How to Replace the Alternator on a 2013 Subaru Forester (DIY Guide)
Step-by-step instructions with required tools/parts, belt tensioning tips, and key torque specs for 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
How to Replace the Alternator on a 2013 Subaru Forester (DIY Guide)
Step-by-step instructions with required tools/parts, belt tensioning tips, and key torque specs for 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
🔧 Forester - Alternator Replacement
The alternator charges the battery and powers your Forester’s electrical system while the engine runs. On your Forester, the alternator is belt-driven at the front of the engine, so the job mainly involves loosening the belt, swapping the alternator, then setting belt tension correctly.
Difficulty Level: Intermediate | Estimated Time: 1.5-3.0 hours
⚠️ Safety & Precautions
- ⚠️ Disconnect the battery negative terminal first to prevent a short (the alternator “B+” stud is always hot if the battery is connected).
- ⚠️ Let the engine cool before working near the radiator fans and turbo-area heat.
- ⚠️ Never pry on aluminum parts aggressively; brackets can crack.
- ⚠️ Keep tools away from the alternator electrical studs; accidental contact can melt tools/wiring.
🔧 Required Tools
You'll need the following tools for this repair:
- 10mm socket
- 12mm socket
- 14mm socket
- 10mm combination wrench
- 12mm combination wrench
- 14mm combination wrench
- 3/8" drive ratchet
- 3/8" drive extension set
- Torque wrench (10–80 ft-lb range)
- Flat trim tool
- Needle-nose pliers
- Small pick tool
- Work light
- Nitrile gloves
- Safety glasses
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Alternator - Qty: 1
- Alternator/Power steering drive belt - Qty: 1
- Dielectric grease - Qty: 1
📋 Before You Begin
- 🧰 Park on level ground, shift to Park, and open the hood.
- 🧰 Take a quick photo of the belt routing before removal.
- 🔋 Disconnect the battery: use a 10mm wrench to remove the negative (-) terminal and isolate it so it can’t spring back.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Remove the intake snorkel/ducting (for working room)
- Use a flat trim tool to pop any plastic clips.
- Use a 10mm socket to remove any retaining bolts, then lift the duct out.
Step 2: Loosen the alternator belt tension
- Locate the alternator adjustment hardware at the front of the alternator.
- Use a 12mm socket (or 12mm wrench) to loosen the alternator lock bolt(s) (do not remove them yet).
- Use a 12mm socket to turn the belt adjuster bolt to relieve tension until the belt slips off the alternator pulley.
- If the belt is cracked, replace it.
Step 3: Disconnect alternator electrical connections
- Remove the rubber protective cap from the alternator output stud (the “B+ terminal,” meaning the main battery-positive output).
- Use a 10mm socket to remove the B+ terminal nut, then pull the ring terminal off.
- Unplug the alternator connector by pressing the tab; use a small pick tool gently if it’s stuck.
- When reinstalling the B+ nut later: Torque to 7.5 N·m (66 in-lb).
Step 4: Remove the alternator mounting bolts
- Support the alternator with one hand.
- Use a 14mm socket and ratchet to remove the main pivot/mount bolt(s), then lift the alternator out.
- Keep bolts in order for reassembly.
Step 5: Install the new alternator
- Set the new alternator into the bracket and start the mounting bolts by hand.
- Use a 14mm socket to tighten the alternator mounting/pivot bolt(s): Torque to 45 N·m (33 ft-lb).
- Use a 12mm socket to tighten the adjuster lock bolt(s): Torque to 18 N·m (13 ft-lb).
Step 6: Reconnect alternator wiring
- Plug in the alternator connector until it clicks.
- Install the B+ ring terminal and nut using a 10mm socket, then Torque to 7.5 N·m (66 in-lb).
- Apply a small amount of dielectric grease inside the rubber cap and reinstall the cap over the B+ stud.
Step 7: Reinstall the belt and set belt tension
- Route the belt correctly on the pulleys using your photo as a guide.
- Use a 12mm socket to turn the adjuster bolt to tension the belt.
- After tensioning, use a 12mm socket to tighten the lock bolt(s): Torque to 18 N·m (13 ft-lb).
- Too tight can kill bearings.
Step 8: Reinstall the intake snorkel/ducting
- Reinstall the ducting and clips using a 10mm socket and flat trim tool.
Step 9: Reconnect the battery
- Reconnect the negative (-) terminal using a 10mm wrench and tighten snugly.
✅ After Repair
- 🔍 Start the engine and confirm the belt runs smoothly with no squeal or wobble.
- 🔍 Check that the battery/charging warning light stays off.
- 🔍 If you have a multimeter: measure battery voltage at idle; you typically want about 13.5–14.7V with the engine running.
- 🔍 Recheck belt tension after a short test drive; new belts can stretch slightly.
💰 DIY vs Shop Cost
Shop Cost: ₹18,000-₹35,000 (parts + labor)
DIY Cost: ₹8,000-₹22,000 (parts only)
You Save: ₹10,000-₹13,000 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-3.0 hours.
🎯 Ready to get started?
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