heater problem

[blindside56]

i need help i have a 78 bronco and no heat, new heater core, new thermostat, the flapper door works the selection works..i am lost and people i know seem to be lost where to look what to look for, it blows air just cold no matter the setting, and it blows air outta all the different sections so that all seems to be work what else could it be..please help

 

[Seabronc]

You may just have an air lock in the heater hoses or core. This would be good time to add a flush T in the return hose of your heater. Cut the hose, insert the T (IT HAS A CAP). Run the engine and open the cap until the water starts to come out, then close it. I'm not sure about the 78/79 engines, but on most Fords, the heater loop is pushing water all year around. The flapper door is what keeps the heat out of the cabin in the summer. The flow path is from the water pump, to the heater core and back to the intake side of the thermostat at the top of the intake manifold.

Good luck,

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[blindside56]

yeah it has one of those things in it and i have had water run outta it, but still no heat its super confusing....someon told me the other day it might be cuase its a 190 thero. in it could that be the problem?, but i know theres water running through the lines, cause i didn't have a hose tight enough the other day after messin with it, and had a lil leak so i know water gettin to the heater core...could the problem be though since it has factory a/c but all that was removed person who did it before me took it out, and took something needed out?

 

[Seabronc]

yeah it has one of those things in it and i have had water run outta it, but still no heat its super confusing....someon told me the other day it might be cuase its a 190 thero. in it could that be the problem?, but i know theres water running through the lines, cause i didn't have a hose tight enough the other day after messin with it, and had a lil leak so i know water gettin to the heater core...could the problem be though since it has factory a/c but all that was removed person who did it before me took it out, and took something needed out?

You have to make sure it is a real good flow, and make sure you are checking on the return hose, ( the one that goes to the intake manifold). Take the cap off and see that it is pumping real good. No, I don't think it is due to the 190 T-stat. The water pump circulates the engine block water through the heater even when the T-stat is closed. The path is through the bypass hose to the pump, then to the heater and back to the intake manifold.

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[blindside56]

so lets just say its not a fast flow what would i do to slow the problem?, yeah the hose comes out of the water pump runs to the heater core, then right back next to the thermo housing into the block, it wouldn't matter which side of the heater core the hoses plug into right, just in case they got switched? never thought they would...i am lost still thanks for the help

 

[Seabronc]

It should have a strong flow, if not, then maybe you have pump problems.

Good luck,

>-

 

[blindside56]

yeah i thought i had pump problems but if i had pump problems wouldn't it over heat or run hot or anything....i mean it runs on the low side of normal all the time(according to the gauge) which i know its not that hot cuase i can hold the radiator hose, and touch the radiator its not that hot....so thats why i don't think its a pump problem unless i am wrong?

 

[Seabronc]

yeah i thought i had pump problems but if i had pump problems wouldn't it over heat or run hot or anything....i mean it runs on the low side of normal all the time(according to the gauge) which i know its not that hot cuase i can hold the radiator hose, and touch the radiator its not that hot....so thats why i don't think its a pump problem unless i am wrong?

That's a bit of interesting new information. Something is wrong there. You shouldn't be able to touch that thing when hot. WE are back the the T-stat I pho phoed earlier. At a 190 degrees, it should be pretty uncomfortable to touch them. Are you sure that there is a T-stat in there? Or perhaps one that is stuck open all the time.

>-

 

[blindside56]

theres a t-stat in there i put it in there, after i took one out, and after i put the new on in it actually started showin up on the guage a temp.. the hose isn't super hot, i mean its hot enough i think but not to hot, i donno its weird i tell ya but runs and drives great besides i have a transfer case problem,leaks outta the back seal think its empty thats why it don't work, and a minor steering problem, its kinda hard to steer left, but other then that i drive it everyday,

 

[MariposaBronco]

could the problem be though since it has factory a/c but all that was removed person who did it before me took it out, and took something needed out?

you said that the truck had factory A/C. on the dash the lower slide lever controls the flaps in the heater case allowing air to pass through the heater core. The top lever on the control panel controls the heater valve(vaccum operated), it sits inline on one of the heater hoses, opening the valve & letting hot water flow into the heater core. the top lever on the control panel also regulates where the air flows too ! ( the defroster, the dash vents, the floor, all vaccum controlled). also if none of the vaccum flaps work, the main line going into the cab could be disconnected or missing. if these work thats good. If your heater transfers up to the defroster vents when you are at greater that half throttle the one way valve in the main vaccum inlet hose is bad or missing.

I hope this helps you

if you have any other question feel free to ask me.

P.S. Some heater cores only flow one way. make sure the hoses are routed correctly. I will look at mine it is unmolested. and let you know.

 

[blindside56]

it doesn't have one of those heater control valves in the lines...and i have had the hoses both ways and the same thing arises, this issues is a mess, the selectors work i can change the air to all the vents the only thing that is odd is when the blower is on and turn it to heat the air seems to be less verses when its on cold i don't know why that is, the weather has really sucked where i am at and i have no garage to pull it in so i just been lazy in tryin to tear into it more, plus tryin to figure out more about it and what could be the issues, thanks for all the help but still nothing so i donno? only thing that sucks is i went and played in the snow and heat would be nice to have in that, even if its a lil