Black/grey drain valve stuck closed

[Yamero]

Hi folks,

My '05 Interstate has a single tank for combined black/grey use. Its drain valve got stuck recently. When I open the rear door and press on the drain switch, I can hear the solenoid click, but the valve remains shut. I inserted a broomstick about 3 feet into the drain pipe and tapped gently on the valve to see if I can loosen it. The valve would not dislodge itself through this method. I estimate the tank to be now approximately 7 gallons full, so I would not want to remove the drain pipe in order to gain access to the valve. Any suggestions?

Yamero

[richinny]

you can try warming it up with some hot water and add some valve lube. it looks like this is a new unit to you. did the valve work before?

[Protagonist]

Originally Posted by Yamero

Hi folks,

My '05 Interstate has a single tank for combined black/grey use. Its drain valve got stuck recently. When I open the rear door and press on the drain switch, I can hear the solenoid click, but the valve remains shut. I inserted a broomstick about 3 feet into the drain pipe and tapped gently on the valve to see if I can loosen it. The valve would not dislodge itself through this method. I estimate the tank to be now approximately 7 gallons full, so I would not want to remove the drain pipe in order to gain access to the valve. Any suggestions?

Yamero

Welcome to the AirForums!

The drain valve solenoid switch controls an electric motor that operates the valve. Any electric motor should have a fuse somewhere. If the fuse is blown, the solenoid switch will still try to activate the motor, but the motor won't activate. A quick download of the 2005 Interstate owner's manual tells me that the fuse is on Circuit 8, a red 10-amp fuse. The only other thing on that circuit is the holding tank heating pad, which you're probably not using now anyway.

Give that a try, and let us know if it works or not. If the fuse isn't the problem, we'll think of something else.

[Yamero]

Originally Posted by richinny

you can try warming it up with some hot water and add some valve lube. it looks like this is a new unit to you. did the valve work before?

I've owned it 2.5 years so far. The valve got stuck recently, perhaps a few months ago. How do you add valve lube? I'll also try your hot water treatment.

Thanks

[Yamero]

Originally Posted by Protagonist

Welcome to the AirForums!

The drain valve solenoid switch controls an electric motor that operates the valve. Any electric motor should have a fuse somewhere. If the fuse is blown, the solenoid switch will still try to activate the motor, but the motor won't activate. A quick download of the 2005 Interstate owner's manual tells me that the fuse is on Circuit 8, a red 10-amp fuse. The only other thing on that circuit is the holding tank heating pad, which you're probably not using now anyway.

Give that a try, and let us know if it works or not. If the fuse isn't the problem, we'll think of something else.

Thank you for your welcome message.
I looked at the 2005 Interstate owner's manual, and here's what its 12-volt circuit diagram show:
CIRCUIT 8, 10 AMP, RED
WASTE WATER TANK REMOTE DUMP VALVE
HOLDING TANK HEATING PAD
Correct me if I'm wrong, but doesn't the above circuit include the switch? My switch lights up and when I press it, I can hear the solenoid click. It appears that this is indicative of the 10-amp fuse being intact.
Here's another question. Suppose the switch and the solenoid are working, how do you electrically isolate the electrical motor? Incidentally, until you pointed it out, I did not know that there was an electrical motor to operate the valve. I imagined that an electromagnetic solenoid had a simple rod that pulled the valve to open, and a coil spring to close the valve. My Interstate is parked on my daughter's driveway in another town, but I will go and see it this weekend. I will update y'all on any new findings.

Yamero

[richinny]

the lube is added down the toilet. i don't know if it will seep through to the valve but it will help if you get it moving. stuff in the tank can dry pretty hard if not flushed or used in a while.

[Protagonist]

Originally Posted by Yamero

Thank you for your welcome message.
I looked at the 2005 Interstate owner's manual, and here's what its 12-volt circuit diagram show:
CIRCUIT 8, 10 AMP, RED
WASTE WATER TANK REMOTE DUMP VALVE
HOLDING TANK HEATING PAD
Correct me if I'm wrong, but doesn't the above circuit include the switch?

Depends on how it's laid out. If it's a direct-acting switch, it's on the same circuit. If it's a solenoid, then the switch is wired separately from the motor it controls. Since you said you heard the solenoid clicking when you flipped the switch, I assumed it's a solenoid and therefore wired separately from the motor itself.

In any event, one of the key rules of troubleshooting is "check the easy things first." A fuse is easy to check, cheap and easy to replace, and if the fuse wasn't the problem, you've only lost a few minutes. Whenever there's an electrical problem on the DC side, my first action is always, "check the fuse." On the AC side, it's "check the circuit breaker," which is really the same step.

On edit…

The motor that drives the valve should be on the outside of the tank, and accessible for maintenance. If the motor isn't functioning, you'll want to remove the fuse before working on the motor, for safety, even if the fuse wasn't the problem. Removing the fuse is part of an electrical safety procedure called "lock out/tag-out" and is meant to keep you from getting an electric shock while working on electrical components.

[Ag&Au]

Originally Posted by Protagonist

.................................................. ......

Removing the fuse is part of an electrical safety procedure called "lock out/tag-out" and is meant to keep you from getting an electric shock while working on electrical components.

It also keeps the fuse from blowing or other more substantial damage occurring if one of the wires comes into contact with the system ground, which in this case may be anything metal in the vicinity.

Ken

[avanti]

IIRC, those valves have a feature by which they can be opened and closed manually using a screwdriver. You of course will have to crawl under the vehicle to do this.

[overlander63]

I have been bit several times before with a bad/corroded/loose ground. I would check that here, especially on something that goes down the road and has muddy, cruddy water splashed on it while driving.

[avanti]

From the 2005 Interstate owner's manual:

There is a manual override for the electric system for the electric valve located on each side of the valve. It is flat head screw that is turned clockwise or counter clockwise according to side you access to open and close the valve. The direction is labeled on the valve.