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Electrical
Requirements
Power Harness
The OEM is responsible for the design of the Main Power Harness.
Note:
Main power and ground must be able to carry 20 amps @ 9 volts with no more than .05 ohms.
To calculate the .05 ohms, take the length of the wire from the battery or starter to transmission and multiply the ohms
per foot for that wire gauge.
12AWG (3.0mm²)= .0016 ohms per ft. (25.4mm)
10 AWG (5.omm²)= .001 ohms per ft. (25.4mm)
Each connection is < .005 ohms
Example: The Main Power Harness is four foot long made of 12 AWG. (3.0mm²) which equals .0016 ohms per foot. +12
vdc and ground wires combined equals 8 feet (203mm).
The Main Power connector is connected to the starter, which equals six connections. According to the Delphi Packard
Electrical Systems. each connector is .005 ohms.
1.
8ft * .0016 ohms = .013 ohms
2.
6 connectors * .005 ohms = .03 ohms
3.
.03 + .013 = .043 ohms
For this example the total resistance is a .043 ohm.
Note:
Main Battery source can be starter or battery terminal. Frame rails and splices into other harnesses are not con-
sidered reliable battery sources.
30 AMP fuse
Battery power
(Non-switched power)
run to starter or Battery
Transmission Controller (ECU)
