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heater blowing hot constantly

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2.4types2003

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Location
Manchester
Car
Honda accord
I have a Honda accord 2.4 type s 2003. i have had the car stood for nearly 6 months due to doing substantial work due to it being fully submerged in the winter floods in my local area. the car is all working and everything is in tact due to replacing all of the main components to the car. sadly however when running the car today after doing some work it was taken out for a drive to stretch its legs only to find that the heater when turned on the low setting for cool air it happened to be blowing out hot air consistently and not once did it change. just to take into account the fans on the car are in full working order and the engine didn't overheat at all it kept below 90 and the fans kicked in providing the engine to cool however in the inside of the car it blown out red hot air only and I wanted to know if anyone can relate or knows of what the true nature of the issue is. the head unit of the car has been replaced with a fully operational one which was the same model as the one in the car at the time of the floods so i think that can be ruled out ive not tried the fuses yet and was interested if it could simply be a blown fuse as these to Haven't been replaced yet i do need to know as soon as possible as i go away in less than a week on a long journey in this car and need to solve the problem as quickly as possible thanks.
 
Which side is not working the mixer is not working most likely damaged due to water damage one on each side of car

Sent from my SM-G901F using Tapatalk
 
I think he needs to check if the A/C itself is working first, which is in the DIY in the link - check of compressor clutch and relay, and more descriptions of system throughout, right to the end
 
i had similar in mine, passenger side was fine, drivers only blew hot what ever it was set to.
the dealer diagnosed the motorised flap that diverts hot and cold air, but luckily it all started working again before i needed to do anything.

i guess something got stuck, and then freed itself
 
^ but your car wasn't submerged in water up to the top of the front wheel arch
 
the air conditioning doesn't work. when pressed it causes the car to judder and a loud grinding noise to come from the air conditioning unit so i ***ume that this is broken. however does this explain why the car is blowing got constantly as I didn't think that it had anything to do with the general controls of the car. when it is set on low it still blows hot air out and when put on high it then blows out even hotter this is literally the only thing left on the car to then complete and i go away in less than a week and need it ready. is there a list of fuses and relays as well as locations as to where parts on the car for the heater system is so i can distinguish the true cause to the issue thanks.
 
could you if possible send me a list of things to check before actually replacing any parts and also after the list of things to check could you show me a list of all the components that work the heater and if possible the locations so i can speed up the process it would be amazing if you could do that thank you :)
 
2.4types2003 said:
the air conditioning doesn't work. when pressed it causes the car to judder and a loud grinding noise to come from the air conditioning unit so i ***ume that this is broken. however does this explain why the car is blowing got constantly as I didn't think that it had anything to do with the general controls of the car. when it is set on low it still blows hot air out and when put on high it then blows out even hotter this is literally the only thing left on the car to then complete and i go away in less than a week and need it ready. is there a list of fuses and relays as well as locations as to where parts on the car for the heater system is so i can distinguish the true cause to the issue thanks.
Click to expand...
well there are two things involved in the air-conditioning
1. a cold source - this is the compressor (which is driven by the auxiliary belt), the condenser (aka aircon radiator, in front of the engine radiator)), the evaporator (which is in the heater core, and is the actual cold source), and the refrigerant (which is in the piping, compressed by the compressor, and expanded in the evaporator).

2. a hot source - this is the "heater matrix" (which is in the heater core)

Both of these are used during control of the temperature in the passenger compartment, each source is either on or off

With the A/C set to OFF the compressor will not run, so there is no cold source
With the A/C set to ON (or AUTO), the compressor will run, and this is probably the "loud grinding noise"

With the target temperature set to LO the heater matrix should be OFF, at most other target temperature settings the heater matrix will be ON.

2.4types2003 said:
could you if possible send me a list of things to check before actually replacing any parts and also after the list of things to check could you show me a list of all the components that work the heater and if possible the locations so i can speed up the process it would be amazing if you could do that thank you :)
Click to expand...
Easiest thing to check is the operation of the heater matrix.

With target temperature set to HI the valve should be as in the picture below (it's on the bulkhead at the back of the engine)

IMAG0555__zps0f8598e7.jpg




With target temperature set to LO the valve should be as in the picture below

IMAG0556__zpsffadb3f7.jpg



If that valve does not shut, that is one of the problems.


Next you need to check the operation of the A/C

I'm ***uming that the "loud grinding noise" is the compressor, and if it really is making a "loud grinding noise" then I suspect that the compressor is knackered.


IIRC your car does not have built-in satnav so the A/C controls are manual buttons.

With Auto ON, does the "loud grinding noise" go off when you turn the A/C OFF using the A/C button, and does the "loud grinding noise" come back on when you turn the A/C ON using the A/C button ?

If yes, then the compressor is being turned on and off by the system, so next thing is to check if the A/C is working properly. There are two typical reasons why the evaporator is not behaving as a "cold source"

A. low refrigerant pressure
B. perished consenser

Since the engine compartment was submerged in water, it's possible that the condenser is clogged or perished. You can visually check the condition of the condenser, read this http://typeaccord.co.uk/forum/topic/21792-air-con/?p=230334 and this http://typeaccord.co.uk/forum/topic/21792-air-con/?p=230348

If the condenser looks ok, then the system may have lost some of the gas, and/or the compressor is knackered.

