Okay, so I'll try to describe the situation as best I can. When I bought my truck, the heater was cut out of the coolant flow loop, so the hose went out of the engine and straight back in. The second hose was just tied into the engine, but not connected to anything (for storage, I guess). Anyway, since I bought it in June 07, I didn't need the heater and didn't do anything about it until October of that year. It started to get cold, and I needed my defroster, so I plugged the second hose it and completed the loop. All went well: My heater heated, the defroster worked, good stuff. But, I noticed that a white fog spread over my windshield from the defroster vents while I was driving. This only occurred when my defroster/heater was off. I've heard that a cracked heater core can cause this sort of thing, is that what it is? I've had the heater disconnected since about April, but the time is coming to when I need it again and I'd like to know how to fix it before I run into a tree or something.


Also, in a somewhat related note, keeping the defroster on all the time would solve the issue to some extent, but my temperature control slider spring is broken and stuck on full heat... it's not comfortable driving around in a 110 degree cab . Does anyone know where I can get/how I can make a spring? Looks like a big paper clip would even do the job...

 

My windows fogged until I replaced the heater core,so you are on the right track.

 

replace the heater core. you dont say what year and w or w/o AC?

 

Sorry, it's a 1983, and there's no AC. Thanks for the advice too, everyone. How much would a new/slightly used heater core cost me, and how involved is the replacement?

(And still curious about the temperature adjustment slider situation).

 

New heater cores are only about $30.

They are a PITA to change though.

You have to remove your glove box to get at some of the bolts. The entire assembly had to be taken off the fire wall to change it.

 

The whole job should take about 3 to 5 hours.

That's draining the coolant, removing the heater assymbly from inside the engine compartment, replacing the heater core inside, putting it all back together, flushing the system and adding coolant.

Would also be a great time to change the hoses and belts.

You may need to remove the glove box, and door to get at some of the nuts holding the heater assymbly on.

This diagram should help some. And once the heater assymbly is off the cab, replacing the heater core is self explanatory.

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As for the temp control, it's most likely either a froze or busted control cable.

There are numerous different heater controls between the years and engines, but I believe the following diagram best matches your year model.

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The heater core should be fairly inexpencive at the auto parts store of your choice, so buy a new one. Also I recommend going to a high end auto store, such as Napa. The parts are more expencive, but so is the quality.

As for the heater control assymbly, or cables, last time I checked for my truck they were a Ford Dealer only item, and was obsolete. So a wrecking yard might be your only chance for this item. Check around though, things change all the time.

 

Alright, thanks for all the tips. One more thing: How do you get the radio ***** off? I've seen many places that they should just pop right off, but I've tried and it seemed if I pulled much harder, something would have snapped. Once I can get those out, the main console would come off easy, and access to that pesky temperature control slider would be simple that way.

 

The ***** just pull right off.

There is nothing but friction holding them on.

 

Too bad you don't have air conditioning. Replacing the heater core is a 30 minute job on those.

 

You said the truck has no a/c, so that changes the way the core is set up. If it says anything about high output on the heater box, the core is under the hood. It is a bit more trouble to get out than the a/c under dash units are.

 

Here's another diagram of the Radio assymbly.

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As Uncle Stosh said, the ***** just pull off. But if they haven't been removed in 25 years, then you might need to use a screwdriver to pry them off. Be careful or you can damage things. Only use the screwdriver as last resort thing.

I also recomend removing the Ash Tray, and glove box, giving you more access.

 

One last bit: How do I tell if I have a regular heater vs. a high output one? Or does that not matter when dealing with the core alone? I'm just trying to get everything straightened out as I plan to put the new core in this week, and I want to be sure I buy the right stuff to save trips to the store.

 

The easiest way to tell is the High Output Heater Box, will have "High Output Heater" stamped on the box under the hood.

If it doesn't have High Output Heater stamped on the box under the hood, then it's safe to say you have a standard one.

 

what is the difference between the high output and the regular one
(sorry for the stupid question if it is one)

 

The Heater Core is different, Larger. So is the Heater box under the hood.

Some are also vacuum controlled simular to A/C models.

They are mostly found on trucks built in canada, or in colder mountan states like Minnesota, or Alaska.