Help please - Bilge Pump - Maxum Boat Owners Club

td6837689 · 05-31-2016, 01:28 PM

Hi all, when getting the boat ready (after a long winter) for first launch of the year I found my bilge pump not working (1800 MX). Its a manual pump. When switched on at dash, nothing...checked the under-dash fuses, all good there (although not sure if pump runs off one of these fuses).
So, any suggestions on what to try next to determine its state? And if I need to replace, what's the best way to remove/install? It appears to be in quite an inaccessible place, where working on it requires feel, no sight...?
thanks in advance for your guidance

Woodcorey · 05-31-2016, 02:22 PM

Following as I have a similar problem. I have 1800 SR3 with an automatic bilge pump that was not operable first weekend out. I did not realize it was not working until it had water in it. Both the inline fuse on the battery and under dash kept blowing. Pulled it out in hopes that drying the pump would help.
Any ideas?

shrew · 05-31-2016, 03:56 PM

Welcome aboard td6837689 and Woodcorey. So, already we have two different issues which happen to be related to bilge pumps. One is blowing fuses and the other is not.

Typically, hijacking someone else's thread is frowned upon.

If fuses are blowing then the connections to the pump need to be inspected and, more than likely, the pump needs replacement. Fuses blowing indicate draw. The corrosion is probably on the common ground side. The pump will typically have a dedicated hot from the battery switch and another from the switch at the helm. The dedicated hot is to the float switch. If both are blowing it is probably corrosion on the negative side or the pump.

remove the pump, cut back the wires, use new MARINE butt connectors and shrink tubing.

For the pump which is NOT blowing fuses, start with VoltMeter at the pump itself. You can also use a voltmeter on the switch. Make sure you're getting power to the pump and to the switch.

Bilge pumps are not inaccessible. There is a way in there.

mmwjr · 05-31-2016, 04:00 PM

Use a volt meter to measure for 12V at the helm switch, should be on both terminals when the switch is on.

You can also cut the wires to the pump and directly wire it to the battery to see if it runs. If it runs the issue is else where in the wiring. If it does not run the pump is bad.

Woodcorey · 05-31-2016, 04:02 PM

Thanks for the quick reply and apologies for hijacking.

shrew · 06-01-2016, 01:51 PM

Quote:

Originally Posted by mmwjr

You can also cut the wires to the pump and directly wire it to the battery to see if it runs. If it runs the issue is else where in the wiring. If it does not run the pump is bad.

I'm not sure how I overlooked this one. This is one of my most frequently used troubleshooting steps, and often one of the earlier steps in the process. It will verify whether the device itself is working. This is a good baseline to work from. It doesn't matter how much testing you do if the device is dead.

I guess i the case of the fuses getting blown, we know the device is working and the circuit is getting closed somewhat properly.

td6837689 · 06-01-2016, 02:14 PM

Thanks for the suggestions. Just one more thing...I would assume that the pump is accessible is some way. I suspect its attached to the bottom of the engine (Mercruiser 4 cyl) and its easy to get off...perhaps its slides out of brackets or it needs a twist to break free from whatever is holding it. Can anyone confirm?
thanks again

mmwjr · 06-01-2016, 02:18 PM

The pumps base is screwed into the hull and the pump either twists in or snaps on. What brand is the pump of can you post a picture?

td6837689 · 06-01-2016, 05:13 PM

Quote:

Originally Posted by mmwjr

The pumps base is screwed into the hull and the pump either twists in or snaps on. What brand is the pump of can you post a picture?

I'll post a pic this weekend...but I'm positive its attached to the underside of the engine...I felt it there and am certain there was a space gap between the pump and the hull. I'll feel around in there and hopefully it detaches without too much (back) pain...thx

shrew · 06-02-2016, 04:04 PM

I believe that it might be located Beneath/Under/Below the engine. However, it is most assuredly not attached TO the engine. There is a space/gap between the bottom of the oil pan and the hull.

The easiest way to locate the bilge pump would be to locate the discharge throughhull and follow the discharge line.

td6837689 · 06-07-2016, 03:14 AM

quick update: I took out the pump and there was fine hair (fishing line, perhaps) wrapped around the spindle. I suspect this clog may have blown the fuse. I cleaned it up, re-installed...all good. One word of advice through this ordeal...make sure your fuses are good. It was the first place I looked, and the fuse looked fine (it wasn't). I even replaced it with the spare in the fuse box; it also looked ok (it wasn't). Finally tried a fuse I knew was good (took it from my snowmobile), and voila.
Thanks for all the suggestions, lads...

lug · 06-21-2016, 09:27 AM

I used this thread to replace my bilge pump, thanks.