Q: Radiator fan running max frequently

asked by on May 02, 2017

When i start my truck, sometimes my radiator fan comes on full blast immediately. After about thirty seconds it'll go to normal speed. Also while driving it will come on full blast periodically. The truck isn't running hot and it even does it during cold temperatures on my first start for the day. I was thinking maybe my water pump and thermostat need changing, but i have/never have a check engine light or any other warning on the dashboard.

My car has 95000 miles.
My car has an automatic transmission.

Electrical components are not working Inspection $79.99 - $89.99 Get a Quote

The fan circuit has a relay, switch contacts, and a temperature sensor. There may be other circuit components as well. If the fan is coming on when it is not supposed to, there is a fault in one or more of those components or perhaps an intermittent short to ground in the circuit. Basically, if you want to resolve it yourself, using the wiring diagram (from the Factory Service Manual, FSM) you can methodically trace the circuit until the fault(s) is found. If you want these steps performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request an electrical component diagnostic - uncommanded fan operation and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

What others are asking

How do I clean the rearview mirror?

A dirty rearview mirror is not only a nuisance to drivers, but a potential hazard. Do not spray any chemicals or glass cleaner directly onto the mirror. Instead, spray a gentle glass or household cleaner onto a soft, clean, damp...

2012 VW Beetle Turbo. Vehicle will not start.

Prior to performing diagnostics be sure you have a fully charged battery that passes a load test. Then, confirm that the engine immobilizer system (security system) is not activated thus preventing the car from starting. Basically, if a fully charged...

Heater is blowing mixed temperature air into the cabin area.

Hi there. Check the blend doors to the heater system. The doors could have a leak with the weather stripping. Then check the air ducting in the dash up by the heater blower motor and see if there is a...

Honda Civic with screaming timing belt when cold and wet

You probably need a fan belt. Timing belt is inside the timing cover and it has cogs on it and it can't squeal because it's got cogs and it can't slip. If it groans, it means that the timing...

How do I disengage the parking brake?

Before driving, you should always disengage the parking brake. If you attempt to drive with the parking brake on, you can do serious damage to your brake system. To disengage the parking brake, press the Release button at the end...

Idrive and TPI malfunction.

Hello. From what you describe it would appear that your vehicle is experiencing some sort of electrical issues. If the Idrive system is not working properly then it may be possible that the Idrive computer has failed, or possibly the...

How do I use the air conditioning?

The air conditioning system brings cold air into your vehicle, to help keep you cool on hot days. To turn on the air conditioning, press the A/C button in the middle of the Fan Speed Control knob. A light will...

I have a 2004 gmc yukon , when i turn on right turning signal the high beam comes on?

Generally this is something caused by the flasher relay going bad or potentially, the turn signal switch in the steering column. The flasher relay is a small relay that allows the lights to flash based upon current flow and a...

ABS light, brake light, and engine power loss flashing on screen

Hi there, thanks for writing in. This is a typical and common problem with multiple vehicles that have sensors that monitor systems like ABS. The general issue is that when it gets damp and wet, the sensors absorb the liquid...

Related articles

The Top 5 Selling Cars in Arkansas in 2012
Arkansas, Arkansas, like many other states, has to deal with a wide range of weather, from the stifling to the icy. This means drivers need vehicles that can handle the heat while also helping them get through slippery conditions. In...
Symptoms of a Bad or Failing Electronic Ignition Pickup
If your car has an electronic distributor ignition system and the engine stalls or car does not start, you may have to replace the ignition pickup.
A Buyer's Guide to the 2012 Mercedes-Benz GL-Class
In In the world of full-size SUVs, Mercedes-Benz has made a name for themselves by offering unrivaled luxury in a field where the size of the engine is often the most important metric. While the 2012 Mercedes-Benz GL Class definitely...