View Full Version : Johnson Reversible pump issue - blow fuse

08-01-2012, 08:50 PM
Ok I am having an issue with my Johnson pump blowing my fuse. This has happened three times.

My Setup:
From the power block I come off to a 20AMP fuse. One for each pump. for a total of three fuses for the pumps. I have a switch for each pump. Then from the switches two wires for each pump back to the pumps.

The Issue:
When I turn on my center switch I blow the fuse.

Testing: NOTE All testing was done on land without water going to pumps.
Replaced fuse and blew it again. It is almost instant that the fuse is blown.

Pulled the wires at the pumps and swapped the center pump for port side pump. (Seeing if it follows the switch or the pump). Center switch will work the port pump no issues. Port switch blows fuse on center pump. (Issue followed pump)

Switched back to make sure Center switch still blows fuse when connected to center pump. (It does)
Port switch powers port pump no issues.

pulled the impeller casing off the impeller and was able to spin impeller no issue on Center pump.
Pulled impeller from pump.

Turned on Center switch to Center pump without impeller. No issue.
reinstalled impeller and turned on Center pump again. No Issue.
reinstalled cover to impeller housing and turned on Center pump. No issue.

Now to the Question. When i get her wet again am I going to blow a fuse or what? Is it too much pressure having water in the lines? The other two pumps fill end empty no issue. Same thru hall for all three pumps. Ideas?

08-01-2012, 09:58 PM
Sounds like a sticking impeller. Next time you are done for the day and have completed the final drain cycle, flip the switch to the fill direction for 5-10 seconds. This flips the impeller to the fill direction for the next time out. It takes less current to un stick an impeller that's been sitting if its already rotated to the right direction.

08-02-2012, 09:03 AM
Mike for what its worth i run 25 amp fuses, 20 amps is cutting it pretty close, there is a spike in the amperage when you turn them on. I carry plenty of fuses and blow them from time to time. Not much you can do.

MLA is right i think it prolly an impeller sticking issue.

Mike did you have any G ballast when the boat was new? If so did you run all new wires from the fuse block under the dash to your ballast switches? I know my factory GIII has a fuse for each pump but at the switches they used this daisy chain method to power and ground them to each other.

You could on a rare chance have a bad switch as well, but sounds like you moved the pump and the fuse blowing followed it. So id say its the pump sticking a little or it might just be drawing a slightly higher amperage then 20

08-02-2012, 11:05 AM
I ran new wires. Did not like what came with the GI system. I will replace them with 25 amp fuses if I blow another 20 amp. The thing is it is only that one center pump. I have not had any issues with the other two that are setup the same way. Also that sticking makes since. I will make sure I put a little water back in the lines after I empty. Thank for the help.