88 5.7l alternator shot?

[POINTER94]

I think the alternator shot craps on me this weekend. It was covered in a black carbon and battery 1 went dead. Switched to battery 2 and shut down all electronics and hightailed it back so as to have enough batter to lift the stern drive to trailer home.<br /><br />In a sealed alternator what is this black carbon stuff? Is this consistant with the death of an alternator?

 

[Don S]

Re: 88 5.7l alternator shot?

That CARBON is probably belt dust caused by rusty pulleys grinding away the belts. <br />Is your alternator belt real loose? If so, that's why it doesn't charge.

 

[POINTER94]

Re: 88 5.7l alternator shot?

Hey Don, <br /><br />No the belt is very tight. I actually thought it might be the belt creating this but the consistancy of the "carbon" dust didn't seem consistant with the rubber of the belt. But at that point I didn't have any of the tools necessary to perform any tests, and work had me on the road the next day.<br /><br />There is no doubt that the belt is tight enough. I popped the cover while the engine was running and the alternator was spinnin along just fine, but the battery was slowly going down. I shut her down, switched over the battery (2) and you know the rest.<br /><br /><br />Thanks in advance.

 

[searay3]

Re: 88 5.7l alternator shot?

Pull the alt and take it to Auto Zone and have it checked if in doubt. Bad bearing would make noise. The belt is grinding away. That's about all that can cause the black stuff. What did the guages show?

 

[POINTER94]

Re: 88 5.7l alternator shot?

I didn't have the opportunity to put an amp/voltmeter to it but the dashboard guage read less than 10volts when I noticed it and made my way back. I didn't think a sealed alternator could create that mess but it just didn't feel like it was coming from the belt. I should probably replace that as well.

 

[paulie0735]

Re: 88 5.7l alternator shot?

Not sure exactly what type of alternator you have but if it’s the type with a built in voltage regulator than the black carbon dust is from the rubbing blocks which are part of the regulator. Its easy to tell, on the back will be a plastic box type of fitting with a wire or 2 connected and a couple of screws holding it in place. Disconnect the wires and undo the screws and it should just come off, inside you will likely find the carbon rubbing blocks have disintegrated. (Some are repairable but most are not)Head down to the dealer and buy a new regulator and screw it back in, should than be fine. Good luck.

 

[POINTER94]

Re: 88 5.7l alternator shot?

Don, Paulie, searay3, thanks for the responces. I will be on this mess this weekend and I will post back the results. <br /><br />I spend alot of time in hotels during the week.

 

[bruceb58]

Re: 88 5.7l alternator shot?

If this is your original alternator, I would suggest getting a whole new alternator. <br /><br />The difference in price between new and the regulator alone is not worth the hassle, especially when you consider it will fail when/where it will be least desirable.<br /><br />Just my $0.02!

 

[Bondo]

Re: 88 5.7l alternator shot?

If this is your original alternator, I would suggest getting a whole new alternator.

Ayuh,..... I Agree.......<br /><br />I also Agree,.....<br /><br />The Black is the Belt,.......

 

[imported_Dave_C]

Re: 88 5.7l alternator shot?

Check and see if the belt is riding on the bottom of the pulley. It is probably worn out (the black dust) and riding on the bottom of the pulley and no amount of tension will deliver enough torque to the alternator to charge the batteries.