96 Bronco XLT , heater does not work??

[SVTGhoust]

OK guys,

I have been trolling around the boards trying to troubleshoot and solve this issue. But I have had no luck. I just picked up a 96 bronco 5.8 XLT. The truck has 127000 miles on it. The heater does not blow hot. It blows cold and the A/C works just fine.

So far here is what I have done:

1. Replaced the thermostat
2. flushed the coolant
3. replaced the heater core

But still no heat. I am freezing my ass off while driving at night time and in the early morning. What else could it be? Any other suggestions guys?

[Daves 88']

Mine is a resistor type system, but I think later on they used vaccum for the actuator apparatus deal, whatchamacallit. I understand it's some apparatus on your blower motor on the firewall I wreckon. Somebody who has a later model will chime in sooner or later to get it straight.
Got any coolant leaks coming from the passenger side floorboard?

[liltimmy08]

Could be air in the system or not enough coolant. It could also be your heat exchanger knob... or whatever the fawk its called that switches you from cold to hot.

[SVTGhoust]

no coolant leak that I can see. I have replaced the heater core and checked to ensure that all hoses are tight

[ronco93]

Originally Posted by liltimmy08

Could be air in the system or not enough coolant. It could also be your heat exchanger knob... or whatever the fawk its called that switches you from cold to hot.

Check the vacuum line that goes into the black heater core/AC evaporator coil housing on the passenger side of the firewall. That's what drives the flap that mixes your hot and cold air. If that doesn't work, you're probably going to end up pulling apart that housing.

[pattapit]

I understand that you changed the heater core...

that being said, mine was blowing cold when I got it, I took off the two hoses going into the passenger side where the heater core is... I put a hose on it and flushed it tough.

Maybe your pipes from where the hoses connect to the heater core are plugged? I donno, just a suggestion. and it's very easy to try, so why not?!

[ronco93]

Try these two things:

1)With engine at operating temp, are the heater core hoses hot to the touch? If no, then you have an issue with the cooling system.

2)With the A/C running, if you adjust the cold/hot control, does the temp of the air comming out of the vents change? If no, it sounds like its your flap that adjusts the air temp

[cemusic86]

check that you have enough coolant in the system.....sounds crazy but trust me..it works..;-)

[SVTGhoust]

[quote=ronco93;2006789]Try these two things:

1)With engine at operating temp, are the heater core hoses hot to the touch? If no, then you have an issue with the cooling system.
QUOTE]

Check this and the 2 hoses going to the core are cold at operating temperature compared to the upper radiator hose. should I try flushing the 2 hoses? The truck has good coolant (just changed the radiator hoses and coolant)

Any further suggestions?

[ronco93]

Originally Posted by cemusic86

check that you have enough coolant in the system.....sounds crazy but trust me..it works..;-)

Did you remember to top off the radiator w/ engine running at operating temp after the t-stat opened?

Or when you flushed perhaps you dislodged some gunk and it didn't make it all the way out, causing a blockage somewhere?

[DblA]

I've had this problem - I just needed to run it with the radiator cap off until all the air bubbled out. Mine had a lot of air in the system and it had gotten trapped in the heater core, but after it works great. Don't know if this is the case with yours but could be.

[poptop]

Originally Posted by DblA

I've had this problem - I just needed to run it with the radiator cap off until all the air bubbled out. Mine had a lot of air in the system and it had gotten trapped in the heater core, but after it works great. Don't know if this is the case with yours but could be.

this goes back to cheking if both hoses are hot when at operating temp if not then this could be the problem also if both hoses are not getting hot try flushing the new heater core

[USMCGunrock0811]

Originally Posted by DblA

I've had this problem - I just needed to run it with the radiator cap off until all the air bubbled out. Mine had a lot of air in the system and it had gotten trapped in the heater core, but after it works great. Don't know if this is the case with yours but could be.

x2...it has happened to me

[SVTGhoust]

Originally Posted by DblA

I've had this problem - I just needed to run it with the radiator cap off until all the air bubbled out. Mine had a lot of air in the system and it had gotten trapped in the heater core, but after it works great. Don't know if this is the case with yours but could be.

This did the trick. thanks for all the help guys.