Wire question

[hatzie]

A meter should sit at 14.5V with the engine running. 15+ is too high and 13.x is too low.
Amperage output is by demand up to the capacity of your unit... 10SI=63A, 12SI=78A-94A, CS130=105A. If the battery is low or has a dead or partially shorted cell it'll cause the alternator to push more current and heat stuff up. If you have poor connections to the battery from the alternator you'll get the same results.

[ShinyC10]

Originally Posted by hatzie

A meter should sit at 14.5V with the engine running. 15+ is too high and 13.x is too low.
Amperage output is by demand up to the capacity of your unit... 10SI=63A, 12SI=78A-94A, CS130=105A. If the battery is low or has a dead or partially shorted cell it'll cause the alternator to push more current and heat stuff up. If you have poor connections to the battery from the alternator you'll get the same results.

Tested the alternator and is was fine, replaced the connectors to it and the fusible link. Chased down all the wires and still the fusible link gets hot when the truck is running. I'm at a loss. The red wire that comes off the fusible link and plugs into the alternator gets hot but the other red wire in the fusible does not. Also, turned the truck on for maybe 20 seconds and the alternator is burnin up.

[hatzie]

Be sure the ground cable to the alternator bracket is making good contact and the bracket is making good contact with the alternator itself as well.

Star washers are your friend.
The easy way to test this is reading volts from the BAT terminal to the alternator case and comparing to the volts across the battery terminals. They should be the same. If they aren't you have a bad contact at the J-Block or the starter or the ground ^^^ is not making good contact. You can do a voltage drop test across all of these connections.

Easy Voltage drop tests to check your cables...http://aimpartsonline.com/reduce%20warranties

Is the 14ga red sense wire on the plug intact from the alternator through its' fusible link to the starter? Can you read more than @.1 DC volts from the BAT terminal to the sense wire? This means there's a voltage drop across these wires. There shouldn't be. The J block is fed from the starter through a fusible link. The sense wire is attached at the same place on the starter through a different fusible link.

Internal failure. Bad regulator, bad diode, improper alt fan, bad bearing, defective heat sink??

[ShinyC10]

Originally Posted by hatzie

Be sure the ground cable to the alternator bracket is making good contact and the bracket is making good contact with the alternator itself is as well.

Star washers are your friend.

Also, we noticed that the dome light won't go out when the truck is off and doors are shut. It just dims down when I shut the door

[ShinyC10]

Originally Posted by hatzie

Be sure the ground cable to the alternator bracket is making good contact and the bracket is making good contact with the alternator itself is as well.

Star washers are your friend.

ill check that

[hatzie]

The jamb switch has failed or the switched wire has rubbed through and is grounding out. The dome/courtesy lamps use a switched ground on the doorjamb and the headlamp switch.

The voltage drop tests across the cables are bloody easy and quick to do. They don't require $1000 in tools to execute either.

[ShinyC10]

Originally Posted by hatzie

Be sure the ground cable to the alternator bracket is making good contact and the bracket is making good contact with the alternator itself as well.

Star washers are your friend.
The easy way to test this is reading volts from the BAT terminal to the alternator case and comparing to the volts across the battery terminals. They should be the same. If they aren't you have a bad contact at the J-Block or the starter or the ground ^^^ is not making good contact. You can do a voltage drop test across all of these connections.

Easy Voltage drop tests to check your cables...http://aimpartsonline.com/reduce%20warranties

Is the 14ga red sense wire on the plug intact from the alternator through its' fusible link to the starter? Can you read more than @.1 DC volts from the BAT terminal to the sense wire? This means there's a voltage drop across these wires. There shouldn't be. The J block is fed from the starter through a fusible link. The sense wire is attached at the same place on the starter through a different fusible link.

Internal failure. Bad regulator, bad diode, improper alt fan, bad bearing, defective heat sink??

So I got the grounds improved and the alternator still seems to be heating up. It is putting out 14.4/14.5v but continues to heat up in the matter of a couple minutes. The wire off the alternator that runs to the fusible link is getting hot as well but the second wire within the fusible link doesn't.

[hatzie]

What's the voltage drop across the charge wire?

[ShinyC10]

Originally Posted by hatzie

What's the voltage drop across the charge wire?

Could you explain to me how to do a "voltage drop" sorry, watched a couple videos but they don't really explain well


Edit: just noticed your link lol

[hatzie]

It's measuring the difference from one end of the wire to the other. It's measuring the effect of resistance in the circuit.
Set the meter on DC volts and a range above 15v.
Touch a digital meter probe to each end of a wire. If there's a voltage drop from one end to the other you'll see a low voltage reading on the meter. 0.1VDC is acceptable the more volts you get the less acceptable it is.

Corroded terminals, poorly crimped terminals, loose terminals from age, corrosion inside the wire jacket, paint insulating grounds, ... will cause a voltage drop.

It's really simple. Here are some hookups from the linked article on how to perform this diagnostic procedure.
Testing the charge wire... Note you can test from the alternator BAT stud to the battery a shown then move the battery probe to the J-Block.


This is testing the voltage drop between the battery and the alternator case. Your ground wire connection to the ALT


This is the voltage drop across the sense wire.


