Yes—the Encore’s “fan always on” complaint usually traces to a stuck relay, control module logic, or the HVAC afterblow feature.
If the radiator fan under the hood or the cabin blower keeps running on your subcompact Buick crossover, you can track the problem fast. This guide shows how to tell which fan is running, what causes the behavior, and the exact checks to stop the drain on your 12-volt battery.
Quick Checks Before You Grab Tools
Start with basic observations. Note when the noise starts, where it comes from, and how long it runs. That single minute of listening can cut diagnostic time by half.
Symptom-To-Fix Map
| Symptom | Likely Cause | What To Check |
|---|---|---|
| Loud whir at front of engine bay, runs with hood open | Radiator fan commanded on, stuck relay, shorted control, high temp reading | Coolant temp on dash scan, fan relays/fuses, debris on condenser, coolant level |
| Soft whoosh inside cabin, starts ~10 minutes after shutdown | HVAC “afterblow” feature drying the evaporator | Listen under dash, HVAC settings, infotainment off, scan-tool setting at dealer |
| Blower stays on low speed with key out | Failed blower control module (transistor), stuck blower relay | Blower module behind glove box, cabin fuses, tap-test relay |
| Fan runs until battery dies | Stuck cooling fan relay, shorted wiring, failed temp sensor reporting hot | Pull cooling-fan fuse to stop the draw, then test relays and sensor |
| Fan cycles for 3–10 minutes after a hot soak | Normal heat-soak management on turbo engine or A/C head pressure | Duration and frequency; if it shuts off on its own, behavior can be normal |
Cooling Fan Vs. Cabin Blower: Tell Them Apart
The radiator fan lives behind the grille and sounds like a high-flow leaf blower. The cabin blower sits behind the glove box and sounds like air passing through vents. If the noise is outside at the front bumper, think radiator. If it’s inside and follows the vent speed, think HVAC.
Why The Encore Cooling Fan Stays On (And What To Do)
1) Stuck Cooling-Fan Relay
Encore models use multiple fan relays to stage speeds. Contacts can weld from heat and age. When stuck closed, the fan runs even with the key out.
How To Check
- Pop the under-hood fuse block cover. Identify the cooling-fan J-case fuses and relays for your year.
- With engine off, pull the fan fuse. If the noise stops, you’ve isolated the circuit. Swap the suspect relay with a same-part relay to confirm.
2) Errant Coolant-Temperature Signal
If the engine control module “sees” an overheat, it will command the fan. A bad sensor or poor ground can report a hot value when the engine is cold.
How To Check
- Use a basic OBD-II reader that shows live coolant temperature. Cold start should read near ambient. A fixed 284°F/140°C or a jumping value points to wiring or sensor trouble.
- Scan for codes like P0116–P0119.
3) A/C Head Pressure After A Hot Stop
On a hot day, head pressure rises with heat-soak. The control logic may run the fan briefly to protect the system. Short cycles that shut down on their own can be normal.
4) Debris On The Condenser Or Low Coolant
Leaves and road grit pack the condenser and radiator fins, reducing airflow. Low coolant exposes the sensor and skews readings. Both conditions can keep the fan running longer than it should.
How To Check
- Shine a light through the grille. If light doesn’t pass through the fins, clean from the back side with low-pressure water.
- When the engine is cold, confirm the surge tank is at the “cold” mark. Top up with the correct Dex-Cool mix if low.
Why The Cabin Blower Keeps Running
1) Afterblow Feature Is Enabled
GM offers an HVAC “afterblow” setting on many models. About 10 minutes after shutdown, the system runs the cabin blower at a low duty cycle to dry the evaporator and cut odors. It runs for a short period, then stops on its own. A dealer can enable or disable the feature with a scan tool.
2) Failed Blower Control Module (Final Stage)
Variable-speed systems use a transistor module. When it shorts, the blower can run with the key out.
How To Check
- Locate the module near the blower behind the glove box. Look for melted connectors or signs of heat.
- Unplug the module. If the fan stops, replace the module and the pigtail if damaged.
Step-By-Step: Pinpoint The Culprit In Minutes
Step 1: Identify Which Fan
Open the hood. If the sound is forward of the engine and strong, you’re dealing with the radiator fan. If the sound is inside and low, it’s the cabin blower.
Step 2: Time The Run
Note start time and stop time. A blower that starts about 10 minutes after shutdown and ends in 10 minutes matches afterblow. A radiator fan that runs endlessly points to a relay or sensor fault.
