Over Heating Alternator??

I am in the middle of a major overhaul of my 1999 TD5 Defender, and it seems my alternator is over heating.

Any ideas why???

inside dirty or bearing getting ready to pack it in or over charging

Thor1950 said:

inside dirty or bearing getting ready to pack it in or over charging

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If I put a volt meter on the terminals when the engine is running, should I be able to see if it is over charging???

How do you know it's over heating ??

Carrington224 said:

How do you know it's over heating ??

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Because its really hot!!

I have just measured the amps that the alternator is putting out, and it is averaging about 80. I have been told, that it should be around 20 so the problem seems to be it is over charging.
Bugger.

Uphillphil said:

I have just measured the amps that the alternator is putting out, and it is averaging about 80. I have been told, that it should be around 20 so the problem seems to be it is over charging.
Bugger.

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The amps will change depending on the draw on the alternator, surely.

Have you checked your battery? If the battery is goosed, it'll be putting more strain on the alternator. Likewise if you've got a high draw on it, it'll be putting more work in.

It's a brand new 95Ah battery.

So next thing to do is check the voltage of battery, if it's full )13.2 volts with engine off, you should look if there's anything else that could be drawing power.

Just another point............
The Defender is a Special Vehicles version, and has a split charging system. I am only using 1 battery at present............Could this have anything to do with it???

Uphillphil said:

Just another point............
The Defender is a Special Vehicles version, and has a split charging system. I am only using 1 battery at present............Could this have anything to do with it???

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Where are the cables that would normally go on to the second battery? I would imagine if you insualted the metal well, it should be fine. If they're touching or touching the chassis etc, you've got an electrical fire waiting to happen and a high draw

Thanks for your input. I really appreciate it.
The wires have been disconnected, so no chance of shorting. I have just been up and tested the battery which is fine. It seems next stop is to remove the alternator, and have a look at it.

Check your earths!

A bad earth will cause the alternator to overheat!

Uphillphil said:

I have just measured the amps that the alternator is putting out, and it is averaging about 80. I have been told, that it should be around 20 so the problem seems to be it is over charging.
Bugger.

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How did you measure that?

Most run if the mill multimeters can only measure up to 5A max

As others have said a bad earth will put a lot of strain on an alternator