Buy Now | Log In | ALLDATA Corporate Site |
Back To Home Page
Log In To Your Subscription
Go To ALLDATA Back Home
Buy A Subscription! Back Home About ALLDATA Information View Sample Vehicles Read Testimonials View Factory Service Bulletins and Recall Titles Contact Us
Dowload Our Navigation Chart
February 2015: New vehicles added including 2014 GM.
• View New Vehicles
October 2014: Release of 2013 along with initial 2014 Vehicles
• View Vehicles
View All News and Updates:
• Go To News
Tech Tips
  Read All Tech Tips

ALLDATA Tech Articles Are Updated Weekly
• View All Tech Articles

  Dodge Durango: Brake Pulsation Problems In Paul's Durango
• Read Dodge Article
Fixing A Smelly Audi Audi Tech Tip: A4 begins to Smell caused by a Faulty Hose Composition
• Read Audi Article
Why Do You Need To Change Your Timing Belt? Why Replace Your Timing Belt
• Read Belt Article
Jim Grant Tech Tips Jim Grant Tech Tips
A collection of helpful articles based on reader submissions
Home >> Featured Tech Articles >> Go Back
  Jim Grant's Tech TipsJim Grant's Tech Tips
Below is a collection of Jim Grant's Tech Tips sorted by Vehicle Make. These Tech Tips were answers to questions submitted to Jim by users over the course of many years.
If you have any questions, please feel free to email us.



Lincoln - Mercury
  Jim Grant's Tech Tips

‘90 Pontiac Sunbird Turbo 2L., Inoperative Cooling Fan
Q: The radiator cooling fan will not come on when the motor heats up on my ‘90 Pontiac Sunbird Turbo with a 2L engine. I replaced the heat sensor, but still had the same trouble. I found the fan relay was not operating, yet the relay will operate if I apply a ground. Any ideas?..... Bob

A: The relay for the cooling fan is controlled by the vehicle’s computer. For the computer to activate the cooling fan it looks for information (inputs) that it interprets as a need to turn the cooling fan on or off. It’s all part of that "if this, then that" programming stuff. The coolant temperature sensor is one input that is often confused with the coolant temperature sender and wrongly replaced. The sender is for the gauge and the sensor is for the computer, big difference. Also the computer will turn the cooling fan on if it sees that the A/C has been turned on. If you were to come into our shop this is how the diagnosis would go. The first thing would be to turn the A/C on to see if the cooling fan comes on. If not then, the cooling fan relay would be identified and then by-passed. If the fan worked then the relay, wiring, computer or computer inputs would be of concern. If the fan did not work, the wiring power supply (fused link) and ground, and fan motor would be checked. A word of caution, when probing the wiring at the relay contacting the wrong wire at the right time "will" let the magic out (ruin the computer) of the vehicle’s computer and add $100 to $200 more dollars to your cooling fan problem.

Have any Questions About Please Email Us
Buy Now | Log In | About | Sample Vehicles | Testimonials | Join Affiliate Program