Power roof vent problem.

Dirtydirt · 02-20-2021, 08:46 AM

Hello to all:
WE have a 2004 Vectra which has a power vent in the galley area. When I set the thermostat to off the fan runs. I figured the thermostat was wired backwards but upon investigating that makes no difference. With the thermostat removed and both wires disconnected the fan runs. The thermostat is set up when in the off position the contacts are open. Has any one experience this problem and found the problem. Thanks

Morich · 02-20-2021, 09:15 AM

Now that's interesting! Most of us can't get things to work and you want it to stop!!!
So which model 2004 Vectra do you have as there are about six and sorting through the drawings goes better/ quicker if we start on the right page?
For a quick question, do you know if there are more than one switch/location to turn this vent on/off? Something, perhaps like a room light that has two switches?

Dirtydirt · 02-20-2021, 03:42 PM

It is a WKS40KD I seem to always forget that detail. There is a switch to turn off the fan in the vent where is also three fan speeds I can select. However with the fan turned off in the vent area the cover will open with the thermostat in the off position. I’m not sure but yes I can’t get this thing stopped !!!!

Morich · 02-20-2021, 05:39 PM

I did some wire chasing and now it looks like it needs you to check a few things like if it is getting power to a wire at the vent as well as ground at the vent. Or checking first that the breaker is okay. Kind of your choice on which end to start, so I'll let you decide?

First thought might be to ask if both the bath and galley vents are not working right or is one working to show it is getting power and the other not? They share the same power and ground wires, so if one is working, we don't need to go to the breaker as it is the same for both.

If neither is working, check the breaker first, perhaps? That breaker should be at the 12 VDC panel where it looks like you have a top row and bottom row, where you need to carefully check the bottom row and fourth one from the left to make sure it is not tripped. Maybe push it once or twice to make sure it is staying in as it should.

Next thought would be to see that the power and ground are both good at the vent .
At the galley vent, you should find four wires and they should have codes along the wire sides, as in example picture below. A yellow wire labeled HHA should be the power from the breaker and near 12VDC with the white wire labeled HHB being the ground. If you can get to the vent wiring to check these, it will tell a lot. When checking be sure to check both the power and the ground as both as vital.

This is the "magic decoder" list for wires:
https://www.winnebago.com/Files/File...ical_guide.pdf

It may be as simple as one wire is corroded or broken off and something you may see but this is where I would start but it can also be something like one of the many connections that it goes through to get from the breaker to the vent.

If needed, that info and where the connections should be are available but often easier to check the things you know where to find like the vent!!!!

See if that helps any and let us know>>>>

Morich · 02-21-2021, 07:40 AM

Looking a bit further and reminding myself that you have a run problem, not a stop problem, the solution may be more likely in the wiring from the galley vent to the thermostat.
That wiring might be found at the galley vent and marked as GR and GS, so looking for any damage like being closed/mashed, in the mechanism may be the quicker way to go.
The thermostat is much the same as a simple on/off switch so if you look at the wiring for a complete circle/circuit from the vent to the thermostat and back when the thermostat is closed and then it should break the circuit when open.
Possible just the thermostat broken or damaged wires?

pobstlmo · 03-08-2021, 06:24 AM

I have the same fan, it’s the fan, I never did tear it apart to find the problem, but mine has the rain sensor and I believe it’s thinks it’s raining so it tries to close.
Mine is constantly opening and closing if I leave it in auto. One of these days I may disassemble it, probably an outdated broken circuit board, so I’ll be forced to buy a new fan.

jerichorick · 03-08-2021, 07:04 PM

Quote:

Originally Posted by Dirtydirt

It is a WKS40KD I seem to always forget that detail. There is a switch to turn off the fan in the vent where is also three fan speeds I can select. However with the fan turned off in the vent area the cover will open with the thermostat in the off position. I’m not sure but yes I can’t get this thing stopped !!!!

What I am about to say may seem a bit far out, but...
My fantastic fan was acting up. I pulled the fuse in the fan mount base and removed the screen/control mounting plate. Behind that is the control board. Moisture had rotted many of the foils and caused shorts and opens. I replaced the board and all was well again.

Over the many years I have been on the road I have found it is best to manually open the vent a crack. Humidity, especially in cool to cold temps, from simply living in the rig will get trapped in the vent box if it is not vented. When I replace the board I sprayed it with electrical water replant before I installed it just to help avoid damage if I forget to crack the vent.

Hope this is your problem. Easy fix.

Morich · 03-08-2021, 07:57 PM

Quote:

Originally Posted by jerichorick

What I am about to say may seem a bit far out, but...
My fantastic fan was acting up. I pulled the fuse in the fan mount base and removed the screen/control mounting plate. Behind that is the control board. Moisture had rotted many of the foils and caused shorts and opens. I replaced the board and all was well again.

Over the many years I have been on the road I have found it is best to manually open the vent a crack. Humidity, especially in cool to cold temps, from simply living in the rig will get trapped in the vent box if it is not vented. When I replace the board I sprayed it with electrical water replant before I installed it just to help avoid damage if I forget to crack the vent.

Hope this is your problem. Easy fix.

Yes, have to say a wet board or set of wires can do exactly as mentioned. The wires GR and GS as the wires which go to the thermostat, and that thermostat only works as if the two wires are touched together making contact for the circuit.

So if you have a point where those two wires are wet for a period of time, they can corrode together and stay in a ways that makes it appear that the thermostat has closed the contacts and that whole thing does make the fan turn on even when the thermostat is trying to turn it off. That's where they do need to look at the vents and wiring for something that is visibly wrong.

Testing for ground and battery is good to help locate a problem but looking for obvious things is still needed once to get it isolated. Wet boards need to be fixed even if they are not the current problem because they will be soon!