Certain items don’t work when on chassis power

[Scottew]

I have a 2011 Winnebago Journey Express. Both the front windshield shades don’t work...unless I have been driving for awhile and then they magically come to life. To add to the confusion the dash radio and navigation system only works on coach battery mode (switch on the dash) the door lock doesn’t work either. I feel like it is a connection problem as I checked all the fuses I can find. Any ideas?

Things I considered:
chassis batteries? They crank up the engine every time so...
fuses? Checked them all I can find including downloading wiring schematics.
radio connection issue? Then why the shades?
ignition switch? Went under dash and the connection is solid.
The clash has only 18,000 miles on it so has little wear.

 

[Frank B]

I have a 2011 Winnebago Journey Express. Both the front windshield shades don’t work...unless I have been driving for awhile and then they magically come to life. To add to the confusion the dash radio and navigation system only works on coach battery mode (switch on the dash) the door lock doesn’t work either. I feel like it is a connection problem as I checked all the fuses I can find. Any ideas?

Things I considered:
chassis batteries? They crank up the engine every time so...
fuses? Checked them all I can find including downloading wiring schematics.
radio connection issue? Then why the shades?
ignition switch? Went under dash and the connection is solid.
The clash has only 18,000 miles on it so has little wear.

The intermittent connection to the window shades that works after driving a while (i.e. some movement and vibration) sounds like a bad ground somewhere. Especially because it is 10 years old, and you are in Florida with all that moisture and salt spray off the gulf. Does that circuit have just ONE ground point? Or even a chassis or inline plug in the wiring harness that has some corrosion in it? A corroded chassis plug could cause several seemingly unrelated issues.

 

[Scottew]

The coach just came out of a garage storage unit. Was up north. I couldn’t find any corrosion anywhere. I checked ground wires but haven’t confirmed that I found all of them.

 

[Frank B]

The coach just came out of a garage storage unit. Was up north. I couldn’t find any corrosion anywhere. I checked ground wires but haven’t confirmed that I found all of them.

You say that you downloaded a wiring diagram. Do/does this/these show where the chassis connectors are? Does the wiring for any or all of the affected systems go through a single chassis connector?

Its been too long since I had a good look at anything like this, but unless anyone else comes up with a better idea, I think you have a nasty job ahead of you.

Chassis connectors are multi-pin 'weatherproof' connectors that go through the bodywork from one side of the firewall to the other. These need to be separated and inspected for corrosion. I doubt it will be possible to detect corrosion visually without separating the two halves and actually having a look. They don't usually put these connectors in easily accessible places.