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david7w5

Need heat in my Cab

30 posts in this topic

I did the radiator cleaning back in the summer and brought the temo back to 190 pulling, boy was it nasty. Well its finally getting cold in GA and i turned the heat on and its blowing cool air. I cleaned the rad, new thermostat, and cap. Any ideas on why its not blowing hot ?

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Do the heater hoses get warm? They both should get warm no matter where you have the heat control. It could also be a blend door issue too. This will explain what is involved with the blend door: http://dodgeram.info/tsb/2003/24-004-03.htm

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Does air come out of the correct vents? If air comes out of the defrost, regardless of the control position, it's the vacume powered control. Could be a bad vacume pump, vacume leak, disconnected line or bad control drivers side of heater box. If you've been working under the hood, check vacume lines first... easy to distrurb or sometimes break. If air does not come out warm but comes out in correct place, likely electric blend door over passengers foot well. Hard to get to but can be done. See http://www.heatertreater.net/ Hope this helps. Russ

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What I did when I had problems getting enough heat was flush the heater core. I filled a 5 gallon pail nearly full of hot water and mixed in a bunch of rad flush stuff, hooked a little pump to one side of the heater core, and circulated it thru for a while. Sure did the trick for me but I also knew my blend door was moving some at least since I could get lukewarm air.

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Not sure of anything yet, I do know that it switches between defrost, panel, and floor. But i have too dig further this weekend.Thanks everyone

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Have you checked your coolant level? A blown head gasket could cause that.

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Cold.......in Georgia!!!!!!!:lmao::lmao::lmao2::lmao2: What happened, did it drop into the 50's????Good advise up there!!:thumbup2:

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Ok I have checked everything and seems to be working fine, The heat gauge doesn't hit 190 and I put in a new thermostat when cleaned everything. I read somewhere that a superstat thermostat is not a good design and will let water bypass and cummins has a patten on there design, but I can't find it again. Should i find a cummins brand and replace? When it was warm (60+ degess outside) it would go to 190+ and then drop, but now that its 30-50 degrees outside it doesn't hit 190 degrees. could this be my heat problem and should I have a winter screen in north GA. I do plug up when its below 40 just from keeping it from ideling all morning.

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What kind of driving are you doing?????? Around town, stop and go...........or highway cruising.........towing???? The cooling system on these trucks is so good/efficient/large that even towing around town in cool weather, won't bring the engine temps up.Idling will drop the temps a lot..........even in "HOT" Georgia weather!!! I remember towing a 25' car hauler loaded 3 ATV's and hunting gear for 5 guys in -10*F temps and into a straight 25mph North wind. No winter front at the time. Boost was running 20lbs.+, the EGT was 900-1000*, but the coolant temp was barely over 190. Stopped for fuel, and in the 10 minutes or so it took to fill up, the coolant temp dropped to under 160*.

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I'm still running the OEM thermostat. Temp goes to mid guage & pretty much stays within a needle width of that spot when I'm running. A winter front shortens the time to reach that temp but the motor is still running on the thermostat.

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Not to hijack but it appears that more than one person has the lukewarm heat issue im just mainly to lazy to tear my dash apart and find out whats really wrong but my random thought for you to check and question is when does you ac compressor come on and turn off I have come to find that this appears to be my problem simply because it only turns off when the selector is on the feet and that is the only time i get good warm air my other thought is maybee superstats do suck just put a new one last week and got my winter front in and when im in town in 10-20 degrees I will barely see 175-180 then on the highway I will see 205 or better. my winter front is also not visible from the outside since it goes between the intercooler and the radiator thus keeping egt's down big time... hope this helps as I said all I know is that this ac compreesor is running all the time and I know it should when its above freezing on defrost mode but it doesnt explain why when ac is on max and the regular setting it'll freeze u outta there then when i switch to the blend feet/chest ac off obviously selection it stays kinda cold and the compressors running but its not nearly as cold as when the ac was on... :shrug: as i say to my friends wit my truck it get to 50 60 in the cab so grab a jacket :)

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Not to hijack but it appears that more than one person has the lukewarm heat issue im just mainly to lazy to tear my dash apart and find out whats really wrong but my random thought for you to check and question is when does you ac compressor come on and turn off I have come to find that this appears to be my problem simply because it only turns off when the selector is on the feet and that is the only time i get good warm air my other thought is maybee superstats do suck just put a new one last week and got my winter front in and when im in town in 10-20 degrees I will barely see 175-180 then on the highway I will see 205 or better. my winter front is also not visible from the outside since it goes between the intercooler and the radiator thus keeping egt's down big time... hope this helps as I said all I know is that this ac compreesor is running all the time and I know it should when its above freezing on defrost mode but it doesnt explain why when ac is on max and the regular setting it'll freeze u outta there then when i switch to the blend feet/chest ac off obviously selection it stays kinda cold and the compressors running but its not nearly as cold as when the ac was on... :shrug: as i say to my friends wit my truck it get to 50 60 in the cab so grab a jacket :)

