Alternator issues....

[Catbox]

This is from the "What have you done to your Squarebody" post.
It will keep the information in one spot and easy to keep track of for all of us.

Our truck has had a random charging issue since the alternator that came on it died a year or so ago.
@Maxwellvis has been daily driving it and the gauge has never really seemed to read much above 12v. Some times it would just barely start the engine other times he would have to charge the battery.

Not long ago it crapped out totally on him.
Dead battery at his buddies house.
Max let his dink bag friend do the electrical testing and figured that the alternator had died again.
They ran to the parts store they both work at and got a fresh rebuilt one and stuck it in there.
Meanwhile the battery was charging while they ran around.

They get back and slap the new thing in there and boom!
**** starts up and Max has to leave shortly after they buttoned it up.
He gets home and the battery is dead again.

Junior yards the new alternator out and takes the other one with him to have them tested.
Brand new one is DOA. Junk was returned to the store.
Old one that is supposed to have been the original issue turns out is good.

So he put that one back in and did some looking around.
Turns out the charge wire from the BATT terminal on the alternator had come out of the crimp connector that is up on the firewall.

There is the actual reason the thing will not charge.

FAST FORWARD A COUPLE DAYS.

Same issue.
Hard starts and not much power coming from the alternator.
It runs iffy and puts out some juice sometimes and none other times.
Never puts out 14.7.
Not once.

The other night he was furious and headed out to work on it, I joined him.
So we did some online sluethery and learned how the GM charging system works.
We have a 12SI 94 amp alternator from a mid 80's Camaro on it.

On the BATT terminal it had battery voltage, 12.something.
It had the constant 12 volts and the switched 12 volts.

**** this alternator.

He was all irritated as he would have to wait to go and get a new alternator in the morning.
I asked about any spares I had in the parts hoard and all have been pillaged and plundered that would have any sort of chance at working in the truck.

I brought up swiping the one from my 1954 Chevy Bel Air.
YOU HAVE TO LOVE THAT PARTS FROM VASTLY DIFFERENT CARS FIT EACH OTHER.

Well for the most part.
The housing was clocked 180 degrees out, but with enough washers and spacers, we got it made.

Start the truck up and boom!
The alternator made the voltage jump to 14.2 and it amazed the boy!

While we were in there we also changed out the charge wire that was probably original and 12 gauge with a fresh 6 gauge welding cable.
That should help keep things happy as well.

Soon we are going to build a complete set of 0 gauge welding wire battery cables for it as well.

 

[Catbox]

So it has killed yet another alternator.
The one from the Bel Air lasted a few days and is now verified dead by the Autozone guy.

So we are here to discuss trouble shooting the charging system and the woes it brings to us all...

1.) We have replaced the charge wire from the BATT terminal to the junction block on the firewall.
- Still kills them.

2.) We have clipped off the alternator plug to ensure a good connection. Installed simple crimp connectors to facilitate the connection to the alternator.
- Still kills them.

3.) We installed a ground strap on the frame where the battery ground cable connects and goes directly to the alternator mounting hardware.
- Still kills them.


Now we are all caught up.

Tomorrow while @Maxwellvis is at work, I am going to head to the junkyard to find us a fresh alternator victim and will buy the warranty to go with it. That way we can keep killing them until we have a solution. After that we plan to upgrade to a fancy newer version.

 

[Catbox]

Some photos for your eyes to peruse...

This is the turd we are working with.
A 1979 Chevrolet Camper Special with the 454 in it.

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Here is the initial fresh alternator we had installed just over a year ago.

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You can also see the ground strap we installed from where the battery cable connects to the frame. That strap came off a donor at the junkyard and connects to the lower mounting bolt.

The meter says there are 0.00 ohms resistance from the alternator case to the battery terminal.

 

[Catbox]

Now where do we go from here?

I am fresh out of current ideas.
I need some fresh direction from you fellers.

 

[Vbb199]

Is there something causing a heavy drain on the battery thus laboring the alt excessively?

As in, check batt voltage prior to cranking, check it while running. If theres no increase, that would seem suspect.

Just another thought that may or may not carry weight, is the distributor all set in terms of feed and ground? Asking if its somehow backfeeding to the alt? Just a thought too....

