LUVTruck.com

I have an odd problem with my heater in the Luv. I can put it on defrost and turn the fan on high and get pretty good heat out of it. I put it on heat and leave the fan on low and get pretty warm air, if I turn the fan on higher the air temp gets really cool and will not blow warm air Engine temp is in the normal range, and I just put in a new thermostat, 180 degree.. Is there some sort of way I can fix this, I am freezing my ass off..

Yeah, move further SOUTH
LOL j/k

may try replacing your heater core:

since i dont know the year of your truck i just used mine but they should be the same:

http://www.autozone.com/servlet/UiBroke ... n=loadPage

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I like my steak like I like my women, young, tender and bloody.

All I need is my weed, women, and wine. -Edge City Outlaws

why would I be able to get heat out of defrost and not heater if heater core was bad Wouldn't mind a little warmer blue, but it doesn't sound like your weather is a whole lot better

crap...i missed that part...sorry

have you checked all the controls and cables to see if they are working right?....maybe it aint fully switching. therefore on sending 1/2 the heat to each area.

there is also some kinda heater control valve on the firewall on the driver side..maybe its not opreating right

where the hell is 800xl w/ a 1/2 page post?

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I like my steak like I like my women, young, tender and bloody.

All I need is my weed, women, and wine. -Edge City Outlaws

I had a similar problem on my '79- heat but no fan on high setting. Took apart the heater cover, and found a single pine needle arcing across the coiled wire resistor in there. Must have come down through the cowl intake somehow. Picked it out of there, and has worked fine since. Weird, but cheap to fix.

No problem, I have noticed that when it is on heat that I still get air to defrost also, is this normal?

I have fan in all settings, just that the air gets cold when I turn fan speed up

hmm....larphead might be on to something there. Lots of control cables for the air diverter door & the heater control valve down there. I've seen other posts about that valve. It may be froze up, and the cable is bending, kinda like pushing a rope.

It sounds like one of two things to me:

1) Not enough hot water getting through the heater core. Seems ok on defrost but on heat it gets more air flowing over it and cools down. Could be clogged or the valve on the firewall isn't opening enough. Not my favorite option but could be a contributor to the second case.

2) Broken/missing/maladjusted heater controls. When you run the lever from defrost to heat and then over to vent, you are moving several control cables that open and close air flapper valves. I think something in there is not working quite right, so the vent flapper is opening too far towards the heat/defrost side of the controls. You start at defrost with hot air coming out, move towards heat and some air starts to come out the heater, further along but still not to heat setting and you get cold air as the Vent setting starts to open up, but the heat setting hasn't come by and closed off yet. (whew) So, you got cold air bypassing the heater core and dumping out instead of going through the heater and coming out toasty.


Now the fun part, all this is theory. I've never had to (or wanted to) tear into adjusting more than the hot/cold controls. My current 79 kinda starts to blow cold if I set it right on HEAT, so I just leave it a tad towards defrost. I started to look back in there once and decided I'd rather wait for warmer weather to mess with it. Its a complex maze of stuff all tied together. I'd rather keep the heat I have now, then fix the problem when I can risk running with no heat. Yours sounds like it is off on both the vent and defrost settings, though normally a bit of air still comes out the defrosters when set to HEAT. I think you are just going to have to dive into adjusting things and see what you can get. Basically you look for cables leading in/out of the controls and adjust them by moving the jacket back/forth where it is clipped in. I'd offer more help than that if I had it. This is one of those things that is just not easy to explain, you kind of have to jump in.

I have a heater problem to. I dont have any valves on the firewall just straight to the core. My engine gets up to opreating temp. and it still blows cold air. Then when it almost gets to the point of overheating it gets warm. Then it dies of in less than a minute. I have already put a garden hose to push water through my heater core and it goes through. I dont know what is wrong. Does anybody else know whats wrong?

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try like i did! flush the heater core out! my '79 did the same thing!all you have to do is determine witch one is the outlet pipe. should be the one that is cold then the engine is hot and the heater is suposed to be working anyhoo flush strait water thru the core backwards to get all the coolant out first. then after its all out make shure its as full as you can get it and blow compressed air thru it. that'll blow the debris thru it most likely. if not hook everything back up and run a coolant flush treatment thru the system.......... my luv only had hot air when it was on low and only out the passenger side floor vent now. now it'll cook you're feet from the tail gate

I fixed it! I took the heater hose wich was on the radaitor and moved it next to the water neck. Works great now.

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good deal, you have a v-8 but are running the stock heater hoses and core, right?

dels78, It sounds to me like a door or flapper under the dash that switches the air from def. to heat is not moving freely. I have not been under the dash on my luv, but generally speaking thats where I would look.

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OK, I'm over it. Where's the beer?

Well I dont have the stock heater hoses but yeah I am still running with the stock heater core.

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well it sounds like I have some lookin and flushin to do on this but it'll have to wait until it warms up a little.