The Stovebolt Site Forums The Shop Area The Electrical Bay 6 v alternator

hello, i have a 1942 chevrolet truck, a fire engine( i am from a fire department) and the truck is not charging the battery. i did all the tests to determine the alternator isnt working. i plan to keep this 6 volt and want to have the alternator re-wound. i also want to replace the voltage regulator, is this something available at an autoparts store. also, its from leece neville( same as alternator) what else should i be looking for. do i have negative or positive ground system. thanks
michael.

welcome to the garage gocart, there's a buncha firefighters and firetrucks here

if the 42 does have an externally regulated alternator rather than a generator, it's a modification .... yer best bet would be to talk to a good local auto-electric shop, who'd know about the regulator if they can handle a 6v alternator

one thing you might consider is getting the shop to make up an internally regulated 6v alternator, which I had done for a 46, that eliminates the regulator problem and cheaper than both

if the Chev hasn't had other odd changes, it'll be neg ground, the GMCs had pos

Bill

Gocart879,

Welcome to the Stovebolt. Unless your fire engine has been updated, your 'dynamo' would actually be a generator as opposed to a alternator. This would be the first task..properly ID what you have.

To my knowledge, Chevrolet never made a positive ground system. A basic test would be to look at the battery posts. The positive post is usually larger than the negative post, and should go to the starter.

Fire engines sometimes have strange things on them to support extra lights etc. I would take a look at some of the online specialty suppliers like Chev's of the 40's, Jim Carter and the site sponsor, American Classic.

Look at the pictures of the parts they call out for that year rig and see if they correspond to what you have on the engine.

Note the prices of these items, then compare them to what is available locally...sometimes the suppliers beat local prices, and stock the hard to find items.

When you search for parts, ID the rig by year and engine size...leave out the fire engine part!

A generator is pretty bullet proof. Unless it has thrown solder, actually burned up or shorted a winding, it can be rebuilt for not much $$$.

Regulators are available too. I don't know if the '42 has the funny regulator or cutout attached to the generator, but these should be available as well.

More dope will be forthcoming, welcome and enjoy the site.

Stuart

It would have been possible for the truck to have had an alternating current generator with selenium rectifiers from new. The word alternator hadn't been invented yet, I believe.

I,m with Baldy. Some emergency vehicles had A/C generators back before alternators & diods were common. Look for a large layer of plates.

Well, the electrical system was rebuilt in the mid 80's. It has a six volt alternator on it, built by the leece-neville company of ohio. It also has a rectifier on it, assuming that changes from ac to dc current? it has multiple wires coming out of the alternator, maybe six total. 3 leads to the recitifier, and one major ground i think, and 2 small wires not sure what they do. its a big alternator and i will take a pic if some of you want me to. an i can do the electrical system pics to.

these are the folks ya need to talk to concerning the whole setup, you won't find anything at yer local jobber outside special order

Bill

Gocart879,

WOW..fire engine stuff, weird and pricey. Some unsolicited and unprofessional observations.

If you treat this as a alternator with external regulator, you will have to figure out how to put the alternator into full field charge manually to prove it works and put the blame on the regulator or maybe those 'strange two wires'.

The rectifier is external and probably isn't contributing to the no charge situation. The fact that is a very expensive 6 volt alternator doesn't mean it 'tests' any different than a 12 volt externally regulated unit.

A internally regulated alternator is put into full field charge by inserting a small pin/nail/paperclip into a hole in the case to tell the regulator to 'do its thing' with vigor.

I have NO clue how you full field charge test a setup like yours. Maybe you do know how, and have done it. Without being confused by all the extra 'fire engine stuff', the fact remains that it is either being told to charge, and can't..or it isn't being told to charge.

Have you thought about a auto electric shop for some help or guidance.

Stuart

they make 6 volt alternators for tracktors i see them on e bay all the time there only 50 bucks would bolt right up with the right pully and can be pos. or neg. ground

Well, I'm not exactly sure how the unit is tested either, aside from hooking an Impact wrench to the pulley and testing that way, i'm clueless. I am sure the voltage regulator is at fault as well, however i want to make sure the alternator isn't shot first. I would like to test the unit asap. anyone have any ideas, why does this alternator have 3 main wires coming off the top of the unit? and the truck is negative ground. anyone know how to adjust a leece neville volt. regulator? or have a good link to instructions. my fear is the volt regulator was fried from someone jumping the truck with 12 volts, and then the volt regulator fried the alternator too.

Gocart879,

My suggestion still stands about help from a qualified auto electric man. If you are bound and determined to test 'something' here is a recipe from my Motors manual for Leece-Neville alternators...no guarantees!

As with all alternators, the field must be 'excited' for the unit to start charging. Basically, if you turn the key on , engine off , and pull the field wire off the regulator, then 'scratch' or strike that same regulator terminal with the wire, it should show a medium spark. This means the circuit in the regulator is closed and power is available to excite the alternator.

