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VMAC - Vehicle Mounted Air Compressors
VMAC Technical Support: 888-241-2289
VMAC Knowledge Base: www.kb.vmacair.com
48
Relocating the Battery
VMAC’s universal battery relocation bracket is designed to
accommodate a multitude of frame variations.
Final battery location, and whether to use the supplied relocation
bracket, is up to the upfitter or end user.
Battery Wire Sizing Guide
Combined length of power and ground wires
Recommended wire gauge
Less than 12 ft (3.7 m)
1/0 AWG
Between 12 ft (3.7 m) and 16 ft (4.9 m)
2/0 AWG
Between 16 ft (4.9 m) and 20 ft (6 m)
3/0 AWG
Between 20 ft (6 m) to 24 ft (7.3 m)
4/0 AWG
For cable runs beyond 24 ft (7.3 m), double up the cables.
If relocating the battery to a different location (such as the service
body), refer to the wire size table below (Table 2).
The wire gauges VMAC recommends are designed to provide an
equivalent resistance to that provided by the firewall mounting kit,
which has been extensively tested by VMAC.
If using the frame as the ground return path, ensure the ground
location is clean and protected from corrosion, and the ground
points in the engine bay are also tied in to chassis ground in a
similar manner.
Table 2 — Battery wire size guide
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Remove the OEM ground wire cap nut from the firewall and set it aside (leave
the OEM ground wire in place) (Figure 68).
Figure 68 — Mount battery disconnect bracket
Remove ground
cap nut
OEM ground
strap not shown