There is also a built-in diagnostic, read this http://typeaccord.co.uk/forum/topic/21770-blowing-hot-and-cold-air/?p=230336

Using that diagnostic you can check the state of all the sensors involved in the operation of the A/C system. If all the sensors work ok and sensor 5 (evaporator temperature) is not cold, then either the refrigerant needs re-gassing, or the condenser is perished, or the compressor is knackered.

edit: just one other thing to check, has the pollen filter been replaced (as that would have been submerged in water) ?
 
the heater thing you shown in te images could be the source of the problem as mine hastnt closed which could be why the car is consistently hot and so i think this could be seized the only thing is i dont know where it goes from that point in the car i will spray putting some maintenance spray on it to see if the cable will move in any way. secondly i think i need to put a new air conditioning unit on the car as it simply is knackered but i can live without that for a few weeks just have to keep it off.
 
when pressing the auto button i hear a click or clunk that tells me that something is trying to engage the air conditioning system however then the loud grinding noise becomes a part and sends the car into a judder so i think its best not to use it and leave it off but i do want to get the car to blow some cool air into the car as at this stage i couldn't go 6 hours with that heat in my face. in relation to that pully thing on heat matrix it doesn't move and never moved from me changing the car controls to hi or low and so by that not moving i suspect this is the problem.
 
2.4types2003 said:
the heater thing you shown in te images could be the source of the problem as mine hastnt closed which could be why the car is consistently hot and so i think this could be seized the only thing is i dont know where it goes from that point in the car i will spray putting some maintenance spray on it to see if the cable will move in any way. secondly i think i need to put a new air conditioning unit on the car as it simply is knackered but i can live without that for a few weeks just have to keep it off.
Click to expand...

The valve cannot be moved with the cable attached so don't try to move it with the cable attached (at the other end, the cable is probably attached to either a small high-geared motor, or a worm-drive).

But it is easy to detach the cable from the valve. In the picture, the clip over the blue cable is very easy to pull away. Just get your index finger behind the tab on the bottom left (in the picture) then pull it sideways and the clip comes up, and the blue cable is no longer captive. Then the cable can be moved outwards a bit, and the metal loop pulled off the pillar on the valve. With the cable off the valve, the valve can be moved very very easily.

If you can move the valve by hand (with the cable detached), now test the motor that moves the cable. Turn the ignition on (you don't need the engine running) set the aircon to OFF, fan speed as low as possible, and then
1. if the cable is retracted (for valve in the OFF position) put the temperature to HI, and you will hear the motor extend the cable
2. if the cable is extended (for valve in the ON position) put the temperature to LO,and you will hear the motor retract the cable

So there you have it, how to test the valve and the drive separately.
1. If the drive can be heard and the cable moves, but the valve is stiff, the valve is the problem
2. if the valve moves easily and the drive is silent (with cable not moving), the drive is dead
3. If the valve moves easily and the drive can be heard, but the cable doesn't move, then the cable has come adrift from the drive



2.4types2003 said:
when pressing the auto button i hear a click or clunk that tells me that something is trying to engage the air conditioning system however then the loud grinding noise becomes a part and sends the car into a judder so i think its best not to use it and leave it off but i do want to get the car to blow some cool air into the car as at this stage i couldn't go 6 hours with that heat in my face. in relation to that pully thing on heat matrix it doesn't move and never moved from me changing the car controls to hi or low and so by that not moving i suspect this is the problem.
Click to expand...
The compressor (aka refrigerant pump) is right down at the bottom on the auxiliary belt, and obviously its pulley runs all the time. but there is an electrically operated clutch to engage the pulley so that it drives the compressor. The clutch is operated when the A/C is turned on. The clunk is the clutch engaging, and the loud grinding noise is probably the compressor, which is probably knackered from being immersed in water. To get the A/C working, if the compressor is the loud noise, you will need to check out that compressor before anything else.

If I were you I'd still check that aircon diagnostic, it is very simple to use. If the electrically operated flaps (behind the dash) are stuck then forget the A/C because as well as fixing the compressor, you will have to remove the entire dash to get to everything. Here is the link to the aircon diagnostic again http://typeaccord.co.uk/forum/topic/21770-blowing-hot-and-cold-air/?p=230336
The first 7 "sensors" all need to work.
 
we had the car running today. we have got the air conditioning working now and it no longer makes a grinding noise in fact its all back to normal. the only thing is i've had to manually push the cable which enabled cool air to flow through. the AC also works perfectly feels like a fridge when it gets going lol. what is the silver box thing that the cable runs into called so i can find a replacement part as i presume this is not pulling the cable open or closed and so not changing the temperature of the car ??
 
so what was making the grinding noise, I'm intrigued ??

