Go Back  ClassicOldsmobile.com > Repair & Restoration > Electrical
Gen Light | Alternator Smoke | Black Residue on Alt Bracket? >

Gen Light | Alternator Smoke | Black Residue on Alt Bracket?

Gen Light | Alternator Smoke | Black Residue on Alt Bracket?

Old June 8th, 2019, 10:03 AM
  #1  
Registered User
Thread Starter
 
Join Date: Jun 2019
Posts: 5
Cool Gen Light | Alternator Smoke | Black Residue on Alt Bracket?

Hey guys,

I'm brand new to the Oldsmobile world. My dad recently purchased a 1960 Oldsmobile Super 88 with the rocket 394. I have to say I love the vehicle, but she's old and smoky so I've been trying to fix small things here and there to get her running smooth. I am relatively new to restoring vehicles, but I have been tinkering with my 68 F100 for about a year now so I'm getting better each day.

I recently took the car out for a drive at night and noticed that when I got to my destination the GEN light was lit up constantly when I turned my vehicle off. I have quite a bit of blow by and I saw small smoke fumes coming from my hood so I wasn't really alarmed, but I figured I'd take a look anyway. I popped the hood and saw that the alternator was smoking and it smelt quite bad. I also noticed some shiny black residue on the bracket near the belt (belt was fine). There was no residue anywhere else. No oil leaks nothing. I didn't want the battery to die with the light on so I took off my ground. As I put my ground back on it sparked against the terminal and it left quite a burn mark. I've seen small sparks and they are fine, but this seemed quite excessive. I started the car after about an hour, started without any issues drove her home and whenever I put my foot down on the accelerator the light faded on again. Got home light was on disconnected the battery and called it a night.

I am no sure what kind of alternator it is but it looks similar to those big powermaster powergen alternators (its black).

I'm quite new to all of this and still searching through the forum posts for alternator issues, but if anyone know what is going on here any info would greatly be appreciated! All I could find online was maybe something was shorting out.

Thanks in advance!

Raj
crazzmc is offline  
Old June 8th, 2019, 02:52 PM
  #2  
Running On Empty
 
Vintage Chief's Avatar
 
Join Date: Jul 2018
Location: Crystal Coast, NC
Posts: 1,424
Without involving a great deal of detail & additional troubleshooting I'd initially be suspicious the alternator diode(s) is/are bad. Stop by an AutoZone or O'Reilly's auto store, etc. - they'll bring out a tester to check your alternator diode(s) for free and let you know the state of your alternator. Takes about 5-10 minutes.
Vintage Chief is online now  
Old June 8th, 2019, 04:26 PM
  #3  
Registered User
 
OLDSter Ralph's Avatar
 
Join Date: Sep 2017
Location: St. Paul Minnesota
Posts: 1,175
1. Make sure you have an alternator. Since its "black", I am wondering if in fact its a generator and NOT an alternator. I don't recall what year Oldsmobile changed from generators to alternators. A pic would be nice. Charlie Jones or one of the knowledgeable folks will chime in.
2. FYI, 1960 also offered a 371 low compression motor. They were 2 barrels and greenish aqua colored.
OLDSter Ralph is offline  
Old June 9th, 2019, 10:02 AM
  #4  
Registered User
Thread Starter
 
Join Date: Jun 2019
Posts: 5
Originally Posted by OLDSter Ralph View Post
1. Make sure you have an alternator. Since its "black", I am wondering if in fact its a generator and NOT an alternator. I don't recall what year Oldsmobile changed from generators to alternators. A pic would be nice. Charlie Jones or one of the knowledgeable folks will chime in.
2. FYI, 1960 also offered a 371 low compression motor. They were 2 barrels and greenish aqua colored.
I think it could be a Generator. From what I know this car is a really old resto/original. I've attached a few pictures below.

