Generator weak - rebuilder? Do myself?

[lancemb]

Any recommendations?  Big blue (57 Roadmaster) has a weak generator.  Is there a good rebuilder, or should one of these kits do just fine?  I am not sure what typically fails on these but if it's juat brushes then maybe this would be all I need?

 

http://www.classicgenerator.com/GeneratorKits.html

 

I really don't want to spend ridiculous money on it if I don't have to, but it needs to be right!

 

Thanks for any input!

[60FlatTop]

Define "weak".

B

[old-tank]

1 hour ago, 60FlatTop said:

Define "weak".

B

If a bearing, bushing and brushes (less than $20 at NAPA) don't fix it, it will need rebuilt or other parts like armature and fields.

[Matt Harwood]

My guy (a retired heavy truck generator rebuilder) charges me less than $100 for most straightforward rebuilds. I don't think you'll be on the hook for a huge expense even if it needs a full rebuild. There's nothing complex or unfamiliar in there and I suspect that most of the parts are still available. Do it right and don't worry about it.

 

My new favorite expression about trying to do old cars on the cheap: Pay a lot, cry once. Pay a little, cry often.

[lancemb]

2 hours ago, 60FlatTop said:

Define "weak".

B

Just going by ammeter, it drains batttery considerably at idle, charges just barely when cruising.  This led to battery dying over weekend after some local stop and go driving and trying to restart.

 

I put an old rebuilt unit (got lucky on finding this) in my other 57 and it always shows a positive charge, even at idle, and goes way up when accelerating.

[lancemb]

44 minutes ago, Matt Harwood said:

My guy (a retired heavy truck generator rebuilder) charges me less than $100 for most straightforward rebuilds. I don't think you'll be on the hook for a huge expense even if it needs a full rebuild. There's nothing complex or unfamiliar in there and I suspect that most of the parts are still available. Do it right and don't worry about it.

 

My new favorite expression about trying to do old cars on the cheap: Pay a lot, cry once. Pay a little, cry often.

Agreed.  I really don't want to do it twice, but if it was generally known that a basic kit with bearing and brushes takes care of these the vast majority of the time then I'd just try it myself.  If not, I'd just get it fully rebuilt. However, I don't know who offers such a service.

[old-tank]

Just search starter alternator generator repair in your area.

Check your battery first or swap in a know good one; then do the same with the voltage regulator.

[D Yaros]

A post leads me to surmise the generator in question is no longer in place on the car.  If that is a case one should be able to do a visual inspection of the brushes without having to remove any parts.  If there is no carbon material left new brushes and a cleaning of the armature might do wonders for the gen?

[60FlatTop]

Could be the belt or any number of components in the charging system. There is an instrument and test procedure for each. Load test he battery, check the voltage at idle, as well as the belt for glazing and cracks and the pulleys for wear. Even a detached harmonic balance damper could do it on some cars.

 

I don't rebuild starters or generators. We have a good shop with friendly staff and they have never billed close to $100 yet. If I question one or get a new car and come across a spare I just drop it off and let them do it. There is a spare alternator ready to go for the Impala and the Riviera sitting over my tool box now. Those are Murphy's alternators. There is a lot of Murphy's stuff around the garage.

 

One thing to remember is added loads. Once I got a call to check a Rolls 20/25 that pegged the ammeter to full discharge when the brakes were applied. It was diagnosed as a "short". I was alone in another person's shop checking every wire and connection based on their assumption. I couldn't see the brake lights but I saw the meter dive. A few hours later I turned down the lighting ready to go, stepped on the brake and the whole shop lit up. I had not seen there were about six stop lights and another six amber lights all tied to the brake lights. I disconnected one added light, checked the ohmic, plugged it into Ohm's Law, value and multiplied by 10 or 12, whatever number; and got about 20 amps, the limit of the 20/25 charging system and the meter. Now that's an example of anecdotal vs.measured scientific values.

 

Get the other meter out. It's more fun.

Bernie

[lancemb]

3 hours ago, old-tank said:

Just search starter alternator generator repair in your area.

Check your battery first or swap in a know good one; then do the same with the voltage regulator.

I did do a local search and couldn't come up with anything YET.  I did put a new battery in and same issue.  I did NOT check the regulator yet; not a bad idea as I know it is very old.