Not sure why it is running that much. Mine doesn't turn on at all unless it is on defrost. I had it on recirculate today and the temp gauge went over 160F coming out of the center vent, my temp thing goes blank after 160 lol. I did get a pic of it before it blanked out. I could barely grab the steering wheel because the vent was blowing on it, scorching my hand.

post-45-138698173455_thumb.jpg

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I guess I have confirmed that the ac conpressor is causing the problem only because I borrowed my buddys temp gun and the two heater hoses were around 180 each then inside my air comes out at like 95 degrees I thought it was my core but so I flushed it and no change not to mention the hoses being within ten degrees of eachother is a good sign I guess I just now have to figure out whats up with the ac compressor cheap fix someone recomended was buy a new belt for your truck without ac and just eliminate it for the winter my thought was is that going to harm anything such as defrost and such and can I just do that or is there something else involved? thanks much for the help in both threads isx :thumbup2:

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my AC compressor cycles using every selection(or so i think). on 2sec off 5sec. always thought that might be a source of lower MPGs but do not wanna hack the harness for a toggle switch.

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Thanks much I'll give her a go and see what I get :shrug:

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Thanks much I'll give her a go and see what I get :shrug:

I was outside earlier and pulling that connector does turn it off. I had A/C on and everything and hooking the switch up made it come right back on. A lot simpler and cheaper than a new belt :lol:

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Fixed her right up and I got what I was after heat :thumbup2: lol now comes the fun part of figuring out where the system is mucked up because Im gonna guess the compressor itself is good maybee a bad controler :shrug: with the belt off the clutch seemed alright but im not so much an a/c guy at all

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Not sure why it is running that much. Mine doesn't turn on at all unless it is on defrost. I had it on recirculate today and the temp gauge went over 160F coming out of the center vent, my temp thing goes blank after 160 lol. I did get a pic of it before it blanked out. I could barely grab the steering wheel because the vent was blowing on it, scorching my hand.

You would think that if your coolant is 170 then the air should be at least 100, but mine only gets warm enough to defrost the windows. I'll have to check my mix control

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You would think that if your coolant is 170 then the air should be at least 100, but mine only gets warm enough to defrost the windows. I'll have to check my mix control

I actually get a exponential curve going for vent temps (non-recirculating) and coolant temp. I don't know my exact coolant temp until I get to 130 but I can watch the vent temp shoot up from the time I start it. Meaning that I am getting probably the same temp out of my vents as the coolant is. As the coolant gets warmer, then the 2 relationships start to take different paths. From what I can figure, cold air takes on heat more readily than hot air, so any heat in that heater core while the cab is still freezing is going to be easily pulled away by the moving air and blow into the cab. However, there is a point when the heat from outside reaches its limit because of the velocity going through the heater core. You might notice you get hotter air on setting 3 than 4 because it isn't moving as fast so has more time to grab more heat, but then you aren't getting as much flow so it probably works out to heating the cab the same amount. On recirculate, it runs the already hot air through the heater core and you would think it would pull the entire 190F heat out of the heater core, but it doesn't. I have seen around 160F max on recirculate but the temperature difference isn't enough for it to get much more heat than if it weren't on recirculate. It is like a swimming pool being 100F and the air temp being 90F, that water isn't going to cool very much because there isn't much of a difference. Let it get to -10F and now the pool freezes rather quickly. You can put the fan on the lowest setting and that will give you the highest temp since it needs all the time it can get to pull the tiny difference of temperature away from the heater core, but then you have no flow. It is a very tedious setting if you want the most heat, vent settings even come into play (head/defrost/floor/mix..). Recirculate gives the hottest temperature no doubt, but only on your head so the bottom half of the cab remains cold. What I have found to do is put it on recirculate (setting 3) until your head melts, then put it on head/floor (setting 4), the temp will be a little lower but the whole cab will unite as one perfect temperature and then you simply start stepping down on fan speed, then temperature. The only thing is that the 24V's have that compressor on on every setting almost. I will turn my a/c on when it is on the head vent non-recirc tomorrow and see if it drops the output temp.
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Finally figured out what was wrong with my heating/AC system. The "blend door" was stuck. It would open from time to time but not on any regular basis. Took it back to the shop who worked on the whole system and they yanked the dash out finding the problem. Seems that there was a burr on the door that kept it from moving right.

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Not sure why it is running that much. Mine doesn't turn on at all unless it is on defrost. I had it on recirculate today and the temp gauge went over 160F coming out of the center vent, my temp thing goes blank after 160 lol. I did get a pic of it before it blanked out. I could barely grab the steering wheel because the vent was blowing on it, scorching my hand.

Is there any difference from 12valve to 24? Are the heaters different too? I don't have recirculate unless its on max AC

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