perplexing one-way problem on Jabsco pumps

[vision]

Originally Posted by c640947

I do not believe it is the check valves (good thought though) as the pump does not turn on. Check valve issue would be pump is on but not moving water i think.

Agreed.

Since all 3 pumps are affected, both directions, and it comes and goes, I vote the ground or power wire to your relay box is loose. All three relays (I believe the 06 has no timers but does have relays) likely run off of a single power wire and ground wire from the battery on/off switch to the relay box. Make sure to check both ends of the power and ground wires to the relays and good luck.

[Thrall]

I think the OP said they are only affected in one direction, all 3.
Still, I'd look into the relays. I believe the 06 has 2 relays for each pump. 1 fill, 1 empty.
Not likely, but possible that wires got unplugged at the switches. Had that happen to one wire on mine.
Swap relays around to test if they're bad. Look at all connections.

[Thrall]

Originally Posted by Smoothie

@Thrall. How do you flip the pumps? I have heard people running the wires opposite. Black Ground to Red and Red to Black Ground. That way you can flip the pump and it will fill and empty properly according to your switches.

WHen you flip the pumps, take the pump head off and rotate it 180 deg. I did not do this, but learned of it later (on TMC here). That will get the correct rotation wrt the switches without cutting wires. Right now mine is fill=empty on the switches because the switches looked like a pain to flip, wires all tightly bundled. I'll spin the pump heads next time I need to tear into the impellers, which by the way if flipped, the rear impellers are harder to access.
The rear pumps can be flipped without doing anything to the hoses, but they need to be mounted lower with only 2 of the screws. WOrks fine since the hoses pretty much hold the pumps in place anyway.

[swatguy]

I can't recall what year mc switched from the black plate switches to the silver toggles. If you have the black switches its simple to swap the rotation to match. Pop the switch plate of. Next pop the guts/electrical housing out of the dash and rotate it 90 degrees. Snap it back in, snap the switch plate back on viola. The plates just pop off it may seem like they don't but just pop me off with flat head from the center.

Also you say they work in one direction. What direction is that? The pumps have a safety system on them to prevent burnout. If you suck air for a bit too long the pump will go into a sort of protect mode. Usually if it's a fill problem and the empty works fine it's a check valve issue not sealing to suck air. pretty sure the 06 emptied above the waterline. If not disregard next process. Next time you fill put your hand over the empty line. If you get a suction pulling on you palm it's a bad check valve. Also if it's a fill issue and you are sucking air try filling while under way at around 15 mph or so.

[Smoothie]

why is it a problem just to switch the wires where the pump is?

[Granite_33]

In terms of amps / volts the pump actually sees, you might want to start with that first. Voltage going from the battery, through a switch, through smaller wires and to the pump could see a significant drop in voltage.

It makes sense that your pumps would run no problem straight from the battery, there is essentially no voltage drop.

In terms of current needed by the motor when running, the motor does not require too much. However in terms of locked rotor current, the level of amps needed to break the rotor loose (impeller vanes inside the pump housing) can be up to 10 times higher. (thats why your lights dim when your A/C unit starts up)

The motors in these pumps dont have much giddy up in them to help them from a dead stop. Any degradation in the power supply simply will not break the rotor loose (pump vanes) and the pump will remain locked up.

When my factory impellers failed, I went to install new ones and took note of the very small wire running from the ballast switch to the pumps themselves. Think of the wire as a hose. The bigger the wire, the more current that can pass through them.

In terms of the pumps starting in one rotation but not the other, that may be a factor of where the rubber vanes are and in which direction they are pointed. Breaking them loose when they are pointed in the wrong direction requires more starting current.

Good luck with it.

[c640947]

UPDATE

So I found a post that point to the problem being the relays:

http://www.mastercraft.com/teamtalk/...ad.php?t=43365

and another referenced post that discusses the relays:

http://www.mastercraft.com/teamtalk/...ad.php?t=40934

When I took off the relay / fuse box and laid it on its side, all pumps worked in both directions. So I am thinking the relays are old and got stuck. They would get stuck again and hitting the relay with a wrench solved the problem. I have ordered new relays from here:

http://www.ase-supply.com/87411_MINI...p/hl-87411.htm

I will put them in and see if that finally solves the problem. Just wanted to update any future folks with the same problem.

odd that the wires to the pump were getting proper voltages yet if they ran was dictated by the relays. I guess I don't understand the purpose of the relays...

[Philscbx]

That's great is finally solved.

High load devices need relays using full battery power / triggered by small wire & load switches at long distance.
Picture the main battery & switches sitting next to pump.
If switches can handle the load of the pumps - fine.

But that's not the case - switches have very low load ability in that amp range.
They would get hot & melt.
You could use phone cable as the trigger voltage to the relays & relays would have the 10G wire to run the pumps.
Of course - the relay's main power source would also need 10G wire from battery.

Similar to key switch to starter - it can be any distance from starter - it's just the trigger voltage going there.