 

[Vbb199]

Suppose you could verify no plug wires are nicked and arcing over to the block/power/ground or anything as well, sir.

 

[AuroraGirl]

Just because of the 1954 bel air alternator being in unknown shape, it may have lost its residual magnetism
https://www.delcoremy.com/the-latest/2013/march/tech-tip-flash-the-field

Before you remove the alternator, first try to determine if a loss of residual magnetism is causing the loss of voltage. You can do this by flashing the field:

1. With the vehicle ignition in the “off ” position, remove the rubber boot from the alternator battery terminal and the rubber grommet from the small “R” terminal.
2. Take a small piece of wire and touch one end of it to the battery alternator terminal. Then touch the other end to the small "R" terminal. (Note: This may create a small spark, which is normal.)
3. Remove the wire and start the vehicle. The voltmeter should now increase its voltage reading to around 14 volts.
4. If the alternator isn’t charging, then re-check all connections and belt tension before removing the alternator.
5. Put the rubber boot and the rubber grommet back on.

 

[Ricko1966]

Okay alternator,starters and I buy new, good used or repair myself.Rebuilders and big box stores are in bidding wars cheapest wins not best wins.Sounds like you needed brushes in your bad one and It say just bad luck on the last one. I'd buy brushes and a
Diode trio and put it in the first one and motor on.

 

[Powerhouse Ranch]

461, very admirable. and it is not a turd! tis a very sexy truck my friend

 

[Powerhouse Ranch]

Put this in the other thread, not sure if you read it:

My brother's starting system went out last spring in his '77 Cheyenne. Ended up being a whole combination of things:

-Alternator.........got a nice reman one at Autozone, old one was drawing from the battery, was original to truck
-Battery.............got a new red top optima battery from Summit, old one was old/junk
-Ground cable......got new ground (alternator to ground post) from LMC, was corroding out
-Starter.............got a starter from Autozone, may have had to do with starter solenoid but decided just to do the whole unit
-Installed a negative terminal battery master switch for the winters (i personally disconnect the cables entirely but either or)

Ever since then she starts all the time, every time

 

[Rusty Nail]

Hay that's a good lookin truk!

Did somebody say starter yet?
Why not? Wants a picture of the connections on the solenoid..they got a frayed wire down there on the starter -right?
Do the turn signals function as intended?

Have you even seen one of the wires in a dual filament bulb - fall down and short-circuit to the other filament?


https://www.dictionary.com/browse/filament?s=t

he said current ideas

 

[Ricko1966]

Does your truck have an alternator light? Did it have an alternator light. Without cracking a book I'm not certain how the field windings are supposed to be excited on your truck most of the time it is 12v ignition to light bulb to alternator windings.Grab a 12v test light clip the test lead to battery + back probe the field connection with the probe end see if the light comes on, start the truck it should go off and the voltage comes up.

 

[Ricko1966]

Well just by dumb luck I was looking at a pic of your truck in another thread. Does this truck have electric fans? What are they off of. The reason I ask is other people on other forumns have had trouble killing alternators by not using the correct fan relays. If you got something you bought as a kit nbd you're probably fine, but some of the junkyard fan motors required a relay with a diode to prevent voltage spikes which were killing alternators. Something to think about. Or do some research.

 

[Scribbles]

Have you checked for a draw on the battery?
I've had multiple customers over the years that had phone chargers that they left plugged into the cigarette lighter that had draws of up to 3 amps. The really bad culprits are the generic ones from the dollar store.

 

[Catbox]

Work has been making things difficult to do this last week.
I will read through all of these thoughts and suggestions later this week when my project is done and out the door.

I did make it to the junkyard yesterday to find only 3 10/12SI alternators in all of the GM vehicles present. THREE! Crazy talk.

The first one was in a '86 El Camino and I pulled it out and threw it in the cart.
Second was in a 1980 Van and had the wrong mounting orientation.
The last was so very corroded that it did not want to turn.

So I purchased the El Camino one and the extra warranty.
Now I can swap out alternators as much as I want for the next 13 months.

We stopped and had it tested at Autozone.
That guy was a turd and it took him 15 minutes to figure out how to hook it up.
He said it was dead and handed it back.
I do not have much faith in his prognosis.

Tomorrow Max will be putting the alternator in the truck to spin it up and confirm the AZ turds findings.