In-line fuse to aft bilge pump (1996 2855 7.4 liter Mercruiser)???-gctid406342

[Guest]

My aft bilge pump was siezed. Manually turning it on would immediately blow the fuse behind the dash. I replaced the bilge pump and it works fine when manually triggered. The bilge pump didn;t work when I put water in the bilge to test the float switch.

I assumed the float switch was bad, too, and just spent this evening replacing it. When I manually trigger the new float switch, still no bilge pump. Then it hit me: is there an in-line fuse going to the float switch? If so, it would have blown trying to trigger the old siezed bilge pump. It was getting dark and I was beat, a cursory look didn't show any in-line fuses.

Do any of you know if there's an in-line fuse between the battery and the float switch, and if so where it would be/what it looks like? Thanks in advance!

Rob

[Guest]

The float switch is wired from power to the hot side (brown wire) of the pump so there shouldn't be another fuse unless someone wired one in somewhere along the run of wire but not likely since it works manually. With the switch in the on position it should turn the pump on when you lift the float. So my question at this point is; how do you have this wired?

Someone smarter than me is going to tell you it should be powered directly and not be dependent on you remembering to flip the switch to supply power.:arr

[Guest]

I just downloaded the Owners Manual (they call it a supplement, but it's the owners manual that I didn't get when I bought my boat used) from www.baylinercustomercare.com. There is an in-line fuse, located at the "main battery switch" which I suppose is the MBSS. Of course I was hunting all around the batteries themselves. I'll track it down tonight, and with any luck I will have functioning bilge pumps on a float switch. I suppose it was a good thing to replace the 16-year-old float switch anyhow, right?

In searching this site I noticed a year-old thread describing the weak design decision to have both bilge pumps (aft- and mid-cabin) feeding through the same in-line fuse. One pump blows the fuse, and neither pump will work. There's a project for another day....

Rob

[Guest]

I have never seen a second fuse on the bilge pump. It sounds like a wiring issue. The connection is usually made right at the floatswitch and pump so it should be easy to trace.

[Guest]

Hey Rob - Just saw the thread about your aft bilge pump problem and wondered if you ever did find a separate in-line fuse. Having similar problem on my 95 2859 where aft pump just would not work. Checked switch on dash and fuse behind dash but could not get power to the pump. Forward pump is fine. Had to rewire aft pump directly to battery and it now works off float switch only. Thanx, Capt Dick

[Guest]

Hi Dick (and any other interested parties). On my 2855 the actual wiring is as follows. The aft bilge pump is hard-wired to one battery, with an in-line 7.5 amp fuse located just under the MBSS. The mid bilge pump is wired to the other battery with an in-line 7.5 amp fuse.

Each bilge pump also has a manual switch at the helm to turn them on, and each of those switches has a blade fuse under the dash. This is not as described in the owners manual, but the wiring appears to be stock to me. The owners manual appears to be generic over multiple years and models.

I hope this helps you!

Rob

[Guest]

Hi Rob - Just saw your earlier reply and hate to show my ignorance but what does "MBSS" stand for? Thanx again, Capt Dick