Originally Posted by Vintage Chief View Post
Without involving a great deal of detail & additional troubleshooting I'd initially be suspicious the alternator diode(s) is/are bad. Stop by an AutoZone or O'Reilly's auto store, etc. - they'll bring out a tester to check your alternator diode(s) for free and let you know the state of your alternator. Takes about 5-10 minutes.
I connected a Volt meter to the battery and it was sitting at 12.6 volts. Then I checked one of the points on the Gen/Alt and it was at 14.5. So It might be working, but I'm not sure why it still acted up the other night.







crazzmc is offline  
Old June 9th, 2019, 11:27 AM
  #5  
Running On Empty
 
Vintage Chief's Avatar
 
Join Date: Jul 2018
Location: Crystal Coast, NC
Posts: 1,424
I'm shooting from the hip here, but it's possible a brush or both brushes (I believe there are x2) are going bad or have gone bad. Electrical devices (such as a gen/alt) can intermittently operate when the brushes start going bad. I keep a stock of new spare brushes for various devices (Hitachi Paint Shaver, starters, generators, etc.). The brushes are easy to replace and brushes most certainly do go bad on generators/alternators - it's something you could easily perform yourself.

Here is the listing for the brushes for your 1960 gen/alt on RockAuto.
https://www.rockauto.com/en/catalog/...tor+brush,2424

Here is a super easy to follow diagram of demonstrating the basics of an automobile generator/alternator. The brushes ride over the commutator and are held in via a light gauge spring.

http://www.secondchancegarage.com/public/91.cfm

You can often get to a point where the gen/alt sometimes functions, other times doesn't function, or quits all together. An often tell-tale sign of brushes going bad is when they wear, if they don't wear evenly (lop-sided wear), the spring puts too much pressure on one side of the brush, and the brush is only 1/2 in place, 1/4 in place, the brush is completely worn down, broken, or even the wire itself which commutes the amperage/voltage gets fried. But, changing out brushes is so simple and so inexpensive I'd suggest you simply open up the brush ports, review the brushes for integrity and see if they need replacement.

Last edited by Vintage Chief; June 9th, 2019 at 11:34 AM.
Vintage Chief is online now  
Old June 9th, 2019, 11:46 AM
  #6  
CH3NO2 LEARN IT BURN IT
 
droldsmorland's Avatar
 
Join Date: Jul 2010
Location: Land of Taxes
Posts: 3,176
That's a generator. Check its connections. Could be ready for a rebuild. Could be bad bearings if it's charging ok. Probably has never been oiled. See the oiler caps.
Pull the belts and spin it. Feel the bearings. Should spin easy and smooth.
The gen light indicates energy is going to ground somewhere in the charging system. The bulb wont light if both sides of it are equal. By measuring either side of the feed to the bulb you can figure out which direction to look.
CLEAN ALL GROUNDS...Grounds Grounds Grounds. Every one you can get your hands on. 60 year old the grounds are likely not great, resto or not.
Battery neg should be clean and tight on both ends. same for the positive. If the batt cables OHM out ok and look OK use them otherwise replace with the same size. Don't buy chineasium cheapos! Fusick might have them.
Shouldn't have any sparking going on like that. My guess is the bridge diode is shorted going to ground(don't assume have it tested). Look for a starter generator alternator rebuild house that knows the old stuff. Same deal with the voltage regulator. FInd a solid state unit if they exist? At min send the reg out with the gen so they can be calibrated together.
droldsmorland is offline  
Old June 9th, 2019, 03:34 PM
  #7  
Registered User
Thread Starter
 
Join Date: Jun 2019
Posts: 5
Originally Posted by Vintage Chief View Post
I'm shooting from the hip here, but it's possible a brush or both brushes (I believe there are x2) are going bad or have gone bad. Electrical devices (such as a gen/alt) can intermittently operate when the brushes start going bad. I keep a stock of new spare brushes for various devices (Hitachi Paint Shaver, starters, generators, etc.). The brushes are easy to replace and brushes most certainly do go bad on generators/alternators - it's something you could easily perform yourself.

Here is the listing for the brushes for your 1960 gen/alt on RockAuto.
https://www.rockauto.com/en/catalog/...tor+brush,2424

Here is a super easy to follow diagram of demonstrating the basics of an automobile generator/alternator. The brushes ride over the commutator and are held in via a light gauge spring.

http://www.secondchancegarage.com/public/91.cfm

You can often get to a point where the gen/alt sometimes functions, other times doesn't function, or quits all together. An often tell-tale sign of brushes going bad is when they wear, if they don't wear evenly (lop-sided wear), the spring puts too much pressure on one side of the brush, and the brush is only 1/2 in place, 1/4 in place, the brush is completely worn down, broken, or even the wire itself which commutes the amperage/voltage gets fried. But, changing out brushes is so simple and so inexpensive I'd suggest you simply open up the brush ports, review the brushes for integrity and see if they need replacement.
Thanks I'll take a look.

