alternator heating up

[1972 searay]

I have a 1972 sea ray with 165 mercruisers. the starboard alternator got very hot today. the battery was almost dead. barely able to start engine.
Is this the cause of the excessive heat? the voltage meter on the console showed high amps being generated by the alternator.

thanks in advance for the imput.

 

[Don S]

Re: alternator heating up

They do get hot when at full charge. It's normal.

 

[Mischief Managed]

Re: alternator heating up

You are right, the excessive current draw heated up the alternator. Could be a short that's doing it and killing the battery, or it could be a short in the battery itself. If you have two batteries, swap them and see if the problem follows the battery or not.

 

[Bt Doctur]

Re: alternator heating up

If your is identical to mine you have the GM 1 wire alt.
If your batteries are in good condition and you start the motors ,the charge rate will be up there 5-10 minutes and then start dropping down toward the center of the gauge.If you see a constant hi charge rate it could be a internal short in the battery . The GM 1 wire dosent usually go "wild" in charge rate

 

[1972 searay]

Re: alternator heating up

thanks, the battery was really low. after about 20 minutes of running on the starboard engine i put it on the port engine and that alternator stayed pretty cool. alternator has a red wire and black wire together with another grounded directly to the engine block.