[69velle]

Hello all
I rewired my car with the aaw classic update wire harness last year and my CS130 alternator started whining, sounded like a turbo or supercharger. I changed it out with a reman from autozone and when I tension the alternator pully to 1/2” of flex, the replacement alternator whines again and gets too hot to touch. If I loosen it, the whine decreases but the belt will slip upon startup. Any thoughts to the issue of why the alternator is whining?

 

[67-468]

Sounds like it has a bad diode in it. Very very common with those alternators. It will cause the case to get very very hot. And it sounds like it has a bad bearing in it.

 

[69velle]

Ordered a new build from powermaster, hopefully that fixes the troublesome rebuilds

 

[DUTCH MAX HEADWORK]

Check your pulley alignment and fully charge the battery before you install your new alt.

If you want to check for a bad diode, do an a/c ripple test.

Set the DMM to read AC volts and measure the battery while the engine is properly warmed up and idling at approximately 1,500 rpm, which will put some load on the electrical system with the headlights and blower turned on. If there is more than 0.1 volt (50-100mV, depending on the vehicle) of AC ripple, then the alternator is most likely bad.

 

[Malibu70]

Two different internally-regulated CS130 alternators show the same symptoms (noisy and hot) after a wiring harness replacement. I think two possible causes for this:
Alternator is not connected to its voltage sense wire, and does not see system voltage so it increases output voltage. Factory had a Gen light in the dash board that presented some voltage to the external regulator to allow voltage control.
A wiring problem such as a short to ground elsewhere on the car, and the alternator is increasing output to maintain voltage. If that is the case, a melted wire or fire might result.

 

[DUTCH MAX HEADWORK]

Make sure you are not showing 12 volts at the L terminal with the key on and the engine off. You should less than 9 volts. A full 12-volt signal will destroy the CS130 regulator.

Do you run a warning light in the dash? Does it come on with the key in the run position with the engine off then go out as you start and run the engine?

What's your voltage at the alt output after running ay above 1200 rpm and at 1200rpm?

The CS130 does not necessarily need to be connected to a sense wire as it has an internal sense connection. However, it is best to hook up the sense line to the horn relay or battery depending on your system layout. If running the stock wiring layout where most electrical devices pull power from the 4 way connector/horn relay, the sense wire should be attached there. If you are pulling power off the battery for fans or other high current devices, then you can hook to the battery or the 4 way splice/horn relay.

 

[DUTCH MAX HEADWORK]

Make sure you have a good ground to that alternator. I suggest using the lug at the back of the alternator case and install a 6 gauge wire and run it directly to a clean shiny metal ground on the engine. Check your negative battery cable attachment points and make sure they are clean shiny metal attachment points.

 

[69velle]

thank you for the detailed replies. I do have a generator light that works. Measuring the voltage at the brown wire with key on is 8v. Voltage across the terminals while running is 14.3 with the new alternator from powermaster. Pully alignment and tightness seems good. I do not have a dedicated ground from the alternator as I have a stainless spacer that runs between the alternator case and bare aluminum head. I can put one together though. All my other grounds (firewall, battery, etc)are brand new 0 gauge to bare head, and bare head to fresh metal on frame.

 

[DUTCH MAX HEADWORK]

It sounds like you got the ground covered. It wouldn't hurt to add a dedicated ground wire. Those alternators need a good ground otherwise the regulator doesn't work right or they fry. Sounds like you got it covered now charging good your voltages look good.

 

[69velle]

Can I still run a 50ohm resistor as backup to the idiot light?

 

[DUTCH MAX HEADWORK]

Can I still run a 50ohm resistor as backup to the idiot light?

Yes the first picturei n post six shows you how to set that up they run parallel.