Test every cable run in the charge circuit.
There are only 5

1. Bat to Starter Big fat 2ga wire
2. Starter to J-Block
3. J-Block to Alternator BAT stud (Charge wire that's getting hot)
4. Starter to Alternator plug. (Sense wire)
5. Alternator case to Battery Ground post.

It may turn out that all your cables are pristine... If that's the case then you may have a failing alternator.

[ShinyC10]

Originally Posted by hatzie

It's measuring the difference from one end of the wire to the other. It's measuring the effect of resistance in the circuit.
Set the meter on DC volts and a range above 15v.
Touch a digital meter probe to each end of a wire. If there's a voltage drop from one end to the other you'll see a low voltage reading on the meter. 0.1VDC is acceptable the more volts you get the less acceptable it is.

Corroded terminals, poorly crimped terminals, loose terminals from age, corrosion inside the wire jacket, paint insulating grounds, ... will cause a voltage drop.

It's really simple. Here are some hookups from the linked article on how to perform this diagnostic procedure.
Testing the charge wire... Note you can test from the alternator BAT stud to the battery a shown then move the battery probe to the J-Block.


This is testing the voltage drop between the battery and the alternator case. Your ground wire connection to the ALT


This is the voltage drop across the sense wire.


Test every cable run in the charge circuit.
There are only 5

1. Bat to Starter Big fat 2ga wire
2. Starter to J-Block
3. J-Block to Alternator BAT stud (Charge wire that's getting hot)
4. Starter to Alternator plug. (Sense wire)
5. Alternator case to Battery Ground post.

It may turn out that all your cables are pristine... If that's the case then you may have a failing alternator.

Tried that top picture and if we did it correctly (kinda hard to mess it up) it's reading at .8v. When we run the truck, the alternator seems to be losing .5v by the time it gets from the alternator to the fusible link

[hatzie]

That's way too high. You have dirty connections or corroded wires or a damaged wire. No section of the wire should show a drop of more than .1V to .2v

You measured the voltage drop across #s 1, 2 &, 3 on my list. Test each section to see where the drop actually is. It's not likely all three.

What do you get from the red wire on the Packard 56 two wire alternator plug to the Battery positive post? This is #s 1 & 4 on the list.

What does the alternator case to battery negative post give you? This is #5 on the list.

Deoxit is still stocked by Radio Shack. You can hit the ring terminals with it after scrubbing with some emery cloth.
When you get the connections cleaned up and passing current the way they are supposed to...
I usually spray all the battery cable connections in the engine bay of my cars with Wurth HHS-2000. You can use Fluid Film or CRC Battery Terminal Protectant. You just need to keep the weather out.

[ShinyC10]

Originally Posted by hatzie

That's way too high. You have dirty connections or corroded wires or a damaged wire. No section of the wire should show a drop of more than .1V to .2v

You measured the voltage drop across #s 1, 2 &, 3 on my list. Test each section to see where the drop actually is. It's not likely all three.

What do you get from the red wire on the Packard 56 two wire alternator plug to the Battery positive post? This is #s 1 & 4 on the list.

What does the alternator case to battery negative post give you? This is #5 on the list.

Deoxit is still stocked by Radio Shack. You can hit the ring terminals with it after scrubbing with some emery cloth.
When you get the connections cleaned up and passing current the way they are supposed to...
I usually spray all the battery cable connections in the engine bay of my cars with Wurth HHS-2000. You can use Fluid Film or CRC Battery Terminal Protectant. You just need to keep the weather out.

Alt. Red wire to the BAttery posi=.03 and so does the alt. Case to battery negi. #3 on the list=.25 and #5=.02. Have to rig something to get to starter, headers are in the way

[hatzie]

That narrows it down a lot.
The alt plug sense wire better than excellent to the battery positive so the big wire to the starter is just fine.
The ground is better than excellent.

#3 is high but it shouldn't make the alt get screaming hot. Check the crimp on the new ring terminal to the J-block. Solder it if necessary.

This leaves the J-Block to Starter wire in the charge circuit and the alternator itself. It could be both.

[ShinyC10]

Originally Posted by hatzie

That narrows it down a lot.
The alt plug sense tests excellent to the battery positive so the big wire to the starter is just fine.

#3 is high but it shouldn't make the alt get screaming hot. If this was the only problem I might leave it alone.
This leaves the J-Block to Starter wire in the charge circuit.

I'll check those out tomorrow. Really appreciate all the help!

[ShinyC10]

Originally Posted by hatzie

That narrows it down a lot.
The alt plug sense wire better than excellent to the battery positive so the big wire to the starter is just fine.
The ground is better than excellent.

#3 is high but it shouldn't make the alt get screaming hot. Check the crimp on the new ring terminal to the J-block. Solder it if necessary.

This leaves the J-Block to Starter wire in the charge circuit and the alternator itself. It could be both.

Long time no reply on my part!!!
Dad and I replaced the battery, alt, and starter wires and saudered the connections and the alt still was heating up the fusible link. So my dad took it to an electric shop for them to really test it out and turns out the alt is bad. So got another one on the way.