Heat not hot….

[70newport]

So I went through an issue with no heat at all last winter, turned out to be the blend door actuator. (Aftermarket ones don’t work) I flushed my heater core all seems to be good with it, but I don’t have Hot coming through the vents, I have warm. I didn’t notice it to be that bad until I ended up with a rental truck for a couple days while mine was in the shop. Any suggestions would be great.

thanks!

 

[1999 White C5 Coupe]

So I went through an issue with no heat at all last winter, turned out to be the blend door actuator. (Aftermarket ones don’t work) I flushed my heater core all seems to be good with it, but I don’t have Hot coming through the vents, I have warm. I didn’t notice it to be that bad until I ended up with a rental truck for a couple days while mine was in the shop. Any suggestions would be great.

thanks!

Warm (not hot) heat output can be caused by low engine coolant and a stuck-open thermostat (causing a slow engine warm-up).

Are you sure the coolant is at the proper level?

The slow-warmup (due to a stuck-open thermostat) will often set a stored trouble code, but will not illuminate the check-engine light.

 

[jejb]

There are usually more than one blend door actuator. It could be one of the others has gone out.

 

[RamCares]

Hey there,

If you decide to take your truck to the dealer for diagnosis and repair, please send us a direct message. We'd love to get you an extra layer of help.

Callie
Ram Cares

 

[Dean2]

Outside the suggestions provided I can't think of anything else. Low coolant, bad thermostat or actuators not working is pretty much the only things that will affect heat in Cab.

If you can't find it yourself and you are looking for a top notch independent shop give Arena Auto in the West end a try. Gil has owned and run the place for 45 years. Honest as the day is long and his guys are well trained, not on commission.

780-453-1805

11615-163 Street NW Edmonton, AB T5M 3W6

 

[70newport]

Warm (not hot) heat output can be caused by low engine coolant and a stuck-open thermostat (causing a slow engine warm-up).

Are you sure the coolant is at the proper level?

The slow-warmup (due to a stuck-open thermostat) will often set a stored trouble code, but will not illuminate the check-engine light.

Thanks for the reply, I checked coolant level and the truck seems to get up to temperature in about 5 minutes unless it is obscenely cold out so i assume the thermostat is still good, any other way to test this?

 

[70newport]

There are usually more than one blend door actuator. It could be one of the others has gone out.

Thanks for the reply.

My truck being a base model has 2, one for direction and one for temperature (from everything I could find) both were replaced and I actually swapped the 2 locations as a test with no change.

 

[Jeepwalker]

Two things:

1) You might want to hit the water neck outlet (upper radiator hose), with an IR temp gun and see what the truck is actually operating at when warm. There are two temp sensors (one for the gauges).

2) Actuate the blend doors with that scanner and check for hvac codes. It'll take a better scanner to do that. IDK if Autozone or OReilly's would work..worth a call. As mentioned above, you might have another blend door actuator which is faulty. Or, it's possible the hinge itself on a certain blend door is partially broken (cooler air leaking past). .

 

[70newport]

Two things:

1) You might want to hit the water neck outlet (upper radiator hose), with an IR temp gun and see what the truck is actually operating at when warm. There are two temp sensors (one for the gauges).

2) Actuate the blend doors with that scanner and check for hvac codes. It'll take a better scanner to do that. IDK if Autozone or OReilly's would work..worth a call. As mentioned above, you might have another blend door actuator which is faulty. Or, it's possible the hinge itself on a certain blend door is partially broken (cooler air leaking past). .

Both good suggestions thanks! I will try those asap and report back. I for sure dont have a scanner that goes that in depth.

 

[jws123]

Both good suggestions thanks! I will try those asap and report back. I for sure dont have a scanner that goes that in depth.

Is the passenger side hotter then the drivers side? If no codes for hvac when you scan it and verify doors work. Thats a very good indicator its time for a heatercore they clog up on 4th gens for no apparant reason have never been lucky to un clog one yet I have replaced about 10 so far in 4th gens for hotter air on pass side then drivers side.

 

[70newport]

Thanks everyone,

Truck was in a minor fender bender thanks to a lady that changed lanes into me so I can’t double check these things. Will do and post back asap.

 

[ctwalton15]

just putting my 2 cents. I had a similar issue in my 09 ram. Replaced all of the blendoor actuators, my truck has 4. 1 recirculation which you cannot access without removing the dash: on the passenger side of dash and on the left side of the heater box, 1 Temp control, the one behind the glove box, 1 defrost and I believe the other is a floor actuator - both of these below the radio. I only had heat on my passenger side last winter then about 3-4 months back no heat period so I replaced all actuators, no change. Took it somewhere because I needed to have something done that I couldn't do and said screw it, told them to take a look and see what they recommended. They told me a slight blockage in the heater core but both hoses still hot to the touch. I didn't bother trying to flush it, just bought a new heater core from oreilly's pulled the dash and changed the heater core, while I was in there I ended up doing a AC Evaporator, probably a good idea considering that mine was covered with a bunch of wet mud from the times I've gone off-roading. Anyways, like I mentioned ended up pulling the dash and heaterbox, truly went a lot smoother then I thought. Pretty easier, I think about 8-10 bolts throughout the dash, bunch of connectors on driver and passenger side. Just lift off the hinges and flip it forward onto the front seats.