Turn the key off and replace the wire. To put the alternator into full field charge, with everything turned off, pull the field wire (F) from the alternator and hook a jumper from that F terminal that you will momentarily touch to the BATT terminal of the alternator.

If you start the truck (fire engine), and touch that jumper to the BATT terminal, the alternator should go into full charge. You will need a functioning ammeter, or a test voltmeter to see this happen. If this does happen, it tells you your alternator is capable of charging.

This of course would point the guilty finger somewhere else.

I am not sure where a impact wrench comes into the test picture, but if this is a skill level indicator, it might be cheaper to take the old girl to a proper Dr.

Good luck and don't let the magic smoke out!

Stuart

by using an impact gun to slowly spin the pully on the front, i can hook a volt meter to the leads on the back of the alt and see if it generates current. the alt is already out of the rig, and on my workbench at home. so its disconected.

The other day, I was reading up on this company that I found listed in the Tech Tips. I think that they would be worth checking out. They claim to produce 6 volt alternators especially for antique vehicles, that should be better than most others that are available.

I was impressed by what I read about them. See the link below.

http://www.fifthaveinternetgarage.com/

If you give them a try, I would be interested in your results.

Good Luck

John

Gocart879,

Keep in mind that the alternator needs a external voltage source to initiate the charging process. Just spinning the thing on the bench with a impact won't get any results.

Stuart

Well, for those of you who were unclear about it, I contacted Leece-neville Directly, and It is a 7 volt(6 volt) 60amp, 400watt Alternator, the model number is 5084-GA3. Manufactured sometime around 1952, but not installed on this truck until somewhere around 1976. I have sent the unit to a local harkness shop where it will undergo testing, as for now, the shop teacher(he rebuilds and tests 6 volt generators and alternators) says the bearing is shot and could be part of the problem.
Thanks to everyone for your helpand support, i will let you know how it turns out!

Gocart

It sounds like you have a center tap alternator with a full wave rectifier.. I would be careful on how you have rebuild it. the alternator is a 12 volt with a center tap witch gives you +6V and -6V all the time with is a vary affective way wan using an external rectifier. Hard to rebuild if you need to rewind.

Now get this, I was doing some research on the web about ammeters, This rig has an added on leece-neville ammeter, it is hooked up to a small junction block on the firewall(not the voltage reg either) and it doesnt move or do a dam thing when you put lights on or anything, but the one in the dash(factory) will show a large discharge when i turn the lights on. I am assuming that this added on ammeter was working correctly when first installed. is it possible this ammeter burned out and is keeping the truck from charging correctly? it is in series and that would be like the christmas lights, if something goes out, they all turn off. am i making a good assumption? how would i go about testing this ammeter?

Gocart869,

The system on your rig seems quite complicated, and it will be hard to draw conclusions until your alternator is proven to be functioning and reinstalled.

A ammeter is a measure of the current being used by the system and should have no bearing on the ability of the alternator to charge.

Ammeters rarely fail, but when they do, they burn up internally and don't allow current to pass. This would be evident. If this meter inside the engine compartment is indeed in series with a dash mounted unit, then it should read the same exact value as the other gauge.

I would bet that this ammeter might be for another circuit that isn't obvious and isn't being drawn off when you turn on the lights etc.

If you get the charging system repaired and electrically protected so it cannot kill itself, then, with some investigation and a meter you can dissect how this thing works.

Emergency vehicles can have all sorts of strange things added to them. This Leece-Neville system was a classic aftermarket upgrade for rigs just like yours...lots of lights, sirens and do-dads to cover any contingency when it came to saving a life for dousing a burning building.

Back on the ammeter...I think if you have continuity between both terminals, you have a functioning meter. They are pretty straightforward. Good luck.

Stuart

I did a little more snooping and the info I found indicates the #5084-GA3 is indeed a 12 volt, 125 amp alternator. This would support what 1947RBT noted in his post above.

The Leece-Neville #5884-G3 (different) is a 6 volt unit. The plot thickens.... :confused:

Stuart

That is incorrect. According to the company, they gave me the exact info i explained above. the tag on the unit says six volts. it is not 12. you are reading a parts list from the internet and it is not correct, try calling the company and see what they say. trust me. its not 125 amps either, it is 60.

Gocart879,

Yikes, the plot just thinned out....if you can't trust the 'Internet' who can you trust.

You are right, there is bum stuff online all the time. Your phone call was the way to go. Keep us posted.

Stuart

if it is a center tap it will be listed as a 6V becouse it is well both. but I dont know how to exsplanit with out a wight bord and about 45min just think of it as a modernday alt. cut in 1/2 but you can use both sides.

so while i wait to get this thing back, anyone have a good voltage regulator to buy for it? i dont know what i should replace the current one with. how many amps should i be looking for? thanks

well, i did more investigating and noted that the ammeter(mounted in cab below dash) is connected to a small plate on the firewall. this plate has two large wires connected to it. the first large wire comes from the batt. terminal on the voltage regulator, and the second terminal connects to the top of the starter(positive power). The ammeter has two small wires attached to it only, and the small wires attach to this metal plate as well. with each individual wire being attached below on of the bigger wires. is this metal plate a resistor or something? and i measure current with a voltmeter hook one side of ammeter power to positive side, and ground to a good ground, it shows 6 volts. why doesnt this ammeter in the truck move in any direction. is the gauge at fault?

