Hi Everyone.

Looking for advice on my 07 RDX that isnt putting out any heat. Blower seems to be running fine. Blows plenty of cold air. AC works fine too. Thermostat works good, shows correct temperature of engine as it heats up. Coolant was quite low (also another issue I'm dealing with trying to track a slow coolant leak), but even after it was filled up there is still absolutely zero heat coming through.
Any advice, hints, tips? Trying to see if this is something I can track down and deal with or best suited for a professional.

Thank you

 

 

Yes I can hear compressor turn on and off.
Both fans are running
I believe the blower turns on as it's pushing out lots of air
Not sure about the mix door. need to look this up as I dont even know what it is

Just tried it again and I noticed warm air coming out of the right side and cold air out of the left. The air out of the right still isn't as warm as it should be. Gonna try and see if anyone else had this issue on here too.

 

 

My TSX had this issue with heat being hit or miss last winter. Turned out to be the hose on the radiator overflow reservoir was sucking in air and there was an air pocket in the cabin heat exchanger. New hose, purging the system of air, and topping off the antifreeze solved the problem at the dealership. I thought it was heat/AC mix door systems going out since the vehicle had +150,000 miles. I would check the overflow hose, radiator cap, low antifreeze and color of engine oil, and any leaks around the engine bay to make sure they are 100%. I had a 97 Honda Accord with +100K miles and I had a bad radiator cap that was slowly leaking fluid when it got to operating temp. Only noticed because of the dry crusty antifreeze residue around the cap.

Low antifreeze and milky engine oil is a bad sign. Your head gasket is bad and mixing with the engine oil if you see that.

 

Slow coolant leak-check your engine oil for a milky look, you might have the dreaded trans cooler/radiator leak going on.

 

Yup it is definitely the mix door. Found where it is located and after switching the heat from cold to hot and prying at it with a screw driver I seen it gets stuck half way up towards the heat setting.
Going in to acura what is this part actually called? Im guessing it is some kind of actuator? will they know what im talking about if i say mix door?

 

 

I had the same problem on my previous 99 TL. Got a new one put in and all was good again.

 

I think I'm having this same issue. 2007 RDX. Do you have to remove the gas pedal to get one of the screws out that's holding the actuator? I only see two screws and I can only get one out because the gas pedal is in the way. Blower works fine. AC works great. I hear the compressor and fans. I'm just annoyed!!

 

I hope this helps you with your install 🙂.

You might need this part information ℹ️.

You might also need this parts information ℹ️.

 

You are the man!!! Never heard of the heater blend door actuator before. Looked at it, disconnected the green plastic piece with wiring that goes into it...plugged it back in and BOOM the heat started working immediately. Thank you so much!!

 

Big problem on the RDX's. Mine made noise but worked fine. My service advisor heard it and ordered one for us, it was only like $30,I think, it wasn't much.

 

Rather have an easy fix like this over major issues with the compressor

 

Thanks for sharing this thread. I am hardly on here unless there is an issue. I was able to do a power reset on my Motor Mix Door and its working now! It makes a lot of noise adjusting but its working. Love quick fixes like these. If it does this again, I guess I'll just order a mix door motor from RockAuto.

 

Same issue but the fans aren't running. What would the issue be then?

 

I wonder if its the same for us. We have ours set at 23C and it doesn't feel very warm (2012 tech). For example, our 2007 rav4 it too is set at 23 and it gets hot in the vehicle. On the RDX it never feels hot (warmish ok, but not hot) also my hands get cold. Yes I can wear and do sometimes wear my leather gloves but I prefer no gloves. No leaks anywhere and not low on any fluids. I'm thinking it might be the heater blend door or perhaps a bad relay switch.

 

FWIW, after experiencing mech lockup in a couple of unrelated applications I now try to regularly cycle things like this through their whole range of motion every so often. Mirror adjusters and these blend doors fall into this class of product- on/around the first of every month move them to extremes then back to where you like them.

 

Glad, I was able to help you fix it very simply and for free.

Check the blower fan to see if it’s working well. It’s located behind the glove box. If not it may need a new heater core.

 

CSMONEY for the win again I bet.

Same deal we got the tropical storm deal and it cooled down some too. Windshield fogged up so bad from the humidity that I was gonna use some heat to cook it off, no heat.

I am also going to bet my *** that it's failed because the intermittent leak I have getting my driver floorboard wet is making its way across this part on it's way to my floorboard.

Cannot figure out where it is leaking to save my life! Any ideas? Sometimes I think it is that the windshield comes unsealed and reseals? Grrr...

 

check moonroof drains and driver door seals, and windshield area near hood/wipers.

 

Thank you. I checked the roof drains with bottles of soapy water. Those apparently go down come out by front wheel wells.

What am I looking for around the hood/wiper area?

 

 

There is no heat on both drive and passenger sides. The coolant was extremely low. I filled it up but the heat did not come on. The blower works as the AC works well and when on heat, it blows cold air.

From the threads I read, it sounds like it could be the mix door/actuator. I'll check if the cable is sticking as one person mentioned.

Is there one on each side, and since there is not heat on either side, are both bad. It sounds to me like something else is causing both sides to not put out heat. Please advise.

 

My driver's side actuator would sometimes stick since I would go roughly 8-9 months without using it (Phoenix resident). Each time it did, I was able to just give it a smack and it would work fine for the rest of the winter. I recommend inspecting it first - it's right there above and to the right of the gas pedal. You can give it a tap with a rubber mallet and also unplug it and check the harness to make sure it's secure. Replacing it is a bit tougher, but very do-able.

 

That actuator pulls and pushes the heater control valve ..I’ve replaced my son’s first and mine after one chilly drive home with the bride .
Too the OP ,check out Rockauto…