Here's a general approach, but always consult your vehicle's owner's manual for the specific location and removal instructions for your E350. Improper removal can damage wiring or the battery itself.
Before You Begin:
* Safety First: Wear safety glasses and gloves. Batteries contain corrosive acid.
* Disconnect the Battery: Always disconnect the negative (-) terminal *first*, then the positive (+) terminal. Use a wrench appropriate for the terminal size.
* Ventilation: Work in a well-ventilated area. Battery fumes are hazardous.
General Removal Steps (Adapt as needed):
1. Locate the Battery: This is the crucial first step. The auxiliary battery might be under the hood (though less likely), in the rear compartment (common in camper vans), or even under a seat or in a dedicated battery box. Consult your owner's manual or check online forums specific to your year and model.
2. Access the Battery: You may need to remove panels, covers, or other components to reach the battery. Take photos as you go to aid in reassembly.
3. Disconnect the Cables: As mentioned above, disconnect the negative (-) terminal first, then the positive (+). Note how the cables are routed and connected.
4. Secure the Battery: Depending on how it's mounted, you may need to loosen bolts, clamps, or straps holding it in place. Carefully remove the battery. It might be heavy, so get help if needed.
5. Clean the Area: Clean any spilled battery acid with a baking soda and water solution. Neutralize the acid before cleaning up.
Important Considerations:
* Battery Type: The auxiliary battery might be a different type (AGM, deep-cycle, etc.) than the main starting battery. Handle it accordingly.
* Wiring: Take note of any wiring connected to the auxiliary battery. If you're unsure about anything, consult a professional.
* Grounding: Make sure the ground connection is properly secured when you reinstall the battery (if applicable).
If you are unsure about any step, it's best to take your E350 to a qualified mechanic. Improper battery handling can lead to injury or damage to your vehicle's electrical system.
