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1983 Cadillac Coupe DeVille
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6 Posts
Discussion Starter #1
I recently took my '83 Caddy to an ÁmeriCARna' event here in New Zealand and
noticed after the long drive there, the 'no charge' light showing, revving it a little
and would go off until it got to staying on continuously. It seems to start fine when
cool but battery seems weak when hot, it does still start tho. I have tightened all
the belts as I've recently just put a new water pump in. It now glows bright when
idling but fades a little with revs. I've noticed alternator gets quite hot to touch
after 5 minutes of revving. Really need some help as I'm just a grandma and not
sure if my alternator is buggered or something else. Any help would be really
appreciated. It has the 4.1 motor.
 

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96 Fleetwood, 94 Fleetwood, 07 CTS, & 94 Caprice Wgn
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637 Posts
Hey Gramma

Been a while since of been into alternators of that vintage. It could be the "diode bridge" or brushes. Both are readily available at auto stores in the states, but I guess you could start with auto parts stores in New Zealand. Easy and inexpensive fix, if that's the problem.

Grampa Tom
 

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1980 FBC
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980 Posts
If the alternator gets hot quickly it could also be a shorted rectifier diode.

Do auto parts stores there bench test alternators?

Best of luck!
 

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1983 Cadillac Coupe DeVille
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6 Posts
Discussion Starter #5
Yes I can get it bench tested here. I'm guessing I'm going to have to remove it and have it repaired or replaced. Would it be right to say it is an alternator problem tho? It did seem very hot after running the engine for about 4 minutes. Thanks for advice
 

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1980 FBC
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980 Posts
Hot after 4 minutes AND idiot lamp along with sluggish battery is most likely a bad rectifier diode.

Usually an alternator with this problem still makes power but it can only deliver about 1/3rd of its normal rating while dragging on the belt and engine as if it were working fine.

A competent bench test will tell all.

Another thing to look out for is the A.I.R. pump belt can slip on your car. This belt drives the water pump stepup pulley. HOT alternator indicates this is not the root cause of your troubles.
 

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1983 Cadillac Coupe DeVille
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6 Posts
Discussion Starter #7
Hey thank you :) your information has helped me with alot more to check for. I've done about 250 miles since putting in a new water pump so am going to check all the belts as well. Thank you.
 
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