Up in Smoke - Not the movie, my alternator

[OldSchoolAmerica]

Returning from successful NYS inspection on a beautiful sunny Rochester day (humor me, we don't get many up here) I started smelling some electrical smoke. I look down at the gauges and the voltmeter is pegged past the red overcharge. I start slowing down to pull over, the truck dies and all the needles fall to zero... this was probably a good thing as the main fuse blew and likely saved me from serious wiring/component damage. After examining the alternator it appears the voltage regulator, rectifier end assembly and windings leads are toast, see pictures below. So, before I install a new one, I would like to mitigate any possible causes of this (in my control) and therefore looking for your help to identify possibilities.

To start the list I reached out to a very helpful vendor and he said the causes could have been the following:

• loose battery connections
• damaged batteries (a weak or dead cell)
• short in the alternators stator/field windings/diodes
• water/moisture in the regulator housing
• overloaded electric beyond the 60 amp rating

​
Well, I examined items 1, 2 and 5 which all checked out fine. In fact, I have new batteries and cables and very little load. Items 3 and 4 are totally out of my control. So, with that, any more possibilities....

 

[doghead]

Inspect your positive battery cables for a short to ground(especially where it goes through the hole in the frame, and under the edge of the firewall), as these are common areas the cable insulation gets worn through.

A dead short could cause the failure you experienced, as well as the other possibilities you posted.

Have your batteries tested, before you rule them out.

I've seen the loose connection cause this more than once. If the alternator does not sense battery voltage, it goes to maximum output, until the regulator fails(like yours did).

Also be sure you have a good engine to frame ground.

 

[NDT]

Ouch! A3's have a main fuse? Looks like the internal voltage regulator failed and sent the alternator into max charge, which it tried it's hardest to do.

 

[glcaines]

Sorry to hear about your alternator. Now would be a good time to check the alternator bracket for cracks since your alternator is dismounted. A3 alternator brackets tend to crack and fail.

 

[OldSchoolAmerica]

Thanks Doghead - I will be sure to double check everything before the new alternator goes in. Let me know if you're ever out this way. I owe you lunch for all the help you provided me.

NDT - Yes, it definitely appears the alternator gave its all.

glcaines - Appreciate the recommendation... you were right on. I actually found that last year when going over the engine and had it reinforced, see image below. Definitely not the best design.

 

[Diecorpse]

That sucks, I hope you figure out why it happened. My alternator failed because I had a bad cell in one of my batteries, which were less than two years old. The battery grounded itself so to speak, and less than five min when something didn't seem right, the alt burned up. The regulator was completely toast and it melted my ground wire from the alt to the frame. I found it cheaper to buy a newer alt and it is stronger with a warranty. I got an Ac Delco that is 24v and 120 amps for $350. At least if you fry that one, your covered under warranty, if not you can turn in your core for $150 and get another from most local auto shops. Do you plan on repairing your alternator or are you looking for a new one?

 

[swbradley1]

At least I know exactly what caused mine, I tried to slave my dead 818 and released the magic smoke.

DH has pointed you in the correct direction.

 

[OldSchoolAmerica]

That sucks, I hope you figure out why it happened. My alternator failed because I had a bad cell in one of my batteries, which were less than two years old. The battery grounded itself so to speak, and less than five min when something didn't seem right, the alt burned up. The regulator was completely toast and it melted my ground wire from the alt to the frame. I found it cheaper to buy a newer alt and it is stronger with a warranty. I got an Ac Delco that is 24v and 120 amps for $350. At least if you fry that one, your covered under warranty, if not you can turn in your core for $150 and get another from most local auto shops. Do you plan on repairing your alternator or are you looking for a new one?

Looking for a new one... that is, after I go through the charging system. The fourth of July is over and I don't want to see any more fireworks.

Was that Delco a drop in, or required modifications?