[Ttotired]

I am an auto electrician (try searching "auto electrician" in your area) and I think it will most likely be out of brushes, but (as said) it could be other things causing it as well, so proper testing should be done and the test (and rebuild procedure) should be in your workshop manual.

 

That said, I have had to repair a lot of stuff after a home repair has been done by someone who did not really understand what had to be done and charging systems are rather unforgiving if you get it wrong

 

Also, be aware that even if the brushes have worn out, that will sometimes "upset" the regulator and it may require resetting as well

 

A proper repair/rebuild should also include the re machining and under cutting of the commutator (part the brushes rub on on the armature) as they wear out of round and as they wear, the insulator between the com bars can end up higher than the bars themselves and the brushes wont contact the bars

 

 

[NTX5467]

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(HOW to delete all of these unintended "quote" fields??  When clicking on the "reply" area, the cursor automatically ends up on the "quote" icon and activates.  No way to inactivate once activated???)

 

Don't forget that the charging circuit goes through the bulkhead connection on the firewall.  Those connections under there can become gunky with time, by observation.

 

Personally, I like Old-Tank's suggestion, considering the approximate cost!  Get one and pay the core charge, if any.  Then rebuild yours when you can.  This would give you a "tested unit" with a warranty (of some kind).  BUT (as you've probably already done) be sure all of the connections for cables and such are CLEAN (not just by looking, but by using a wire brush to clean them).  I found out once that a seemingly minor coating can make a LOT of difference in current flow (or not flowing).  Cables, ground straps, etc.

 

Then also check the points in the regulator.  They are similar to ignition points, in design and might be "corroded" somewhat, affecting the regulator's operation.  In some brands, the "old look" regulator has "electronic guts" inside.

 

Please keep us posted on your progress.

 

NTX5467

Edited June 21, 2016 by NTX5467 (see edit history)

[lancemb]

Thanks for the ideas!  The regulator is cheap enough that I think I will just replace it to eliminate that possibility.  The one on the car is from at least the 1970's and I've been driving the car for about 8 years with it!

 

If that doesn't take care of it, I do have a used generator I could clean up and try.  I think it's okay but not sure.  If it works okay, I'll leave it in until I get the chance to attempt a "light rebuild" on the one that's in there.  If not, I'll find a professional rebuilder somewhere sooner.  The only new/rebuilt ones off the shelf are over $400 and I have no idea of the quality.

 

I will also check the connections along the way.  If I get stuck after some of these quick attempts I'll break out the manual.

 

I'll report back when I make progress.  In the meantime any reputable rebuilder in the Chicago area or elsewhere I can ship to would be an appreciated tip!

Edited June 21, 2016 by lancemb
Typo (see edit history)

[planecrazy]

Look for re-builder that has a Generator test bench and knows how to use it. I think the old "Motors Manuals" has the generator output specs and RPM listed in them. The test should not take more than a few minutes. I would not invest in a bearing and brush kit until I know this. If the output is found to be low you could have a open armature winding or some degree of shorted field winding's. Then the rebuild is necessary. The battery load test was always the first test we did in the shop back in the day, the generator/regulator bench test the second, if no joy found there then the wiring/grounding trouble shooting began. The things listed above like loose or bad belts was quickly checked when we opened the hood to do the battery load and charging system test and could quickly be eliminated.

Best of luck

Bill

Edited June 21, 2016 by planecrazy
spacing (see edit history)

[Barney Eaton]

There is not much you can do to a generator, if the windings are bad you probably cannot "fix" them, they must be replaced.  that leaves cleaning everything and new brushes which would be maybe $10.

(thinking electrically) ......maybe the bearing/bushings are worn but the only hard thing there is getting the pulley off to replace the bearing.    As stated above......check the connections as they can corrode and loosen over time.

[d2_willys]

check the generator by shorting the field terminal on either the generator or regulator to ground. If the ammeter goes up as you rev the engine, the generator is probably good and the regulator might be going bad.

[SpecialEducation]

Sometimes just cleaning it up can help.  As the brushes wear, you can get a trace down the conductive brush dust that creates a leak.
 

Brushes are cheap & easy, I'd start there.