Originally Posted by droldsmorland View Post
That's a generator. Check its connections. Could be ready for a rebuild. Could be bad bearings if it's charging ok. Probably has never been oiled. See the oiler caps.
Pull the belts and spin it. Feel the bearings. Should spin easy and smooth.
The gen light indicates energy is going to ground somewhere in the charging system. The bulb wont light if both sides of it are equal. By measuring either side of the feed to the bulb you can figure out which direction to look.
CLEAN ALL GROUNDS...Grounds Grounds Grounds. Every one you can get your hands on. 60 year old the grounds are likely not great, resto or not.
Battery neg should be clean and tight on both ends. same for the positive. If the batt cables OHM out ok and look OK use them otherwise replace with the same size. Don't buy chineasium cheapos! Fusick might have them.
Shouldn't have any sparking going on like that. My guess is the bridge diode is shorted going to ground(don't assume have it tested). Look for a starter generator alternator rebuild house that knows the old stuff. Same deal with the voltage regulator. FInd a solid state unit if they exist? At min send the reg out with the gen so they can be calibrated together.
I definitely need to run through all the wires and clean them up. They are caked with grime. Do you guys recommend just upgrading to a modern alternator. If so which one? I don't mind spending a little money to make sure the car runs smooth. I'm going to be upgrading the brakes, want to see if I can get some stock AC parts to get that up and running plus I'm going to replacing the water pump, thermostat and the intake. I have quite a bit of smoke and a bad smell whenever I initially accelerate.
crazzmc is offline  
Old June 9th, 2019, 04:38 PM
  #8  
Registered User
 
Join Date: Feb 2009
Location: Pittsburgh Pa.
Posts: 979
It may be time for an alternator. It sounds like the generator is burnt up and the regulator points were sticking. I would recommend an alternator of 55 amps or more. A 10SI or a 12SI. should be fine.
stellar is offline  
Old June 9th, 2019, 04:41 PM
  #9  
Registered User
 
OLDSter Ralph's Avatar
 
Join Date: Sep 2017
Location: St. Paul Minnesota
Posts: 1,175
Originally Posted by crazzmc View Post
I definitely need to run through all the wires and clean them up. They are caked with grime. Do you guys recommend just upgrading to a modern alternator. If so which one? I don't mind spending a little money to make sure the car runs smooth. I'm going to be upgrading the brakes, want to see if I can get some stock AC parts to get that up and running plus I'm going to replacing the water pump, thermostat and the intake. I have quite a bit of smoke and a bad smell whenever I initially accelerate.
1. Take one thing at a time.
2. I think the generator will work fine, unless you add things. Some on here have converted from generators to alternators. I'll let them give you pro's and cons.
3. RockAuto would be a good source for brake parts, thermostats. There is a discount code for RockAuto in the "Stickies" on this site.
4. If the water pump is bad, try to get it rebuilt nearby.
5. Get a compression check on the engine. I am guessing you may need an overhaul. Have you changed oil yet ?
OLDSter Ralph is offline  
Old June 9th, 2019, 11:14 PM
  #10  
Registered User
Thread Starter
 
Join Date: Jun 2019
Posts: 5
Originally Posted by stellar View Post
It may be time for an alternator. It sounds like the generator is burnt up and the regulator points were sticking. I would recommend an alternator of 55 amps or more. A 10SI or a 12SI. should be fine.
Thanks I'll take a look at those!

Originally Posted by OLDSter Ralph View Post
1. Take one thing at a time.
2. I think the generator will work fine, unless you add things. Some on here have converted from generators to alternators. I'll let them give you pro's and cons.
3. RockAuto would be a good source for brake parts, thermostats. There is a discount code for RockAuto in the "Stickies" on this site.
4. If the water pump is bad, try to get it rebuilt nearby.
5. Get a compression check on the engine. I am guessing you may need an overhaul. Have you changed oil yet ?
For sure definitely starting slow. I'm going to pull the plugs, change the oil, do a compression test, check the vacuum readings from the carb port, also do a combustion test just to make sure my gaskets aren't leaking any coolant.

I also wanted to ask about PCV systems. My valve covers have no ports in them so I will need to find covers that'll work (Any recommendations?). I also am new to Edelbrock carbs, but I'm sure there's a port somewhere for a PCV hose.

