Brand new alternator, super hot to the touch

[KetchiMan]

2004 Merc 5.0L MPI, Bravo 3 outdrive in a Trophy 2359
Just put in a brand new alternator (old one got seawater in it when the water pump went out) and it immediately got super hot to the touch. Might also be putting out higher voltage than the old one. Is this a problem with the alternator itself? Is there a separate voltage regulator? Voltage regulator built into the alternator? Any other reason it would get hot????

Thanks,
-Nick

 

[Scott Danforth]

Could be a bad connection on the voltage sensing terminal ( I terminal) could be a bad bearing,or the belt is too tight.

 

[GA_Boater]

2004 Merc 5.0L MPI, Bravo 3 outdrive in a Trophy 2359
Just put in a brand new alternator (old one got seawater in it when the water pump went out) and it immediately got super hot to the touch. Might also be putting out higher voltage than the old one. Is this a problem with the alternator itself? Is there a separate voltage regulator? Voltage regulator built into the alternator? Any other reason it would get hot????

Thanks,
-Nick

Nick - Anything else get seawatered? There may be water induced corrosion on the wiring/connections causing high current draw.

 

[KetchiMan]

Nick - Anything else get seawatered? There may be water induced corrosion on the wiring/connections causing high current draw.

Most of the seawater got sprayed around in the plane of the pulleys. I immediately rinsed everything off really thoroughly, but I did just have to replace the 90 amp fuse at the starter.

 

[gm280]

Most of the seawater got sprayed around in the plane of the pulleys. I immediately rinsed everything off really thoroughly, but I did just have to replace the 90 amp fuse at the starter.

One way to determine if it is bearings or such is to disconnect the alternator completely and run the engine to see if it still gets hot. If so, it is not the electrical components in the alternator. Still could be bearings but the eletrical circuits would be out of the circits that way. If it doesn't get hot, you have electrical issue with it or the wires going to it. JMHO

 

[achris]

Put your battery on a (external) charger and make sure it's fully charger. Then check your alternator temperature. Also see if you can get an ammeter that just fits on the wire to give you an idea of the output current.

An Ammeter like this.