 

Also, don't just buy an off the shelf regulator and assume it's good.  We did that once and still had troubles.  It would run the generator up to 19v, and cut it off at 14.4v.  They don't have the fancy screw adjustments like they used to, you just have to bend the tangs a little to dial them in:

 

https://www.facebook.com/1956Buick/photos/?tab=album&album_id=568738759868333

 

Of course, you could just put a self regulating alternator on there instead.  I have an '83 C10 with a 305 and decided that would be easy enough to adapt, so that's what we asked for at the auto parts store.  Not exactly a drop in, but it wasn't an extensive mod.  Less than $50 for the whole conversion.  One of these days dad will drop the bucks on an alternator that looks like a generator, but for now, it's trouble free and makes way more juice than we will ever need.

I keep waiting for used growlers to get cheap on eBay, but it doesn't look like that will happen anytime soon.  I did pick up a 100A Chinese ammeter for less than $10, though! 

What part of the country are you in, Lance?  When I was living in Oklahoma City, we had C&P rebuild our starter, and they do generators too.  (405) 799-2083

[lancemb]

8 hours ago, SpecialEducation said:

Sometimes just cleaning it up can help.  As the brushes wear, you can get a trace down the conductive brush dust that creates a leak.
 

Brushes are cheap & easy, I'd start there.

 

Also, don't just buy an off the shelf regulator and assume it's good.

 

Of course, you could just put a self regulating alternator on there instead.  I have an '83 C10 with a 305 and decided that would be easy enough to adapt, so that's what we asked for at the auto parts store.  Not exactly a drop in, but it wasn't an extensive mod.  Less than $50 for the whole conversion.  
What part of the country are you in, Lance?  When I was living in Oklahoma City, we had C&P rebuild our starter, and they do generators too.  (405) 799-2083

Thanks, I think I'll try cleaning it up and changing the brushes.  I do want to try the other one I have anyway.  I am thinking it's okay because it's off my convertible which was running and driving, though I didn't really drive it before pulling the engine.  I replaced it since I had a rebuilt one and I already had everything apart.

 

I have an NOS regulator so hoping it's okay.  So, if I swap the generator and regulator and all is well I'll just leave it and be happy until I get a chance to monkey with this generator.  I'm short on time right now so the quickest path to getting Big Blue back on the road is what I'm looking for in the near term.

 

I've considered installing an alternator but I am kind of a stickler for originality to a reasonable extent.  Only modification I've done is electronic ignition.

 

I am in Chicago area.  Does C&P do stuff via mail exchange?  Given my lack of time and expertise in generators that is something I'd farm out for a quality rebuild if I find a good source.  Even if my other one proves to be good I wouldn't mind having another on the shelf that's known good!

[Beemon]

Out of curiosity, are you running Halogen headlight bulbs? If I recall correctly, they are upwards of 150 watts each, a big difference versus the old 50-60 watt bulbs. Each Halogen bulb draws approximately 10 amps each, so your generator could be working just fine. Another thing to consider is any other type of electrical accessory that was not contemporary to the time period (electronic ignition, better radio, electric wipers, etc)

 

 

The first image is just the headlights, the second is the headlights and blower and the third is with the radio turned on. The only thing that is not stock in the electrical charging system is the Halogen bulbs.

 

To put into perspective, I had my generator rebuilt about a year ago now. These readings are at an idle speed of 600 rpm or thereabout. At fast idle, or cruising about 2000 RPMs, it goes to a little above "0", but never towards C. The only time I've ever seen it go up to C is after initial engine startup, where it charges the battery after cranking and before I turn the headlights on. On fast idle cam, I get a healthy charge of around 14 volts, so the generator is working great. Due to unfortunate circumstances, the car has become my daily for the interim and I work nights. I live about 5 stop lights from work and at the fourth stop light, if I hit every red light, the headlights start to flicker and dash lights dim until I get back up to cruising speed.

 

I see you have done electronic ignition, what kind? Depending on the system, it could also be putting a load on your generator.

[Ttotired]

Watts are Watts, dont matter if they are halogen or not, just the halogen gives a better light than the equivalent sealed beam for the same amount of current

Beemon, If your that close to work, I would consider putting your battery on charge every few days for a few hours to just top it up from the sounds of it.