 

[tm america]

If you send me the old bracket and pulley i will make you a kit to install a 27si delco alt .. i will make your bracket for free all you have to do is buy the alt which goes for around 115 brand new with a lifetime warranty.. pm me if interested.. the 27si is a 65 amp alt and has proven very reliable.i could probably do it with just the main bracket and adjusting ..i will even pay for the shipping..i have been wanting to make this kit for a while now..let me know

 

[OldSchoolAmerica]

If you send me the old bracket and pulley i will make you a kit to install a 27si delco alt .. i will make your bracket for free all you have to do is buy the alt which goes for around 115 brand new with a lifetime warranty.. pm me if interested.. the 27si is a 65 amp alt and has proven very reliable.i could probably do it with just the main bracket and adjusting ..i will even pay for the shipping..i have been wanting to make this kit for a while now..let me know

TM - Definitely have my interest. However, I can't let you pay for shipping. Will PM shortly.

 

[tm america]

I will pay shipping both ways..and i will get the brackets made up within a few days ..you are helping me as much as i would be helping you..i have been wanting to make these brackets for a long time now .i have the 800 and 900 series kits ready to release to so i really just need to have the a3 kit and i will have most of them covered.Once i have the 24 volt side covered i am gonna work on getting the 12 volt kits for them to..

 

[swbradley1]

George is the man when it comes to making the brackets to put the Delco Alternators on the trucks. I have one on one of my Deuces and even used the extra bracket to put a different alternator on my New Holland backhoe.

Just don't him talking about fab work...........

 

[tm america]

Ya Steve i might talk a little bit much about things i like to do..But that's just a maybeMaking military trucks better is just one of my little gifts i also act as training wheels for 4x4 quads when offroad

 

[OldSchoolAmerica]

I'm heading to the garage now to pull the pulley from the alternator. Will have them in the mail tomorrow. Will also send plenty of pictures to help the creativity process...

 

[swbradley1]

Ya Steve i might talk a little bit much about things i like to do..But that's just a maybeMaking military trucks better is just one of my little gifts i also act as training wheels for 4x4 quads when offroad

Touche' buddy, touche'


Say hi to M for me.

 

[tm america]

Awsome..There are two things that would help .If you could scribe where the alt normally sits on the main bracket and take a pic of where the main bracket would mount on the engine..i was looking at an a3 at haspin and have a pretty good idea of how i will build it..Since it doesnt have to pivot i am gonna make it similar to the stock one but with a piece of metal goin along the bottom to add a angle and more than double the rigidness of the bracket.i am also gonna do a different adjusting arm that is reinforced to keep the harmonics down as well

 

[tm america]

Touche' buddy, touche'


Say hi to M for me.

Sure will buddy .. Did you get that crappy situation taken care of when you got home?

 

[Diecorpse]

The Ac Delco did require a custom made bracket and had to get smaller belts too. This was done on my A2 so I know it will be a little different. The guy that did gave me a good deal on it. Hundred bucks for the bracket with labor. The thing I like most about this set up, is the fact there is only one bolt that holds the alternator to the bracket, so if I needed to remove it, it would be very simple compared to the stock version. Its a large, long grade eight bolt in case anyone was wondering. I also got rid of the military batteries I had and went with Napa batteries that were for heavy industrial equipment that were at 985 cca each. Ever since, all was well. I'm gonna go mess around with my truck tomorrow so if anybody wants to see how mine is set up, I can take some pics and post them. I did forget to mention that the same pulley was used, but it was drilled out slighty because the shaft on the Delco was bigger.

 

[tm america]

I sell my 24 volt 27si kit for the a2 for 61.00 with shipping ..My kit uses the stock belts and is a dirrect bolt on for it..I am gonna make the a3 kit the same way some it is a dirrect bolt on and it will use the stock belt

 

[M35A2-AZ]

I sell my 24 volt 27si kit for the a2 for 61.00 with shipping ..My kit uses the stock belts and is a dirrect bolt on for it..I am gonna make the a3 kit the same way some it is a dirrect bolt on and it will use the stock belt

$61 for the mount sounds like a good price.