Btw, I ended up finding my recirculation blend door wires were cut toward the connector. Not sure who, why, or when it happen but had to have been before I got the truck. I ended up fixing the wires and the recirculation works now. Oh, and I've got heat everywhere now.

 

[Jeepwalker]

I have a recirculation door on a Jeep that's broken off it's hinge. It's one of those plastic flex-hinge ideas (lousy idea) ..and when things get to be -20F or below that plastic stuff just breaks after a few winters. What I did years ago ...one cold winter day, was work the recirculation blend door back in position and force it closed with a piece of heavy wire. It solved my wife's cold-legs problem (her DD at the time) during a cold stretch we were having. Since it's never been a hassle of any sort, I just left it in place as recirc isn't very necessary where we live.

What I did was remove the lower plastic grate which then gives ya access to the recirculation air intake damper door (above the passengers feet area). I think it's similar for the Ram, but not 100% sure. Then,, as I said above, I worked the door back into place wiht a long screwdriver ..a dowel would work too. Afterwards I measured the approximate length and fabbed up a piece of heavy wire (14 ga or 16ga??) to hold it in place, I'm guessing it's overall length was 4-5". The wire has a loop in the center (like wrapped around a 3/4" pipe) that allows for constant spring tension. It is sharpened to a very sharp point on each end of the wire, so it 'digs' into the plastic and won't fall out. The exact length you'll have to figure out for your application. I was able to push the wire up into place and the spring tension holds the recirculation damper door firmly closed. Gosh its been 10 years like that(??). It fell out once about 5 yrs ago and took 10 min to get back in place.

If the recirculation blend door is your issue and you don't want to remove the dash and heater box at this time, the above idea could be a potential quick-fix idea (until you're ready to jump into the larger job). Personally, it's never been an issue keeping the recirc door closed. The only annoyance is the blend door actuator 'hunts' because it's programming is to find 'full open' and 'full closed' which it can't ...because the door hinge is broken off the actuator rod. It makes a barely perceptable noise which only I seem to pick up on. After a couple attempts it stops. You ought to be able to hear if this is your problem if the actuator 'hunts' after the vehicle is running, or after it's shut off (makes a couple attempts). If it's really quiet you might hear a squeak noise by the passenger side below the windshield.

But the spring-tension wire turned an arctic-blast situation into a comfy cozy cabin, and that kept my wife happy

 

[70newport]

I had really hoped it wasn’t a heater core issue but tested a couple days ago and drivers side was colder than passenger side. With it being -30 I said to hell with it and took it to a shop who had it back same day with a new heater core ‍♂ At least I have heat now.

Thanks for all the advice everyone!

 

[gofishn]

Glad it got fixed.
-30?
Doubt I'd be messing with it either.

 

[GTyankee]

For me, the Recirculation door can remain closed, when it breaks, the door stays shut. If it sets off a light or makes a noise that is audible, just remove the glove box doors & reach up & unplug the power to the actuator.
If you should want fresh air, because someone passed gas, open a window a bit.

With the lower glove box removed, shine a flash light to the left,
You can see the BLEND DOOR Actuator, you can work the heat controls & watch the actuator move, if it has not stripped a tooth or two on the gear.
The Blend door directs the air to both sides of the cab, there are two doors that are controlled be the blend door actuator.

The 2 actuators that are below the radio, are called MODE DOORS. they control which area that the air will go, defrost, center vents, floor vents

 

[danielrly]

Is the passenger side hotter then the drivers side? If no codes for hvac when you scan it and verify doors work. Thats a very good indicator its time for a heatercore they clog up on 4th gens for no apparant reason have never been lucky to un clog one yet I have replaced about 10 so far in 4th gens for hotter air on pass side then drivers side.

That's a bummer to hear. That's exactly my issue. Hot on passenger side and just air on driver side. Driver side seems to have less air as well. If I turn on recirculate air the driver side seems to get warm/hot. For some reason when I turn on recirculate it automatically turns on AC icon that I have to turn off and leave recirculate on.

 

[Dean2]

Defrost will automatically turn on ac to dry the air, same with recirculate. If you live where it gets really cold, as in anything below freezing, you would leave recirc permanently open or you would never get rid of the frost build up on the inside of your windows. Takes new folks to this area quite a while to learn that one.