It used to be common practice for this to happen back in the day, especially for the "town" cars

 

 

[lancemb]

Beemon -

I have Pertronix ignition, just to replace the points.  I can't imagine this would place any significant draw.  Everything else is totally stock.  Original T3 headlights even, although I rarely use them.

 

This car has been like you describe forever, where it drains at idle and charges at cruising.  Now, however, it only charges at acceleration, and not by much.

 

My other 57 Roadmaster, with a NORS generator, performs leaps and bounds better.  In fact, I'd question if your charging system is working correctly b

because I don't have the issues you describe with your car with my other 57.  Is your battery big enough?  I know a beefy battery goes a long way in these cars from past experiences.

Thanks for the comparison!

[Beemon]

6 hours ago, Ttotired said:

Watts are Watts, dont matter if they are halogen or not, just the halogen gives a better light than the equivalent sealed beam for the same amount of current

Beemon, If your that close to work, I would consider putting your battery on charge every few days for a few hours to just top it up from the sounds of it.

It used to be common practice for this to happen back in the day, especially for the "town" cars

 

 

 

But the fact that they're larger watt bulbs means they still pull more amps.  P=IV, and the voltage is constant. A stock 60 watt bulb or thereabouts only puts out about a 5 amp draw compared to a 150 watt bulb, which is more than 10 amps. 

 

Anyways I don't mean to get off topic, I was just curious if OP had electrical accessories that put a strain on his system like I did. 

Edited June 29, 2016 by Beemon (see edit history)

[SpecialEducation]

9 hours ago, lancemb said:

I have an NOS regulator so hoping it's okay.  So, if I swap the generator and regulator and all is well I'll just leave it and be happy until I get a chance to monkey with this generator.  I'm short on time right now so the quickest path to getting Big Blue back on the road is what I'm looking for in the near term.

 

Remember that there are 3 components to the regulator:  The cut-out (driver's side on our '56), the current limiter (center), and the voltage regulator (pax).  If any one of these three components is out of adjustment, the whole system goes wonky.  With the cover off and the engine running, the cut-out should be closed, the current limiter should be closed, and the voltage regulator should be dancing.  You can do a quick visual in just a few minutes to see if that's the case.  The current limiter should only open at the maximum current rating of the generator (30A for our '56), and the cut-out should open when you turn the engine off.  I pulled the cover once and saw the cut-out dancing.  No wonder it wasn't charging.

 

9 hours ago, lancemb said:

I've considered installing an alternator but I am kind of a stickler for originality to a reasonable extent.  Only modification I've done is electronic ignition.

 

I admit that it's ugly, but it's functionally awesome.  I can sit at idle with the lights on and get a good amount of charge.  In fact, I can't load it up enough to show a discharge at idle (to be fair, I gutted the Sonomatic and put in a solid state amp, so it draws much less than the tubes did).  For the most part I used existing wires for a more factory look (I put a 30 amp fuse in-line to protect the original wires), and it's completely undoable later if I ever so desire.

 

9 hours ago, lancemb said:

I am in Chicago area.  Does C&P do stuff via mail exchange?  Given my lack of time and expertise in generators that is something I'd farm out for a quality rebuild if I find a good source.  Even if my other one proves to be good I wouldn't mind having another on the shelf that's known good!

 

I'm sure C&P would take care of you, but I'd be surprised if there isn't a shop or 5 in the Chicago area that can get you going, too...

 

[d2_willys]

Another thing is to check the grounds of the generator, regulator, and battery. There should be NO resistance between any of them. If the regulator is not grounded well, then the voltage regulator will not work correctly and give you the issues you are experiencing.

[NTX5467]

The halogen headlights have two differences from the sealed beams.  The halogen light bulb, itself, is a more efficient light producer (with a little whiter "color" or the light).  The other big difference is the beam pattern!  More modern and more defined in where it goes.  All for the same wattage rating!

