Replaced heater core ,thermostat and rad still have no heat
any suggestions . Thanks for the great information on removing
the heater core. It worked great.

 

If it's a F-250 try the SD/ heavy duty section, or modular 4.6/5.4 section.

 

No, he's in the right forum. He has a F-250 LD with a 5.4 engine.

When you have driven your truck for a bit go out and touch your heater core hoses. Are they both HOT? They should be. If they are then go into the cab and pull the **** off the middle control for your heater (the temperature). Look at the back...is there a small crack on it? If so, switch with the one for fan speed and see if that helps.

Also could be a blend door problem. Do a search for that in this forum.

If your heater core hoses aren't hot then you have a different problem...water pump?

-Matt

 

maybe i titled this wrong. it's really just a temporary patch but its quick and works. i have a 97 250LD 5.4 with the all to common broke blend door arm. i went far enough to find i actually do have a broke blend door. on this day i could not spend all day removing the d$#% entire dash assy.to be able to remove the d$#% heater plenum to get to the d$%# broke blend door. pita
being desperate for heat since i waited til it's colder than crap, i carefully examined the visible portion of my heater plenum while lying in the floorboard cursing ford. i then took my drill and drilled a 1/4" hole through the plenum at approx. 1/2" from the corner which is the outer edge of the blend door seat. i then insert a piece of wire bent like fish hook on end through 1/4" hole and hook it over end of flopping blend door. pull blend door shut and bend wire at hole to hold it shut. maybe not a pro fix but aaaaaaaaaaaaaaah it's good to have a heater and it's a 15 min. job

 

the blend door and operator are above the trans hump-- read this

https://www.ford-trucks.com/forums/6...ght=blend+door

 

Ok so only warm at idle cold under way was my problem first replaced heater core was leaky fogging Windows removed whole fn dash fun job lol yeah. Still no heat next radiator cracked replaced radiator still no heat ok so thermostat 195% temp still no heat tried the old piece card board on half radiator nope still no heat check blend door and controls they are all working properly still only warm at idle cold under way. Was getting a water pump and explained my issue with auto parts worker he says its your resistor. Ok what's that lol under the air box on passenger side near transmission hump and fire wall there's a plug mine said ad something on it with blue print in plug that wire and take that resistor out mine was 2 screws took less than 5 mins to swap out guess what now there's heat lol Ben a drug out process for me I hope this save you guys some time and money let me know if this helps your truck thanks and have a happy new years fellas n gals be safe

 

Sorry forgot to post part # on resistor ru1076