A Step-by-Step Guide to Installing Your High Output Alternator for Maximum Efficiency
Last updated: May 2026
This is a step-by-step installation guide for your JS Alternators high output alternator. For the most complete version with tools list, wiring details, and verification steps, see: How to Install a High Output Alternator: Complete Guide
Before You Begin
Required before installation:
- Big 3 wiring upgrade kit: Complete Guide
- Correct shorter belt (spec included with your order)
- ANL fuse holder and fuse for B+ wire: Fuse Sizing Guide
- Socket set, serpentine belt tool, multimeter
Installation Steps
- Disconnect negative battery terminal. Wait 5 minutes.
- Photograph belt routing, then use belt tool on tensioner to release and remove belt.
- Disconnect alternator wiring harness plug and B+ terminal cable.
- Remove all alternator mounting bolts (2-3 bolts typically). Remove alternator.
- Install JS Alternators high output unit. Thread bolts by hand first, then torque to spec.
- Reconnect wiring harness plug (should click) and B+ cable. Tighten B+ nut firmly.
- Install new shorter serpentine belt per routing diagram. Verify all pulleys seated.
- Complete Big 3 wiring upgrade now if not already done.
- Reconnect battery negative terminal. Start vehicle.
- Verify charging voltage: 13.5-14.8V at battery with multimeter. Turn on accessories and verify voltage stays above 13.0V.