Allergies have been absolutely killing me that's why I couldn't get any work done today. Hopefully I'll feel better tomorrow and can get you some more updates. Maybe I should switch up the thread to the Engine or Build log section.
crazzmc is offline  
Old June 10th, 2019, 03:41 AM
  #11  
Running On Empty
 
Vintage Chief's Avatar
 
Join Date: Jul 2018
Location: Crystal Coast, NC
Posts: 1,424
Originally Posted by crazzmc View Post
Thanks I'll take a look at those!

For sure definitely starting slow. I'm going to pull the plugs, change the oil, do a compression test, check the vacuum readings from the carb port, also do a combustion test just to make sure my gaskets aren't leaking any coolant.

I also wanted to ask about PCV systems. My valve covers have no ports in them so I will need to find covers that'll work (Any recommendations?). I also am new to Edelbrock carbs, but I'm sure there's a port somewhere for a PCV hose.

Allergies have been absolutely killing me that's why I couldn't get any work done today. Hopefully I'll feel better tomorrow and can get you some more updates. Maybe I should switch up the thread to the Engine or Build log section.
IMO, you'd be better served by addressing & tackling the item identified in this post - which is your alt/gen issue - until it is resolved. When/If you run into another issue, create another post/thread appropriately titled pertaining to the issue you're having in the appropriate section of the CO site. Nothing wrong having multiple posts as long as they're separate issues. You'll generally receive a larger audience of help since CO members review the New Posts and when a new post is created, it becomes highly visible - as opposed to say an Edelbrock carburetor issue buried thirty items down in a different post. Your call, just my opinion.
Vintage Chief is online now  
Old June 10th, 2019, 06:22 AM
  #12  
Registered User
 
Join Date: Feb 2009
Location: Pittsburgh Pa.
Posts: 979
If you change to an alternator, you may need a mounting bracket and possibly an adjusting arm and possibly different belts. It may be easier to repair the generator and replace the regulator. It did work with the original setup for a long time.
stellar is offline  
Old June 10th, 2019, 09:21 AM
  #13  
Registered User
Thread Starter
 
Join Date: Jun 2019
Posts: 5
Originally Posted by Vintage Chief View Post
IMO, you'd be better served by addressing & tackling the item identified in this post - which is your alt/gen issue - until it is resolved. When/If you run into another issue, create another post/thread appropriately titled pertaining to the issue you're having in the appropriate section of the CO site. Nothing wrong having multiple posts as long as they're separate issues. You'll generally receive a larger audience of help since CO members review the New Posts and when a new post is created, it becomes highly visible - as opposed to say an Edelbrock carburetor issue buried thirty items down in a different post. Your call, just my opinion.
Completely agreed. Just wanted to give some background info here about where I stand. Definitely want to fix this issue first.

Originally Posted by stellar View Post
If you change to an alternator, you may need a mounting bracket and possibly an adjusting arm and possibly different belts. It may be easier to repair the generator and replace the regulator. It did work with the original setup for a long time.
Any recommendations on what regulator I would need a 35 or a 45 amp?

I see these 4 on Rockauto

https://www.rockauto.com/en/catalog/...regulator,4884
crazzmc is offline  
Old June 10th, 2019, 02:18 PM
  #14  
Registered User
 
OLDSter Ralph's Avatar
 
Join Date: Sep 2017
Location: St. Paul Minnesota
Posts: 1,175
Originally Posted by crazzmc View Post
For sure definitely starting slow. I'm going to pull the plugs, change the oil, do a compression test, check the vacuum readings from the carb port, also do a combustion test just to make sure my gaskets aren't leaking any coolant.
I suspect you have a tired motor. This could be a whole 'nother subject.

I also wanted to ask about PCV systems. My valve covers have no ports in them so I will need to find covers that'll work (Any recommendations?). I also am new to Edelbrock carbs, but I'm sure there's a port somewhere for a PCV hose.
There is a "draft tube" bolted to the back of the engine block with two bolts. This tube runs down (usually passenger side) and ends below the block/oil pan. This is what they did before PCV systems that started in the early 1960's. That's why you don't have ports on your valve covers.
Edelbrock carbs are not favored by a lot of folks. Where is the original carb ?

