The picture below shows the interior chassis fuse and circuit breaker panel. I copied it from the 2009 Sightseer operator manual, page 3-13, for which I provided a link in my post #7. A quick look at the floor/wall to the left of the driver's seat should confirm if your coach has that panel. If it does, then the Ford fuse box is in the upper section of the panel.
By the way, there are two Ford fuse boxes on your coach. The first, called the "Power Distribution Box," is under the hood, above the radiator, attached to the firewall. The second, called the "Passenger Compartment Fuse Panel," is in the interior, attached to that Winnebago panel as shown in the picture below. You can download the Ford manual for your coach at this link
. (You enter the model year of the chassis, then "Ford," then "F-53 Motorhome Chassis"). For a 2008 chassis, the manual is here
, and for a 2009 chassis, the manual is here
. The fuse sections of the manual starts on page 62 (for 2008) and page 69 (for 2009). Note: It's possible your 2009 coach is built on a 2008 chassis.
On to the wiring diagrams for your coach (link here
). You may not have known it when you bought the coach, but 2009 was one of the last years Winnebago provided a full set of diagrams. You have two choices: Download the entire set as a "Complete Wiring Diagram Book (701674-78-022)
," or download the diagrams individually. If the latter, you will need a copy of the Wiring Identification Guide
, which is included in the book, to study the circuit designators, such as "DY." I call the Guide the "secret decoder ring," a term that gives away my age.
For the defrost fans, look at the Automotive Wiring Diagram
1) Fans shown on sheet 1, zones D-20 and D-21. Circuits "LE" and "LF" are the 12V power circuits, "XW" the grounds, per the Guide:
CODE / COLOR FROM: TO:
LD / 14 YEL IGNITION SWITCH ACCESSORY POWER SOURCE GENERAL PURPOSE(AUX FANS,RELAY TRIGGER,ETC.)
LE / 14 YEL AUXILIARY DEFROST FANS SWITCH (HIGH SPEED) AUXILIARY DEFROST FANS (BLK)
LF / 14 YEL AUXILIARY DEFROST FANS SWITCH (LOW SPEED) AUXILIARY DEFROST FANS (RED)
XW / 14 WHT IGNITION SWITCH ACCESSORY FEED RELAY CIRCUIT GROUND
2) "LE" and "LF" go to a 6-pin connector on the same sheet, zone D-19.
3) A note above the connector sends you to sheet 3, zone A-4.
4) On sheet 3, zone A-4 the DEFROST FANS SWITCH has three leads: "LD," "LE" and "LF." That means "LD" is the 12V input to the switch. And "LD" leads to the same 6-pin connector. So, off to sheet 1, zone D-19 again.
5) From the 6-pin connector, we follow "LD" down and to the right, and "up" until we find its source. Along the way, we see that "LD" feeds components, in addition to the defrost fans:
a) a 15-pin connector in zone A-18 (RADIO POWER SWITCH)
b) a 3-pin connector in zone D-11 (REAR MONITOR)
c) the POWER MIRRORS RELAY in zone A-10
d) a 3-pin connector in zone A-5 (HWH - possibly the jack system)
We finally find the source in zone D-2. It's a Ford 16-pin connector. The drawing says the function is ACCESSORY FEED #1 ACC & RUN.
... and finally, you will find that feed on the Ford Passenger Compartment Fuse Panel layout (links above), on fuse #5.
Since "LD" feeds many items, it is possible that if the fuse is blown, its replacement will cause other things besides the defrost fans to start working correctly again.
As I said in post #7, let's start with the fans and their fuse. If you can fix that, you can move onto the other problems that may remain.