XS Power XSP320-311- VCM/GM “SI” Power Module
Many in-stock orders ship within 1-2 business days, but timing varies by item. Custom, built-to-order, oversized, special-order and supplier-direct products may need extra processing time. Free shipping applies to qualifying orders over $99 in the contiguous US. Approved returns may be subject to a restocking fee.
Most products are covered by the manufacturer's warranty against defects. Damage from over-powering or improper installation isn't covered — we'll help coordinate any valid claim.
Tell us your vehicle, subwoofers and electrical setup and our team will help you match the right gear. Reach out before you buy.
Factory GM vehicles with active voltage management systems require a specialized interface, and the XS Power XSP320-311 VCM/GM SI is purpose-built for exactly that application. This voltage control module communicates properly with GM Smart Idle technology, allowing you to add secondary battery capacity without triggering charging system warnings or throttling amplifier voltage to 16V rail demands.
GM-Specific Isolation Without Compromise
Standard battery isolator modules can clash with GM ECM charging strategies, but the XSP320-311 VCM/GM SI is engineered to play nice with those factory systems. It functions as a true dual battery isolator and car audio power module in one unit, giving GM owners the ability to run auxiliary audio batteries without fighting the vehicle computer. A must-have for any GM-platform build where secondary battery power is on the plan.
Specifications
| Type | Dash-Mounted Voltage Controller |
| Display | Blue LED Readout |
| Alternator Compatibility | Made for GM “SI” Alternators - 1969 to 1988 |
| Wiring Harness | Custom Wiring Harness Included |
| System Voltage | Works With 12, 14, or 16-Volt Systems |
| Alternator Type | Compatible With Stock & Aftermarket Alternators |
Authorized XS Power dealer at JS Ultimate Sounds. Free shipping on orders $99+.
PROP 65 WARNING: This product can expose you to chemicals including lead and lead compounds, which are known to the State of California to cause cancer or birth defects or other reproductive harm. Wash hands after handling.
For more information, visit www.P65Warnings.ca.gov
