How to Replace the Starter Motor on a 2020 Chevrolet Blazer (Step-by-Step Guide)
Tools, parts list, safety prep, and installation steps with OEM torque-spec guidance for 2019
How to Replace the Starter Motor on a 2020 Chevrolet Blazer (Step-by-Step Guide)
Tools, parts list, safety prep, and installation steps with OEM torque-spec guidance for 2019
🔧 Blazer - Starter Motor Replacement
The starter motor is the electric motor that spins the engine so it can start. On your Blazer, the starter is mounted to the engine/transmission bellhousing area and is usually accessed from underneath after removing underbody shields.
Difficulty Level: Intermediate | Estimated Time: 2-4 hours
⚠️ Safety & Precautions
- 🛑 Disconnect the negative battery cable before touching the starter wiring (the starter cable is always “hot” and can short to ground).
- 🔥 Let the exhaust cool completely before working underneath.
- 🧱 Support the Blazer with jack stands on solid, level ground; never rely on a floor jack alone.
- 🧤 Wear safety glasses and gloves; road debris will fall when shields come off.
- 🔌 Battery disconnect is required for this job.
🔧 Required Tools
You'll need the following tools for this repair:
- Safety glasses
- Mechanic gloves
- Wheel chocks
- Floor jack (rated 3-ton minimum)
- Jack stands (rated 3-ton minimum)
- 10mm socket
- 13mm socket
- 15mm socket
- 3/8" ratchet
- 3/8" torque wrench
- 6" socket extension
- 12" socket extension
- Universal joint socket adapter
- Trim clip removal tool
- Flat-blade screwdriver
- Fender cover
- Work light
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Starter motor - Qty: 1
- Starter electrical terminal nut kit - Qty: 1
- Dielectric grease - Qty: 1
📋 Before You Begin
- Park on level ground, shift to Park, and set the parking brake.
- Open the hood and install a fender cover to protect paint.
- Record radio presets if you care about them (battery will be disconnected).
- Plan access: most Blazer starter replacements are easiest from underneath after removing the lower engine splash shield.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Disconnect the battery
- Use a 10mm socket to loosen the negative battery terminal clamp.
- Remove the negative cable and position it so it cannot spring back onto the battery post.
- Tip: Wrap the terminal with a glove.
Step 2: Raise and support the Blazer
- Place wheel chocks behind the rear wheels.
- Lift the front with a floor jack at the proper front jacking point.
- Set the Blazer onto jack stands and gently shake the vehicle to confirm stability.
Step 3: Remove the lower splash shield(s)
- Use a trim clip removal tool and flat-blade screwdriver to remove push pins/clips.
- Use a 10mm socket (common) to remove any shield bolts.
- Lower the shields and set them aside in order.
Step 4: Locate the starter and verify wiring
- Use a work light to find the starter at the engine/transmission mating area (bellhousing).
- You’ll see a large battery cable on the starter main terminal and a smaller control connector.
- Tip: Take a photo before disconnecting.
Step 5: Disconnect starter electrical connections
- Remove the starter solenoid terminal cover (if equipped) using a flat-blade screwdriver.
- Disconnect the small control connector by releasing its lock tab (use a flat-blade screwdriver carefully if needed).
- Remove the main battery cable nut using a 13mm socket (common size) and pull the cable off the stud.
- Apply a light smear of dielectric grease to the connector seal (not the stud threads).
Step 6: Remove the starter mounting bolts
- Support the starter with one hand.
- Use a 15mm socket, 3/8" ratchet, extensions, and a universal joint socket adapter as needed to remove the starter mounting bolts.
- Carefully lower and remove the starter from the bellhousing.
Step 7: Install the new starter
- Position the new starter and start both mounting bolts by hand to avoid cross-threading.
- Tighten the mounting bolts with a 3/8" ratchet, then final-tighten using a 3/8" torque wrench to Torque to OEM specification.
- Tip: Hand-start bolts at least 4 turns.
Step 8: Reconnect the starter wiring
- Install the main battery cable onto the starter stud.
- Install a new terminal nut (from the kit) and tighten with a 13mm socket, then final-tighten with a torque wrench to Torque to OEM specification.
- Reconnect the small control connector until it clicks/locks.
- Reinstall the terminal cover (if equipped).
Step 9: Reinstall splash shield(s)
- Reposition shields and install bolts with a 10mm socket.
- Reinstall push pins/clips using a trim clip removal tool.
Step 10: Lower the Blazer and reconnect the battery
- Raise slightly with the floor jack, remove jack stands, then lower to the ground.
- Reconnect the negative battery cable and tighten using a 10mm socket.
✅ After Repair
- Start the engine and confirm it cranks strongly with no clicking/grinding.
- With the engine running, check that no warning lights appear related to low voltage.
- Recheck under the vehicle for any loose shields or hanging wiring.
- If it still cranks slow, have the battery and charging system load-tested.
💰 DIY vs Shop Cost
Shop Cost: $550-$1,050 (parts + labor)
DIY Cost: $180-$450 (parts only)
You Save: $370-$600 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2-4 hours.
🎯 Ready to get started?
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