Step 3: Pull The Right Fuse To Save The Battery
Until you repair the cause, pull the cooling-fan fuse (under hood) or the blower fuse (cabin panel) to stop the drain. This preserves the battery while you diagnose.
Step 4: Test Relays And Modules
Swap the cooling-fan relay with a same-part relay in the box. If the behavior changes, replace the relay. For the cabin blower, unplug the control module; if the blower stops, replace the module.
Step 5: Scan Temperatures And Codes
Use live data to compare coolant temp to ambient on a cold start. Any outlier points straight at a sensor, wiring, or ground issue.
Fuse And Relay Pointers By Model Year
Layouts vary a bit across the 2013–2022 run and the refreshed GX. The under-hood block carries the high-current fan fuses and speed relays; the cabin panel carries the blower feed and HVAC controls. Label names such as “Cooling Fan Low/Mid,” “Cooling Fan High,” or “Linear Power Module Blower” are common. Always match your exact year trim when checking assignments.
For factory layouts, use the official Buick manuals and guides. You can also reference NHTSA-hosted GM service bulletins that mention blower logic and programming steps, such as this afterblow bulletin used on multiple GM vehicles.
Callouts That Help During Checks
- Under-hood block: large J-case fuses for fan power and mini relays for speed control.
- Cabin block: blower fuse and HVAC controller feed.
- Add-on micro-relay bracket on some years near the main block for extra fan stages.
Reference Table: Where Owners Usually Find The Right Circuit
| Year Range | Under-Hood Labels You’ll See | Cabin Panel Clues |
|---|---|---|
| 2013–2016 | “Cooling Fan Low/Mid,” “Cooling Fan High,” “Fan Motor” J-case | Blower fuse and HVAC feed behind lower dash |
| 2017–2022 | Mini relays marked “Cooling Fan – Low/Mid/High,” J-case for fan power | “Linear Power Module Blower” style fuse naming |
| Encore GX | Similar scheme; confirm with VIN-matched manual | Controller fuse behind glove box area |
Normal Behavior Vs. A Real Fault
Short, timed run after shutdown on a hot day can be normal. Endless run that does not stop on its own is not. Cabin blower that starts 10 minutes after parking and ends by itself is likely afterblow. Cabin blower that never quits needs a control module or relay.
Fixes You Can Do At Home
Clean The Front Stack
With the engine cool, remove leaves and grit between the A/C condenser and radiator. Flush from the engine side out with low pressure water. Better airflow reduces fan run time.
Reset By Power-Cycling The Module
Pull the cooling-fan fuse for 30 seconds, reseat it, and retest. Some intermittent logic faults clear with a power reset.
Replace A Failed Relay
Relays are inexpensive and easy to swap. If the suspect relay feels hot or rattles when shaken, replace it.
Swap A Faulty Blower Control Module
Remove the glove box, unplug the module, and fit a quality replacement. Check the harness; replace any burnt pigtail.
Check Coolant And Sensor Health
Top up with Dex-Cool mix if low. If live data looks wrong, replace the coolant temperature sensor and inspect grounds near the thermostat housing.
When To See A Pro
If the fan still runs after relay and module checks, you may have a wiring short, corroded grounds, or a rare engine control module fault. A technician can run voltage-drop tests, command the fan with a scan tool, and verify the HVAC configuration, including afterblow settings.
Cost And Time Estimates
- Cooling-fan relay: 10–20 minutes, low parts cost.
- Blower control module: 30–60 minutes, mid parts cost.
- Coolant temp sensor: 30–45 minutes plus coolant top-off.
- Shop diagnostic scan: usually under an hour of labor.
Battery Saver Tip
If you can’t fix it today, pull the specific fuse when parked or keep a small lithium jump pack in the cargo bin. That avoids a morning no-start while you wait on parts.
Proof-Based Notes
Encore cooling fans use staged relays and resistors to achieve multiple speeds. The cabin blower on many GM models supports an afterblow cycle to dry the evaporator. Official manuals list fuse and relay positions by year, and NHTSA-hosted service bulletins document programming steps that reference blower logic. Use those sources to match your VIN so you work on the right circuit the first time.
Final Checklist: Stop That Endless Fan
- Figure out which fan is running (radiator vs. cabin).
- Time the run to spot normal afterblow vs. a fault.
- Pull the right fuse to stop battery drain while testing.
- Swap the cooling-fan relay; inspect the blower module.
- Scan coolant temperature and check for codes.
- Clean the condenser/radiator stack and restore coolant level.
- Verify settings and fuse labels with your exact manual.