[czarcone]

Sounds familiar, prior to launch I flipped the switch & blower runs for 30 secs, then trips breaker.  Reset & runs for another 30 secs.   When I get to slip, I take a look & find two blowers, one behind the other.  I was able to get direct replacements ( Jabsco #36740 series).  No telling how long the one blower has been seized & rusted open.  Pretty straight forward replacement except for the extremely inhospitable location.  I had to lay on my back across port engine & work upside down in order to manipulate hose clamps, wiring & mounting screws.  Hoping to not look at them again for another 20 years! 

If motors are the same, they each draw 6.8 amps.  Next year I'll attempt to tackle that cracked sanitation hose.  Good luck!