auxiliary battery CHEVROLET ASTRO 2004 Owners Manual

Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission ¯uid (don't over®ll),
engine oil, axle lubricant, belt, cooling system and
brake system. Each of these is covered in this manual,
and the Index will help you ®nd them quickly. If
you're trailering, it's a good idea to review these sections
before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
If you have the optional trailering package, your vehicle
will have an eight-wire harness, including the center
high-mounted stoplamp battery feed wire. The harness
is stored on the passenger's side of the vehicle near
the rear wheel well. This harness has a 30 amp battery
feed wire and no connector, and should be wired by
a quali®ed electrical technician. After choosing an
aftermarket trailer mating connector pair, have the
technician attach one connector to the eight-wire trailer
harness and the other connector to the wiring harness
on the trailer. Be sure the wiring harness on the trailer is
taped or strapped to the trailer's frame rail and leave
it loose enough so the wiring doesn't bend or break, but
not so loose that it drags on the ground. The eight-wireharness must be routed out of your vehicle between the
rear door and the ¯oor, with enough of the harness
left on both sides so that the trailer or the body won't pull
it. If you do not have the optional trailering package,
your vehicle will still have a trailering harness. The
harness is located near the passenger's side rear wheel
well. It consists of six wires that may be used by
after-market trailer hitch installers.
The technician can use the following color code chart
when connecting the wiring harness to your trailer.
·Brown: Rear lamps.
·Yellow: Left stoplamp and turn signal.
·Dark Green: Right stoplamp and turn signal.
·White (Heavy Gage): Ground.
·Light Green: Back-up lamps.
·White (Light Gage): Center High-Mounted Stoplamp.
·Blue: Auxiliary circuit (eight-wire harness only).
·Orange: Fused auxiliary (eight-wire harness only).
Store the harness in its original place. Wrap the
harness together and tie it neatly so it won't
be damaged.
4-44

Fuse/Circuit
BreakerUsage
A/C COMPAir Conditioning Enable Relay and
Compressor
RR HTR/AC Rear Heater and Air Conditioning
ATC Active Transfer Case-L Van
FRT HVAC Front Heater and Air Conditioning
ENG-IOxygen Sensors, Camshaft Position
Sensor, Mass Air Flow Sensor,
Evaporative Emission Canister Vent
Solenoid
IGN-E Air Conditioning Enable Relay Coil
ECM-IFuel Injectors 1±6, Crankshaft
Position Sensot, VCM, Coil Driver
Module (EST), Ignition Coil
Blank Not Used
RH HDLMP Right Headlamp
LH Headlamp Left Headlamp
Blank Not Used
Blank Not UsedFuse/Circuit
BreakerUsage
DIODE-1 Air Conditioning
Blank Not Used
Blank Not Used
Blank Not Used
LIGHTINGCourtesy Fuse, Power Adjust
Mirrors Fuse, Truck Body Control
Battery Fuse
BATTPower Accessory Circuit Breaker,
Stop/Hazard Fuse, Auxiliary Power
Fuse, Cigarette Lighter Fuse, Radio
Battery Fuse
IGN A Starter Relay, Ignition Switch
IGN B Ignition Switch
ABSElectronic Brake
Control Module
Blank Not Used
RAP Radio Accessory, Power Windows
HTD MIR/RR
DEFOGRear Window Defogger,Climate
Control Head
5-101