 

NTX5467

Edited June 30, 2016 by NTX5467 (see edit history)

[lancemb]

OK, I have an update.  I started up Big Blue today and noticed the charge was like it was before the last time I drove it.  Still barely charging, but charging.  This immediately made me think such erratic would likely be the regulator over the generator, so I managed to squeeze enough time to replace the regulator.  I had an NOS remanufactured Delco one on the shelf so I thought I'd give it a try.  As soon as I started it back up, (with engine still pretty cold), the ammeter went damn-near full tilt on the charge side!  Since I was going to pick up dinner, I thought I'd test drive it.  When the engine was fully warmed up and it was idling and in gear, the ammeter still dipped a little on the drain side.  However, with just the slightest touch of gas it started charging, and when cruising was getting a great charge, very much unlike last time I drove it a couple weeks ago.  So, I think I'm good to go and that the old regulator was definitely failing.  However, is it still normal to drain a bit when in gear at idle?

 

Overall a good experience.  I got to use my nifty new old vintage Delco fender cover, and was even able to recover my 7/16 socket that fell into the dark depths of the inner fender support!

[SpecialEducation]

On 7/15/2016 at 9:32 PM, lancemb said:

However, is it still normal to drain a bit when in gear at idle?

 

With headlights on?  Maybe.  With no load?  I don't think so.  Put a volt meter on it and see what the difference is between battery voltage (engine off) and idle voltage.  If idle voltage is higher, the generator is probably doing what it can.  If voltage goes down, that would indicate that the cut-out is preventing field excitement and needs to be tweaked a little.

[Matt Harwood]

On 7/15/2016 at 10:32 PM, lancemb said:

  However, is it still normal to drain a bit when in gear at idle?

 

I think it's normal. I'm not sure on the later cars, but on every one of my pre-war cars, they drop to the discharge side at idle, particularly with the lights on. On both the '41 Buick and the '41 Cadillac, they show about 0 at idle with no lights, maybe a little discharge with the brake lights on (I can make the needle move by pushing the brake pedal). The '41 Cadillac is more pronounced because it's a Hydra-Matic and idles at about 350 RPM when it's in gear, the Buick is pretty impervious to fluctuations except the headlights. Both are 6-volt cars with stock 35 amp generators and new regulators.

Generators don't make low-speed power as well as alternators, which is why most of the industry switched in the early 1960s. Seeing it discharging at idle, especially under load, isn't unusual at all, just as long as it catches up and recharges the battery and returns to 0 when you get rolling again. Totally normal. Someone earlier in the thread mentioned that cars driven frequently in town often had insufficiently charged batteries, and this lack of low-speed charging is why.

Everything should be OK as long as it catches up and eventually returns to 0 after you're at speed again.

[buick5563]

^^^What Matt said.

[lancemb]

Ok thanks for the input

2 hours ago, Matt Harwood said:

 

I think it's normal. I'm not sure on the later cars, but on every one of my pre-war cars, they drop to the discharge side at idle, particularly with the lights on. On both the '41 Buick and the '41 Cadillac, they show about 0 at idle with no lights, maybe a little discharge with the brake lights on (I can make the needle move by pushing the brake pedal). The '41 Cadillac is more pronounced because it's a Hydra-Matic and idles at about 350 RPM when it's in gear, the Buick is pretty impervious to fluctuations except the headlights. Both are 6-volt cars with stock 35 amp generators and new regulators.

Generators don't make low-speed power as well as alternators, which is why most of the industry switched in the early 1960s. Seeing it discharging at idle, especially under load, isn't unusual at all, just as long as it catches up and recharges the battery and returns to 0 when you get rolling again. Totally normal. Someone earlier in the thread mentioned that cars driven frequently in town often had insufficiently charged batteries, and this lack of low-speed charging is why.

Everything should be OK as long as it catches up and eventually returns to 0 after you're at speed again.

OK thanks for the input!  It does start charging quickly with just a slight tap of the gas so I think it should be okay.  I've been driving it for years performing worse than this before changingthe regulator.  I was just curious if it would still gain me much by rebuilding the generator.  I think I'll drive it as is and enjoy it and maybe rebuild the alternator when I have more time!

[Joseph P. Indusi]

Matt said it beautifully.  Right on.

Joe

[old-tank]

 I wish I could be so lucky .  Every time I have a charging failure, I change the regulator...never works then have to do the generator.

[Rosiesdad]

I love my 6v alternator. 

Just sayin......