Hi. New on this particular forum. My 08 F150 crewcab 4x4 5.4's heater motor quit on me the other day. This has been an issue since new. If I hit a bump or go over train tracks ect.. it will come back on until I shut the truck off. Motor sounds like its labouring at first, then runs full tilt after that. Just replaced the blending actuator. Fuse 116 in the panel is good, but I've yet to check if theres power to it. I'll go do that now and repost in a minute. Anyone had this issue? I searched the forum and came up with a few similar situations but none exactly like mine. Thanks for any advice.

Regards
Matt

OK, just checked and there is 10.6 v at the 116 fuse location with the key on.

 

Well, heres an update. I started at the heater motor and found out that there was voltage going to it. So, must be the motor. I pulled the motor out and removed the fan. Bench tested it and no go. So I blew the motor out with compressed air, gave the top bushing a shot of silicone lube, and tested it on my Falcon's battery with the car running and voltage output at around 14. Presto. It lit up and ran great. Tested it in the truck and all's good. I dont really trust this repair and will buy a new motor assy on Monday, but goes to show you that some unservicable parts can be manipulated.

matt