heater in fj40 nonfunctional

[orange40]

this morning i picked my truck up from my mechanic,its a 1977 fj40 2f 4spd .we had been working on the cruiser off and on when we could afford , for 3 yrs .went through most of the truck, so today was really the first time i ever drove it being real close to being done, well the heat didnt work,the 30 mile haul from machias to my house was ,''a real treat'' :'( the air temp was -3 . the blower works , the rear heater got sorta warm, i kept putting my hand on it ,just warm, the front heat blower was cranking, real cold air, we could have run snow making equipment inside the cruiser. do you guys think its the heater core or heater valve or both, or was it so damm cold that no heater made would have saved my sorry azz? the truck had a 30 minute warm up. any help would be greatly apreciated. my ol'lady is gonna be in for a surprise when she trys to swipe my cruiser and stick me with her volvo wagon,

 

[dinkleberry]

heater in fj40 nonfunctioal

Heater valve, Low coolant, or the duct from the blower to the core not sealed well.

That's where I'd start.

 

[Frederik]

Re:heater in fj40 nonfunctioal

Open the hood an find the valve that controls the flow of hot water (should be on the firewall) Check if hot water can pass through easy (feel the temp on both sides) That was where my problem was...

 

[orange40]

heater in fj40 nonfunctioal

wow , quick and efficent. thanks guys im going out right now ill keep you posted.

 

[Landpimp]

heater in fj40 nonfunctioal

check to make sure the valve on the firewall is opening up, spray it with some penatrative stuff, prolly stuck closed after 3 years.

FWIW, the early cruisers had a shut off valve on by the lower radiator hose, check to make sure for some reason your might have one(it shouldn't but who knows) I am adding one to my 82 because the heat never really shuts off. also is handy if you loose a heater hose, just close it off. Some also had a 2nd valve on the back of the head.

if its a heater core, you can get a new one for $100, easy to swap.

JohnH

 

[kacers]

Re:heater in fj40 nonfunctioal

I second Pimp's reccommendation. My '80 FJ40 sat for 3 yrs before I bought. Heater worked twice and then froze on me. Sprayed PBBlaster (or Kroil) into the heater valve and worked it around by pulling the heater knob on the dash. Worked free in a few mins and ....voila - heat. Hasn't frozen again yet (6+ months of daily use in the NEast).

Check and make sure the heater cable (from the dash knob) is connected properly to the heater valve. If it is, next try pulling the heater knob and make sure the heater valve opens and closes as it should. If it doesn't, you need to unfreeze it with PBBlaster or Kroil. If it does, you have a different problem.

 

[orange40]

heater in fj40 nonfunctioal

while outside getting the truck up to temp i noticed that the rear heater fan wasnt running, am i correct to asume it is supposed to come on when i pull the lever that says pull fan? the front blower cranks, but nothing in back, fuse? i have a spare heater box that goes up under the hood, where it all starts. can that blower motor be cannibilised to make the rear run ? the piping coming in from the engine has gotten nice and hot, the heater valve seems to be working good ,just no rear fan and no heat of use is coming out the front . starting to sound like core? thanks bill

 

[Pinion]

heater in fj40 nonfunctioal

I had to take my rear fan apart and fix the motor as it had siezed and was smoking. The bottom bearing had no grease in it and the contacts were shot. I fixed it myself though. When you pull that switch the fan should kick on. It took about 10 minutes to fix.

Sounds like a core problem. Have you pulled the top off of the front heater box? If it has sat for a loong time, pull the hoses and look at the top of the core... It could have a mouse nest in there... if not, it could still be fouled with lots of dirt and dust and just about anything else.

HTH,
Rob

 

[kacers]

Re:heater in fj40 nonfunctioal

Help us out here - your first post said you did get some warm air out of your rear heater. Than above you say the rear heater wasn't running. FYI - the fan pull has two setting: low and high. High is the second click as you pull out the knob on the dash. You have to be on high setting to get the rear heater to engage. So, make sure you pull the Fan switch out all the way when checking if your rear heater is working. There is a front resistor also near the front blower that you probably want to check.

 

[kacers]

Re:heater in fj40 nonfunctioal

Note - front and rear heater run off the same fuse. So if one works - its not the fuse. The resistor I believe is used to limit the power output for the low fan setting. If your blower stops when you put the fan on high - then your resistor is probably bad. HTH.

 

[kacers]

Re:heater in fj40 nonfunctioal

correction to above - if your fan runs on High but not on low - than your resistor may be bad. My post above (typo) had it backwards.

