open under hood fuse box

On our 2002 E450, cover is rectangular, long edge parallel to bumper. It's hinged on the outboard (driver fender) end. On the INBOARD end, there' a little catch on each side of the long edges, right where they meet the short inboard end. Easy one to feel is between the brake fluid reservoir on the master cylinder, and the coolant reservoir tank. Opposite that, on the forward edge of the cover, is a matching catch. They only need to be pulled outward at the bottom edges to let go of the box and allow you to lift the cover. Then you can un-hinge it on the outboard end. Should be a legend inside of what's what.

hilcntry,

I would suspect that if you shorted the wires coming from the house battery, that you blew a fuse near the house battery. When you say that everything is dead, do you mean the house part or the vehicle part of your camper?

William

j-d wrote:
On our 2002 E450, cover is rectangular, long edge parallel to bumper. It's hinged on the outboard (driver fender) end. On the INBOARD end, there' a little catch on each side of the long edges, right where they meet the short inboard end. Easy one to feel is between the brake fluid reservoir on the master cylinder, and the coolant reservoir tank. Opposite that, on the forward edge of the cover, is a matching catch. They only need to be pulled outward at the bottom edges to let go of the box and allow you to lift the cover. Then you can un-hinge it on the outboard end. Should be a legend inside of what's what.

Exactly the same on 2004 E350.

It should be impossible to hurt anything at the engine when installing the house battery, particularly if the engine was not running so the house was not connected to engine power. Do you mean the engine now doesn't start? Or no power to the house from the house batteries? Both?

I'm not sure the answer to OP's problem is in the chassis fusebox either, but at least he should now be able to get it open.

Would like to know more about "shorted out the house battery." Most of all, I hope the battery-to-coach polarity wasn't reversed. A "short" in automotive usually means the Hot got Grounded, or something in the Hot (like a switch or relay) was bypassed to get a circuit tested or working temporarily.

Reversed Polarity would mean Hot and Ground got reversed. For example the battery cables! If Hot and Ground got reversed, some component like the Converter or anything with a logic board is likely to be damaged. Sometimes there's not just one Hot and one Ground cable at the Battery, so only one needs to be mis-connected to cause problems.

And "Everything dead..." Whole RV? Chassis headlights? Horn won't blow? I find it hard to believe that a House issue killed the Chassis?

Find the House Battery Relay. The one that clicks when you turn the Battery Switch on/off. Some would call it a Solenoid and with a Ford chassis you should see the OEM CHASSIS Starter Relay/Solenoid in the inner passenger side of the engine compartment. Little round guy with two heavy cables held by nuts, and a couple small control wires. Well, two more in a Class C. One is Start Assist. Pushing it connects House and Chassis batteries for emergency jump start. NOT that one. The Third One disconnects HOUSE battery so it doesn't get run down in storage. Find that and see if there's a fuse to its control wiring, and/or a Fuse or Breaker nearby for its input/output.

Our small C just uses the built in Ford trailer battery charging system, which is a fuse and relay in the engine fuse box, looking like all the others in there. It's a 40 amp fuse and relay E.
In this picture I have replaced the relay with a wire to chart the engine battery from the house solar.

In the case of a house battery connected to it, the fuse would blow for sure.