My 1971 521

[mainer311]

I don’t think that matters. Everything is just connected on the starter post. When the engine is running, the post is only used to connect the alt to the battery. Otherwise it just sits there and does nothing. When you turn the key to “start” the little black wire grounds the solenoid which acts as a relay for the starter motor. It grounds out the negative side of the motor and allows it to crank. When the circuit is normally open, power is always on the post, but since there is no ground, the motor circuit isn’t completed.

[Charlie69]

15 hours ago, d.p said:

Fuck this stupid alternator, took the truck out today and low behold alternator not charging again.  The highest the voltmeter got to was 12.9 but hovered around 12.4 the entire time.  Only drove it roughly 22 miles but that same story the entire time.  Charge light off but simply not doing its thing.  It must be a loose belt or wire, otherwise not sure what else it could be.  This started the other night when I drove it around and turned the headlights on.  

If your battery is charged up then your alternator does not need to charge.  Does the idiot light come on when you turn on the ignition?  Does the light go out after you start the engine?

[d.p]

5 hours ago, Charlie69 said:

If your battery is charged up then your alternator does not need to charge.  Does the idiot light come on when you turn on the ignition?  Does the light go out after you start the engine?

wait so my battery isn’t always charging?  Meaning my voltmeter isn’t supposed to show 14.x while driving all the time??

[d.p]

Oh and yes the light goes out but the that light is out all the time when the truck is running and the battery is still charging. Meaning the volt enter is showing 14.x. 

Edited April 30, 2021 by d.p

[mainer311]

39 minutes ago, d.p said:

wait so my battery isn’t always charging?  Meaning my voltmeter isn’t supposed to show 14.x while driving all the time??

 

No, you should always see high 13's/low14's. The alternator still needs to put out a voltage high enough to run all of the electronics in the car. Think of the battery as a large capacitor that just sits there and waits to be needed. It starts the car because you can pull 100's of amps from it. Once the alternator spools up, the battery gets refreshed, and then goes back into waiting. In most cases, it'll also get you home if the alternator shits the bed.

 

Car batteries are only used for starting, and for when the car demands more current than the alternator can handle.

Edited April 30, 2021 by mainer311

[datzenmike]

There's battery on one side of the red charge light. The other side goes to ground through the diodes in the alternator when not charging. When charging there is 14.5 now on the diode and as it also connected to the battery 14.5 or so on both sides of the red light. With equal potential on both sides there is almost now current flow and the bulb stays dark. Even a couple of volts difference won't light it enough to see. If the light is out it means there is equal voltage on both sides, could be any amount.

[d.p]

I guess it doesn't matter cause the alternator is toast according to the alternator shop.  Figures my luck with those AC DELCO remans.  Now I just wait for the REMY one @mainer311 recommended.  

[thisismatt]

This is why I would just stick with a used or new oem, or a rewound high output.

[Charlie69]

The number that mainer posted is for a non internal regulated alternator.  This means you use an external regulator.  I would investigate your wiring as you are having a lot of problems with charing/alternators.

 

My point was has your battery died and left you stranded.

[Charlie69]

I have my factory alternators and starters rebuilt and bumped up in amperage by my local rebuilder.  Same company since the 70s.  I am fortunate to have Genstar still in business after all these years.

 

Is remy actually AC Delco?

[mainer311]

3 minutes ago, Charlie69 said:

The number that mainer posted is for a non internal regulated alternator.

 

He knows. I mentioned going back to external VR with a 60A alt from a 510.

[mainer311]

Just now, Charlie69 said:

I have my factory alternators and starters rebuilt and bumped up in amperage by my local rebuilder.  Same company since the 70s.  I am fortunate to have Genstar still in business after all these years.

 

Is remy actually AC Delco?

 

The Remy alts are remanufactured Hitachis.

[d.p]

5 minutes ago, thisismatt said:

This is why I would just stick with a used or new oem, or a rewound high output.

 

My man, I bought 2 NEW 200SX alternators and they are both bigger than the reman'd ones which simply don't in between the block and the idler arm on our trucks.  So I can't get a new one from a 200SX.  

1 minute ago, mainer311 said:

 

He knows. I mentioned going back to external VR with a 60A alt from a 510.

 

Yeah I am aware and have the a working external VR to use.  

[Charlie69]

I know they are that, but is Remy actually AC Delco

[d.p]

6 minutes ago, Charlie69 said:

The number that mainer posted is for a non internal regulated alternator.  This means you use an external regulator.  I would investigate your wiring as you are having a lot of problems with charing/alternators.

 

My point was has your battery died and left you stranded.

 

No it hasn't but I don't drive that far at all so hasn't had a chance to I guess.  I just know this truck like the back of my hand and when something is amiss I know it, why its amiss is anyone's guess lol.   And my wiring did not change at all, the only thing that did was going from a 30AMP ER to a 60AMP IR with the jumper.  

Edited April 30, 2021 by d.p

[Charlie69]

Yes I am impressed that you have done as much work on your 521 as you have.  Some people get these little trucks and when there is problems with them they sell them.  Any thing old takes more maintenance than say a new car.

 

Once you get you 521 dialed in you will have many trouble free miles with just regular maintenace.

[d.p]

22 minutes ago, Charlie69 said:

Yes I am impressed that you have done as much work on your 521 as you have.  Some people get these little trucks and when there is problems with them they sell them.  Any thing old takes more maintenance than say a new car.

 

Once you get you 521 dialed in you will have many trouble free miles with just regular maintenace.

 

Gee thanks dad!  

[mainer311]

25 minutes ago, Charlie69 said:

I know they are that, but is Remy actually AC Delco

That’s my assumption. In the end, most of this stuff all comes from the same factory in China. You can’t get a legit alternator anymore unless you spend 100’s.

[Charlie69]

1 minute ago, d.p said:

 

Gee thanks dad!  

I have no children.  LOl

[d.p]

@mainer311 Do you know which model years that REMY came out of?  Just want to see if there is something locally I can get while I wait for that one to arrive.  

[mainer311]

7 minutes ago, d.p said:

@mainer311 Do you know which model years that REMY came out of?  Just want to see if there is something locally I can get while I wait for that one to arrive.  

It’s listed as 70-73 510. I believe the 60A version was in cars that had A/C.

Edited April 30, 2021 by mainer311

[d.p]

2 minutes ago, mainer311 said:

Early 70’s 510. I believe the 60A version was in cars that had A/C.

 

Thanks, looks like 71 w/AC used that 60A externally regulated.  

[datzenmike]

I think you'll find any 510 50/60 amp alternator is also larger case than the 521. This is because there is no frame or idler arm under it, they can be as big as they like. If they were a good fit everyone would be switching to them for their 521 and 620s, and they don't.

 

Early 510s were ...

30 and 33 amp through '69

35 amp through '71

There was an optional US and Canadian 50 amp '72 on

[mainer311]

4 minutes ago, datzenmike said:

I think you'll find any 510 50/60 amp alternator is also larger case than the 521. This is because there is no frame or idler arm under it, they can be as big as they like. If they were a good fit everyone would be switching to them for their 521 and 620s, and they don't.

I did just fine. I don’t know how many times I have to tell you.

Edited April 30, 2021 by mainer311

[datzenmike]

Didn't say impossible just not a good fit.