Gocart879,

I will take a guess. The plate is a 'shunt', and is wired as it should be in series with the alternator output (through the regulator) and the battery connection on top of the starer.

The in-dash ammeter is only taking a sampling of the system activity. This setup would be considered a tad more modern, and a little safer in that the ammeter inside the cab doesn't have to act as a conduit for the entire trucks current flow.

Voltage would be read with a voltmeter. Amperage, or current flow must be read with a ammeter. This must be in series with the load, or a inductive device must be used around a wire.

The ammeter will not move until current flows through it (the shunt).

What values are on the ammeter inside the truck? Some gauges might be -60--0--60+ or -30--0--30+.

The gauge, being on a shunt, might not respond to small amounts of draw, but might respond to a charge of 40 amps...who knows.

I didn't think the truck had the alternator in it, so troubleshooting it now isn't a viable option. The gauge could be stuck...when everything is reinstalled, flick it with a finger and see if it starts working.

Stuart

Has anyone heard of an outfit that actually converts the 6V generator to an alternator? Someone recently told me that they had seen an article in a magazine that claimed to use your 6V generator housing and convert it to an alternator, meaning that from outward appearances it was a generator.

Down2sea - you're talking of the Gener-nator - pretty spendy stealth at 800$

Bill

the values for the ammeter show
(-100, -50, 0, +50, +100.)very large portion of coverage dont you think, maybe it is showing minimal current. I have flicked the gauge and the needle will bounce back and forth and settle to its resting point at 0. oh well. thanks.

Bill,

Thanks for the Gener-nator(Boardwalk)link. That's one big bite for my wallet and one small detail for the '41. Me thinks I'll stick to either the 12V conversion or perhaps install one of 5th Avenue's super 6's

the model number for the voltage regulator is r0013604ra. i will do my best to find somewhere to post pics. of it. for the meantime, anyone have any idea of the voltage or amperage of this unit. and where i may get a replacement?

Gocart879,

That is a Leece-Neville part number. I poked around on their site and found reference to a number close to that one on the Q&A forum.

Stuart

Sears used to sell a 120V Alternator that looked exactly like a GM generator, except they had a double plug outlet on top. We used to bolt them right into our stovebolt six.

What good would a 120V alternator do on a stovebolt? I think it would be hard to maintain the correct RPM for 60 Hertz appliances.

Well, the alternator tested out good after the guy replaced a collector ring of some sort or another, i replaced the alternator in the truck and still get nothing. im looking in depth at the regulator now. it has got to be the problem.

Gocart879,

Without getting too complicated, I think you should hear a "click" from the regulator when the key is turned ON. It might be slight enough that you have to hold your ear to it (the regulator), or hold a screwdriver to it while 'listening' to the other end.

The regulator needs to 'click' a relay closed to feed voltage to the alternator in order for it to charge.

This is a basic requirement for a conventional externally regulated system. As I mentioned before, yours doesn't appear to be conventional, but should still have some of the same basic characteristics.

If this type of system is indigenous to emergency apparatus, maybe checking in with a forum specific to fire engines could be worthwhile.

Stuart

with the cap off the regulator, i am able to hear the click and see a contact point close. this happens everytime the key is turned to the on position. i really believe the regulator is at fault, however it's difficult to take care of a problem when you cant find a replacement for it.

Gocart879,

I know it can be very frustrating. I outlined a simple procedure that will verify the field wire TO the alternator, and how to put the unit into full field charge.

A alternator that doesn't charge can be as simple as a broken wire from regulator to alternator...both units are good, but no charging will take place. These things have to be checked.

You have implied that your system is not conventional. If you could take some good pictures of the alternator and regulator with a simple wiring schematic, cyber-troubleshooting would be much easier.

Don't give up, you are making headway.

Stuart

pok, i have followed your instructions from above, and as far as removing the field terminal from the regulator, i have and i dont get any spark(yes ignition is on) I would like to try the full field test, but i am not capable of doing that because im not sure which terminal on the alternator is the battery terminal,( again remember this has 6 wires coming off of it. i am working on the wiring diagram to post here shortly, and will take pictures, however im still wondering where to post the pics. thanx for your help again. mike

To have power for party in some back road place. Records or guitar amps before all this battery stuff.

ok, well i have very exciting news, i jumpered the bat and gen terminals on the truck and presto, it starting charging. putting out the full 60 amps of power(i did this only for a few seconds at a time) so i now know the regulator is shot for sure.