Allergies have been absolutely killing me that's why I couldn't get any work done today. Hopefully I'll feel better tomorrow and can get you some more updates. Maybe I should switch up the thread to the Engine or Build log section.
Lets deal with the generator here and make a new thread for other things. I would just put new bearings and brushes in your generator and move on.
OLDSter Ralph is offline  
Old June 10th, 2019, 02:40 PM
  #15  
Running On Empty
 
Vintage Chief's Avatar
 
Join Date: Jul 2018
Location: Crystal Coast, NC
Posts: 1,424
^^x2^^ on generator bearings/bushings & brushes. Those old generators are heavy duty units which can take a beating & there's good reason they sell bushings & brushes for them since those are considered maintenance items. I'll add that once you (at a minimum) remove the covers to R&R the brushes, spray the entire inside of the generator w/ lots of compressed air - do it outdoors, wear a light general mask. The brushes are nothing more than carbon & the worn brushes leave behind carbon filings which get everywhere inside the generator, coating the commutator, armature, copper windings (field) & the diode(s). Or, if you also elect to replace the bearings/bushings, spray the entire inside w/ compressed air. These old gens are so well built, generally the windings, commutator &/or armature don't fail - they're pretty heavy duty. And, of course, as has already been mentioned clean up the wires leading to/from the generator.
Vintage Chief is online now  
Old June 10th, 2019, 04:00 PM
  #16  
Registered User
 
classicmuscle.442's Avatar
 
Join Date: Sep 2012
Location: Water Wonderland MI.
Posts: 1,233
Not unusual for the generator light to come on at idle, should go off when applying throttle. Might pull generator and take it to a shop that repairs them, as mentioned there tough units and do generate a lot of heat.
classicmuscle.442 is offline  
Old June 10th, 2019, 04:06 PM
  #17  
Running On Empty
 
Vintage Chief's Avatar
 
Join Date: Jul 2018
Location: Crystal Coast, NC
Posts: 1,424
^^x2^^ on what Chris said if you don't want to bother noodling about w/ it yourself. With regards to a generator or a newer style alternator. IMO, your old-style generator will be a far better generator than any modern alternator if you have your generator rebuilt - just my opinion, but they don't build them like that any more. A rebuild shop will check everything for you and do it right - bushings, brushes, bearings, commutator, armature and probably new windings - windings which most often are even far better than the original windings.
Vintage Chief is online now  
Old June 10th, 2019, 04:53 PM
  #18  
Registered User
 
Tedd Thompson's Avatar
 
Join Date: Oct 2004
Location: Forest Ranch Ca.
Posts: 5,180
Just my 2 cents . I would be worried about the tar drippings you mentioned on your first post. They maybe hot shellac which is used as a insulator for the windings. If the armature has grounded itself to the case or anything else you will get sparks when the ground is reattached. My advice is take it to a real generator/ starter shop and have someone else have a look at it, might save lots of time and grief..... Tedd
Tedd Thompson is offline  
Old June 10th, 2019, 07:09 PM
  #19  
Registered User
 
Join Date: Feb 2009
Location: Pittsburgh Pa.
Posts: 979
Originally Posted by Tedd Thompson View Post
Just my 2 cents . I would be worried about the tar drippings you mentioned on your first post. They maybe hot shellac which is used as a insulator for the windings. If the armature has grounded itself to the case or anything else you will get sparks when the ground is reattached. My advice is take it to a real generator/ starter shop and have someone else have a look at it, might save lots of time and grief..... Tedd
X2 on this. Black from the genny is not a good sign. If the regulator points stuck then the fields are probably smoked as well. Buy the regulator after you get a number off of the generator. If you get the gen number then you will be able to determine what amp it is.
stellar is offline  
Old June 11th, 2019, 07:28 AM
  #20  
Registered User
 
Tedd Thompson's Avatar
 
Join Date: Oct 2004
Location: Forest Ranch Ca.
Posts: 5,180
If you do this your self don't forget to polarize the regulator and my advise is deferentially get a new regulator, if it has smoked it's done. What ever Steller advises is Gospel..... Tedd
Tedd Thompson is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
cfair
Electrical
0
November 23rd, 2016 10:40 AM
rhett838
Electrical
8
August 23rd, 2016 11:34 AM
btolton
General Discussion
9
June 24th, 2014 06:06 AM
w-31cutlass
Electrical
10
February 18th, 2014 01:11 PM
sykosoft
Electrical
3
February 1st, 2012 07:22 PM


Thread Tools
Search this Thread
Quick Reply: Gen Light | Alternator Smoke | Black Residue on Alt Bracket?


Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.