week or so before I can post results.--Wish me luck!

[rotorwrench]

A lot of stuff was mixed & matched by the auto parts rebuilder sources back in the day. A B model unit is similar but different and I'd be relatively certain that there were aftermarket parts being used during overhaul of some units as well.

You likely did find where at least one of the problems came from. Now it's all about getting your unit to function like it should or perhaps another unit.

[bobbader]

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Your rear plate indicates that this probably IS a Model A Generator. If it's a B generator, the difference is that the rear edge of the case might have a chamfer on it but the rear cover might likely be cast aluminum or a variation of the 31 cast iron plate. The stamped steel cover that you show was used after the 28 Powerhouse generator was discontinued until sometime well into 1930. My guess is you have a Model A generator where a "rebuilder" replaced the stud sticking out the top of the case with a lone wire. This is not an uncommon practice as it is easier and cheaper than installing a new stud with proper wire, insulators and electrical connectors. From a strictly mechanical/electrical perspective, it still functions properly. You said somebody had "rebuilt" this generator just before you got the car. I applaud you giving them the benefit of the doubt. From the looks of things, they "thought" they rebuilt it. Using incorrect brushes (I assume you mean they were mounted incorrectly in the holders or maybe were modified to fit this application), heavy silver paint, etc, etc. does not indicate a knowledgeable rebuild. You are wise to be going through it so thoroughly. You've already remedied the "immovable" brush scenario. That's a big plus.

Good luck. You're on the right track. Bob Bader