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SOme time ago I noticed that my engine heat guage was remaining unusually low. Even in summer heat, stuck in traffic, the guage wouldn't even make it up to the "n" in "normal." I thought I was simply blessed with a very effecient cooling system, until it got cold enough that I needed to turn the heater on, and no heat ever came out.

I figured it was just a thermostat stuck in the open position, so I replaced it. When I pulled the housing open, the old thermostat came out in pieces, so I replaced it, figured my heat would return. Of course it didn't, so I figured maybe a piece got stuck in the heater core and clogged it.

I spent a few hours earlier today getting it out and checking it, and it was fine. I hooked a hose up to it, and water flowed fine both directions. When I had the casing for the heater core off, I looked at the door that sends air through the core, or blocks it, and the cable for it moved fine by hand.

I'm about ready to give up and just take it somewhere to look at it and fix it, but if anyone has any suggestions I can try before shelling out a bunch of cash, it would be greatly appreciated. Thanks.
 

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The cable shouldn't move by hand - only by the knob on the dash. If you can move the door & cable, then the cable is probably disconnected from the back of the control panel.
 

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If there's hot water flowing through the core and it's cold, it's the directional.
 

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Discussion Starter #4
Just to clarify, the cable was moving by hand when I had pulled the casing for the core off and pulled the red part on the cable out of the white housing for it. When I hooked it back up, I turned the key to the "on" position without starting it (hadn't hooked up all the coolant lines yet) and adjusted the temperature knob, but didn't see any movement in the cable.

After driving it for a bit, I pulled the glove box back out and touched the casing. It was fairly warm, but not hot, so it's getting flow through it, I'm just not sure if it's flowing 100%. More than likely, I think it's just not getting air through the core, but I'm not entirely sure how to go about diagnosing which part is causing it and/or how to fix it.
 

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STEVE83 has this REALLY COOL CD for like 5 or 7 dollars. Talk to him about it for your 93. Every diagram you could think of.
 

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I was getting crap for heat and the motor was not blowing all that hard and like you my motor runs pretty cold ( i dont think the tstat ever opens *winter time*)

But... I pulled the fan motor out and stuck my shop vac in there and sucked up all the leaves and dirt, and put it all back together with no good outcome.I then flushed my HC... nothing. So I then pulled the plastic casing from infront of the heatercore and left my truck running till she got warm and held my hand on the heatercore...75% of it was blowing hot air... in one corner it was blowing COLD air.... hehe.

Picked up a new HC for 25 bucks.. pulled the old HC flushed the cooling system, then installed the new HC..... I got HOT AIR woohooo !!
Now my only problem is I cannot select (Floor...Vent...Defrost...Mix) it just comes out of all of them... O well... I got HEAT !!!
 

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Re: Heater issues too

Sigh. Reading issues like these make me wish I had half a clue. My heater went out like a year ago and then I got an oil change (no I dont even change my own oil) and the heater worked again. Then months ago it went out again and I want it fixed but I don't really want to pay for it if I don't have to. I certainly don't want to take it in to a shop and have them school me for more cash.

I printed out everything here since these issues sound just like mine. My temp gauge forever sits on HOT or COOL. Mostly HOT. It goes down to 3/4Hot when I accelerate but when I brake it goes all the way back up. I remember the first time it happened I was stuck in bumper to bumper traffic on a bridge freaking out that my truck was overheating.

Anyway. Just looking for answers and reading threads. Wonder if this worked for the original poster.
 

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Post YOUR specific symptoms. All of them. What exactly does "went out" mean? The blower doesn't blow - the heat isn't hot - what? Have you ever checked the temp with a thermometer in the radiator, or an IR thermometer, or an aftermarket cheapo temp gauge?
 

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Re: Heater issues too

Ok Steve - my specific symptoms are that the blower definitely works but no heat comes out. No I haven't checked the temp with a thermometer in the radiator because I'm not well versed, or versed at all, in the world of Bronco repair. Although I come here because I think it's cool and would ideally like to be.

I printed out that diagram but can't figure out which end is up. Is that whole diagram just for a specific section under the hood or is it bird's eye view of the whole front of the truck?
 

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Lick my balls
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It could be a few things. First, take the rad cap off, start motor and while observing
the coolant in the rad, let it get to operating temp. Keep the rad cap handy. As soon
as you see the coolant moving put that cap on asap because it will start to pour out.
Now we know your thermostat works. Next, go over and feel both hoses going to the
heater core. They should feel the same (temp wise). If one is cooler than the other,
you need to replace the core. If that works then check to see if when you move the
temp lever that you first, feel resistance and second that it is connected to a lever
down by the passengers feet, up towards the glove box. That's about all I can think
of right now, good luck
 

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Mine is wierd. I can move the lever to change it from the floor to the defrost to anything else but it won't work for some reason. It will go to off and actually go off but it won't change to anything other then just the vents blowing hot air so my legs get cold and I cant defrost the window! I am thinking it might have something to do with the cable or something inside...
 

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BroncoDoug said:
Mine is wierd. I can move the lever to change it from the floor to the defrost to anything else but it won't work for some reason. It will go to off and actually go off but it won't change to anything other then just the vents blowing hot air so my legs get cold and I cant defrost the window! I am thinking it might have something to do with the cable or something inside...
Sounds like the cable isn't hooked up. I don't think your truck will have a vacuum diaphram for defrost.
 

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Yes, ALL of our trucks have vacuum motors for the distribution doors exactly like Rob's diagram, EXCEPT '87-early 88 (and mine because I swapped that style in). Only those 2 years used a cable going to a compound lever for the distribution doors. ALL use vacuum for the recirc motor & ALL use cable for the temperature blend door. Doug, yours is a vacuum problem - check the 2 lines (1 Wh, 1 Bk) under the R hood hinge going thru a grommet with the wiring harness. These pics are the rare '87-88 style.

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Jerkey
The diagram is a schematic, so it's not to scale, or from any particular perspective. The horizontal line thru the lower diagram that says "Dash Panel" is actually the firewall, so it's sort of veiwed as if you were standing on the dash up thru the windshield looking straight down. Above the line is under the hood; below the line is inside the dash. But all the vacuum lines that come from above are actually inside the dash, too.

The dotted lines are mechanical connections; the one from "Temperature Control Lever" is the cable. The others are bellcrank levers sticking up thru the duct housing that the vacuum motors pull/push on.

I'm reposting Rob's diagram for reference, but check the thumbnails below.

. . . .
 

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Wow that is so awesome - thanks Steve83 and Waltman - that's all great advice and I love the pictures. Gave me a great idea of what I'm looking for. I'm going to spend time on all of that this weekend and hopefully will have good results.
 
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