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I drove my all original 82 today without issues when driving. When I got home I smelt electrical when I opened the door. Then seen smoke under the hood, so I quickly disconnected the battery (the negative was hot but not melted). Opened the hood and the smoke was coming from the alternator. The alternator is about 5 years old oem reman. Tore down the alternator and the bearings are fine, no rubbing on the stator. There was a piece of plastic that melted all over the rectifier (caused the smoke). The rectifier is burnt out. The car also smelled like the fiberglass got hot somewhere so I inspected the wires that connect to the alternator and they were not melted. I could only check them until they go into the frame and couldn't check them on the other end. (I plan to remove the battery and storage box to see if i can see the wires) My concern is how do I check to see if the alternator short made the wires hot or if the wires shorted and burnt the rectifier? I would hate to replace the alternator and burn up the new one or worse catch the car on fire... Any suggestions?
2020 Corvette of the Year Finalist (performance mods)
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Your thinking is accurate. Get a meter and disconnect the alternator and probe the postive wires to ground with both ends disconnected to see if they are shorted. If not the alternator was overcharging
I had bad luck with ac delco chinesium rebuilds, it stunk bad and dragged an additional 50 rpm compared to original rebuilt at home. Do you onow where how rebuilt?
i would try another option.
do you have original? Pics?
I had bad luck with ac delco chinesium rebuilds, it stunk bad and dragged an additional 50 rpm compared to original rebuilt at home. Do you onow where how rebuilt?
i would try another option.
do you have original? Pics?
Yes I am going to put the original back on it. The alternator was changed tring to fix another problem, by the previous owner, but ended up being something else. I will add some pictures tomorrow.
New reman alternator in my 69 smokes also,if i unplug the 2 wire side plug it stops....gotta figure it out, did your old alternator work? or do you still have the same issue?
you are both over charging. replace the regulator. and both of you. check numbers on alt cases to see if they are orig to the car or replacement. not that it adds any real value, but hanging on to the easy to hang onto stuff...
New reman alternator in my 69 smokes also,if i unplug the 2 wire side plug it stops....gotta figure it out, did your old alternator work? or do you still have the same issue?
yes it quit with the old alternator. Ran it about 15 min no issues. Checked amps betwen negative wire and post with 0 amps. I would look at your rectifier, mine had a plastic piece on it that caused the smoke.
Put the old back on it and checked for amp between all the wires at the alternator and between battery post and wire. Show zero on all of them, ran it for 15 minutes and no issues. Disconnected the the negative post, I will wait for better weather and drive it a bit before I feel comfortable leaving it hooked up. Took some pictures of the reman because someone asked me too. Thanks fr the suggestions.
Yep, your Stator winding's are smoked...
It also looks like the end bearing (needle bearings) has been pressed in really deep.
Just a really bad setup when it was rebuilt...
If you are handed a box of parts and told rebuild it, those are the parts you use...
My advice, put it back together and use it as a core if need be...
i haven't started the car yet,this smoke is just hooking the battery up and checking all the lights, etc, saw the smoke. maybe i got a bad rebuild also.
If everything else checks out, good alternator, etc., then what I am writing below could be the cause of no charging at the battery from the red charging wire. Do you have the factory ETR radio in your 82 or does it have a clock in the lower left hand gauge hole in the instrument cluster? If your car had the factory ETR radio, then it would have a oil temp gauge in the lower left hand gauge hole. This makes a difference on how your charging system is wired. The cars with the ETR radio and oil temp gauge has the charging wires, positive charging wire and ground wire, running just like you stated. They run from the back of the alternator down and through the frame, and come back out of the frame just at the back of the drivers side floor pan. When the red charging wire exits the frame, it then goes through the battery box fiberglass right by the left side of the battery and connects to a junction box. Picture below of the junction box. The black wire connected to the back of the alternator follows the frame route too but it comes out of the frame and grounds to a point on the rear crossmember. Here is the kicker, the red charging wire DOES HAVE a fusible link in it. It is right about where the red charging wire exits the frame or up in the frame. Simple to test it though, just unhook the red charging wire at the alternator and back at the junction box, use your multimeter to check for continuity. If the fusible link has been burned out then you will not have continuity on your charging wire. Below are some pictures of the harness and fusible link. The large rubber grommet is where the wire passing through the body into the battery box area.
If everything else checks out, good alternator, etc., then what I am writing below could be the cause of no charging at the battery from the red charging wire. Do you have the factory ETR radio in your 82 or does it have a clock in the lower left hand gauge hole in the instrument cluster? If your car had the factory ETR radio, then it would have a oil temp gauge in the lower left hand gauge hole. This makes a difference on how your charging system is wired. The cars with the ETR radio and oil temp gauge has the charging wires, positive charging wire and ground wire, running just like you stated. They run from the back of the alternator down and through the frame, and come back out of the frame just at the back of the drivers side floor pan. When the red charging wire exits the frame, it then goes through the battery box fiberglass right by the left side of the battery and connects to a junction box. Picture below of the junction box. The black wire connected to the back of the alternator follows the frame route too but it comes out of the frame and grounds to a point on the rear crossmember. Here is the kicker, the red charging wire DOES HAVE a fusible link in it. It is right about where the red charging wire exits the frame or up in the frame. Simple to test it though, just unhook the red charging wire at the alternator and back at the junction box, use your multimeter to check for continuity. If the fusible link has been burned out then you will not have continuity on your charging wire. Below are some pictures of the harness and fusible link. The large rubber grommet is where the wire passing through the body into the battery box area.
Thanks for the information, and yes i have the oil temp guage.
Alternator smoking
