Inspection and Verification

WARNING: This page is about a different car, the 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

Refer to Customer Access for schematic and connector information.

It will be necessary to refer to upfitter documentation a for additional wiring information.

Diagnostics in this article assume a certain skill level and knowledge of Ford-specific diagnostic practices. REFER to: Diagnostic Methods .

Verify the customer concern.
Not all auxiliary switches may be used by upfitter. Confirm the auxiliary switches that are used.
Visually inspect for obvious signs of mechanical or electrical damage:
- Upfitter relay(s)
- Upfitter (auxiliary) switches
- Wiring, terminals or connectors

Verify BJB upfitter relay fuses:

Component	Fuse	Rating
AUX 1	F12	15A
AUX 2	F55	15A
AUX 3	F88	10A
AUX 4	F80	10A
AUX 5	F19	5A
AUX 6	F62	5A

Verify BCM fuse 35 (5A).
If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step
If the cause is not visually evident, verify the symptom and refer to the Symptom Chart below.