Chevy Express Van Electrical System Build Guide

· 2 min readElectrical System
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The Chevy Express (G-Van) is a popular conversion platform — it's affordable used, mechanically well-understood, and has a large cargo area. Here's how to wire a house electrical system into one.

What makes the Express different

Engine: Most 2003–present Express vans run a 4.3L V6 or 6.0L V8 Vortec. Both use conventional (non-smart) alternators, typically putting out 105–145A. This is good news — you don't need a DC-DC charger for smart alternator compatibility, though a DC-DC charger is still the right choice for LiFePO4 to regulate charging properly.

Chassis ground: The Express body is steel throughout. Chassis grounding is straightforward — find a clean, unpainted bolt or drill a new chassis ground point.

Wire routing: Route wiring along the driver's side rocker panel under carpet or use the existing wire channels. Solar wiring from the roof comes down the B-pillar or through a grommet in the roof.

Roof: The Express has a raised roof option (Quigley 4WD and others) or a standard roof. Standard roof has limited area for solar panels — typically 200–400W. A Sportsmobile-style fiberglass high roof pop-top allows significantly more panels.

Weekend build:

  • 100Ah LiFePO4 (single Group 31-sized battery fits cleanly)
  • 200W solar + 20A MPPT controller
  • 20A DC-DC charger (Renogy DCC20S)
  • 1,000W inverter (optional)
  • Victron SmartShunt + display

Full-time build:

  • 200Ah LiFePO4 (two 100Ah batteries in parallel)
  • 300–400W solar
  • 30A DC-DC charger
  • 2,000W inverter
  • Fuse block for 12V accessories

Wiring the DC-DC charger

The DC-DC charger connects between the starter battery (engine bay) and the house battery (cargo area). Run 10 AWG wire (for a 20–30A charger) from the starter battery positive terminal through a firewall grommet into the cargo area, to the charger, then to the house battery.

Run a separate wire from the DC-DC charger's ignition input to a switched 12V source (fuse box) so it activates when the ignition is on.

Solar installation

The standard Express roof is metal — easy to attach panel mounts. Options:

  • Z-brackets: Bolt through the roof with sealant (Dicor or self-leveling lap sealant)
  • Aluminum extrusion rails: Cleaner look, allows panel adjustment
  • Run solar cable through an AM2 cable entry gland on the roof
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