Hello,
I'll try to keep it short, my nephew bought a 2013 Mustang v6 3.7l automatic with 85k miles. Couple days later the vehicle overheated, we replaced the t-stat and water pump took it for a test drive and everything seemed fine, no leaks, temp gauge was normal so we assumed problem solved. Next day, driving around with AC on the temp gauge spiked to red so he pulled over and turned it off. Parked with AC on the high speed fan starts but i'm not 100% sure it's not shutting off at some point, what i can't figure out is the low speed fan, we ran the vehicle for 30min on a 90deg day and the low fan never came on. The fuse looks good and we verified the relays by swapping them out with the windshield wiper relay, i removed the fuse box looking for burnt or bad connections, nothing. I removed the fan connector and verified 12v on high speed but nothing for low speed. I don't have a handheld programmer or software to force the low fan to come on. My nephew is pretty upset that he can't drive the mustang so any help would be appreciated.

One a different note but related, we found a service invoice from FORD where the previous owner reported overheating, they replaced the fan and called it good. Does anyone know if a service repair warranty is transferrable to new owners?

Thanks,
Rob

 

Is the fan actually coming on

 

Yes, but only when the AC is on.

 

Try calling the shop that did the repair. I doubt if the service warranty is transferrable for a 2013, unless it was specified in the service contract. However, they may be able to assist you in diagnosing the problem. Are you getting any codes or check engine light when it overheats?

 

My 2013 had this same issue and it wasn't the fan but the relay that failed.

 

royjj12 - Call the repair shop for assistance, good idea. No codes or check engine light.

JimC - You mentioned the relay, I verified that both fuse box relays are good, are you referring to another relay?

Others mentioned a dropping resistor that controls the low fan and the temp sensor, any idea the location and how to test it?

Thanks,
​​​​​​​Rob

 

Update on the overheating issue.

We removed the fan pigtail and discovered that either the previous owner or the car lot where he bought the vehicle tried to replace a bad wire, probably the worst solder job I've ever seen. We bought a new pigtail and the young man is back on the road.

Thank you for all the replies.