 

[orange40]

Re:heater in fj40 nonfunctioal

[quote author=Andrew link=board=1;threadid=11665;start=msg106296#msg106296 date=1077050664]
Help us out here - your first post said you did get some warm air out of your rear heater. Than above you say the rear heater wasn't running. FYI - the fan pull has two setting: low and high. High is the second click as you pull out the knob on the dash. You have to be on high setting to get the rear heater to engage. So, make sure you pull the Fan switch out all the way when checking if your rear heater is working. There is a front resistor also near the front blower that you probably want to check.
[/quote]sorry i meant to say that the rear blower wasnt working but core was good and hot , then i dug real hard around on the floor found i disconnected wire going to rear fan only 2 of three wires were connected . meanwhile up front the heat comes out after messing with the levers ,and loosening the heater valve like you all stated , i got some heat out of it.it seemed the valve worked but not all the way . so its freed up now. only real thing im wondering now is would i get more heat if i replaced core? or should i be just real glad i get what i got out of it ? or would a good vacuuming the fins and the box be what i need? thanks for all your speedy replies, you all saved me a couple of real cold hours out in the yaaahd. Bill

 

[Pinion]

heater in fj40 nonfunctioal

Run some rad. flush through it... but I will bet that if you havent blown out the fins with compressed air or vaccummed it, the PO's didnt either. Give that a shot.

 

[sherwood]

Also, don't forget to check that thermostat and it's associated gaskets.
It's not uncommon for the PO to install without the top gasket.

John Sherwood '79 FJ-40
Charlotte, NC

 

[orange40]

[quote author=sherwood link=board=1;threadid=11665;start=msg106349#msg106349 date=1077058125]
Also, don't forget to check that thermostat and it's associated gaskets.
It's not uncommon for the PO to install without the top gasket.

John Sherwood '79 FJ-40
Charlotte, NC
[/quote] thanks john,its funny you bring up the thermostat when we went through the entire cooling system ,we found there was no thermostat in it , there is now , brand new. but whats up with that ghetto s***? have you guys come across this ?

 

[sherwood]

I guess it's either because they were having overheating problems and couldn't/didn't want to spend the money on a replacement ...... or...... didn't understand how it functioned ..... or ...... (as in my case) the thermostat fell apart into 3 pieces. Again, that upper gasket is very important. Might as well not even have the thermostat in there if you don't have the proper upper gasket. (also, seems like I recall some folks posting a long time ago about having a problem with a "too thin" aftermarket upper gasket ?)

Can make a big difference in heater output temp in cold weather.

John

 

[Eternal]

I have cleaned and flushed and done just about all i could to my heater and the thing never could put out enough heat. After 9 freezing winters and having to use the ice scrapper more on the inside than the outside I have finally purchased a aftermarket 36,000 btu 3 spd htr that is used for front end loader/skidders/etc. and it is small fits nice under the dash and pumps the heat. It was $125 CDN and worth every penny. Just something else to consider if cleaning it doesn't do the trick. Best of luck

 

[Travis_Kinney]

There a cable that runs from teh dash to a valve on the heater house under the hood that controls the flow. That wire might push and pull and that little lever on teh valve rotate back and forth, but the ball valve inside might be rusted into one position only letting a trickle flow through. You touch the heater hose in the cab and it is warm because you have some flow. I took my valve off and connected the two hoses with a platic barb connector. Nothing to stop the flow now. Hose inside the cab isn't warm, it's damn hot! If your heater core isn't leaking, don't replace it. There;s nothing wrong with it, it's just a lump of metal with lots of passages for water to flow through. You could yank it out and take it to the sink and try flushing it incase there crap particles in it. My guess is that you don't have the flow.

 

[DenverCruiser]

Should mine have a heater valve? My 69 doesnt look like it has anything. I cleaned out the core a few months ago so I know it is good and it is blowing like crazy but just not as hot as it should be.

 

[Poser]

Posted already in your 'knob' topic, but..

You will not have a cable controlled heater valve for the coolant, unless someone fabbed one in like the pic above. Your heater vavle should be located on the rear of the cylinder head, where the heater hose hooks up to the engine. The earlier trucks, from my expierence, pre-67, had the heater valve in the pipe seperating the water pump and the radiator...

I have also seen many forms of kustom installs of heater valve controls, located anywhere in the heater lines between the engine and the heater core. I would look at where these lines connect to the engine, and trace them back to the core, and see if there is in fact a valve that is not opened, causing this issue.

Another thing that I would verify is the rubber boot that connects the heater core and the heater duct. If the core is hot, and you are not getting hot air out of it, it could be that the air from the blower motor is not going through the core, and is just dumping before it gets to the core..

Good luck!

-Steve