I presume that the "silver box thing" is something you can see tucked down in the dash, which I think is a metal duct that I've seen in the Honda ESM (electronic service manual or DVD). The cable runs down behind that dt and into a drive unit that, believe it or not, they call "Power Transistor" :blink:

It's #11 in this link, cable is #12
https://www.lingshondaparts.com/honda_car_parts_selection.php?block_01=17SED01&block_02=B__1721&block_03=529&block_05=hcr

I think you can get to it by removing the pollen filter and the blower motor
 
The acc motor thing was the thing making the grinding noise but once it was pressed and the engine was revved over time the noise went and the air conditioning now works fine. In regards to the silver box I it is under the bonnet and the cable that you said opens and closed is attached to a silver box to the left of it and I wondered what it is as it mustn't be pulling the cable open or closed causing the heater to blow hot constantly. I manually moved the cable so the car is on cool air all the time so it's drivable but I do want it sorting :)
 
I have no idea what it is and I ***ume it must be the problem as the cable is not moving from hot to cool air when the temperature controls are changed and when manually pushing the cable it goes from got to cool so it must be this silver box
 
2.4types2003 said:
The acc motor thing was the thing making the grinding noise but once it was pressed and the engine was revved over time the noise went and the air conditioning now works fine. In regards to the silver box I it is under the bonnet and the cable that you said opens and closed is attached to a silver box to the left of it and I wondered what it is as it mustn't be pulling the cable open or closed causing the heater to blow hot constantly. I manually moved the cable so the car is on cool air all the time so it's drivable but I do want it sorting :)
Click to expand...
I think you mean the compressor, I guess you mean you thwacked the pulley which meant that the electric clutch pulled in, I can only ***ume that the "grinding noise" was the electric clutch slipping. If so, with it having been immersed in water, it might happen again.
2.4types2003 said:





This is the image of the box the cable runs into
Click to expand...

The cable doesn't go into that, if you run your hand along the blue cable, the cable disappears through a small hole in the bulkhead.
That "box" is the clutch master cylinder LOL There is a small white reservoir above it at the top of the bulkhead with a rubber tube that feeds into the back of the clutch master cylinder. When you put your foot on the clutch, it forces fluid out of a metal pipe at the front top of the master cylinder.(you can see the union in the picture)


2.4types2003 said:
I have no idea what it is and I ***ume it must be the problem as the cable is not moving from hot to cool air when the temperature controls are changed and when manually pushing the cable it goes from got to cool so it must be this silver box
Click to expand...
The cable is moved by an electric drive on the other side of the bulkhead, either that drive or the cable itself might be seized from being immersed in water. If you turn the ignition on (don't start the engine), set the aircon to OFF, fan speed as low as possible, you should be able to hear the electric drive on the cable when you set the target temperature to LO, and then up to HI, and then back to LO. Try it with an ***istant watching the wire coming out of the end of the blue cable, to see if the wire is moving, or the blue cable itself is moving. You shouldn't be able to move that blue cable at all, the wire inside the blue cable is the part that should move the valve (when the electric drive behind the dash retracts or extends the wire).
 
okay i will try this today and let you know as you can see i know absolutly nothing about cars and parts hahahah ill inform you of the results later thankyou :)
 
we have tried watching to see if the cable opens or closes and it doesn't do anything a tall it just stays open all of the time and that what makes me wonder what the problem could be. what is this motor you speak of behind the dash in which could be broke and where is it located so i can pull it out as i suspect that it is this that is the problem ?
 
2.4types2003 said:
we have tried watching to see if the cable opens or closes and it doesn't do anything a tall it just stays open all of the time and that what makes me wonder what the problem could be. what is this motor you speak of behind the dash in which could be broke and where is it located so i can pull it out as i suspect that it is this that is the problem ?
Click to expand...

It's #11 in this link
https://www.lingshondaparts.com/honda_car_parts_selection.php?block_01=17SED01&block_02=B__1721&block_03=529&block_05=hcr

There's not much in the Honda ESM (service manual on DVD) on how to get to it, but the ESM shows a sketch of the mechanism that is inside the dash.

You might have to remove the heater blower to get to it (the pollen filter sits inside the heater blower unit).

I'll take a look myself
 
Right, it's NOT #11 ("power transistor") in the link https://www.lingshondaparts.com/honda_car_parts_selection.php?block_01=17SED01&block_02=B__1721&block_03=529&block_05=hcr

#11 "power transistor" is for the heater blower :eek:

The hole in the bulkhead where the blue cable goes, is slightly on the driver's side, so it will not come out anywhere near the heater blower anyway (which is on the passenger side behind the glove box).

I've had a look under the dashboard upper panel (which holds the target temperature display and comes out very easily) and it's not in there.

So the drive for the blue cable must be behind the instrument panel, or down

This sketch shows the LHD car, the RHD wil be symmetrical.
The cable drive unit is located top left in the sketch (so it will be behind the instrument panel)

SEA3E50G10500000000DAAT02_grabbit.jpg
 
i replaced the motor to which the cable attaches and it is now all working perfectly. i paid £20 for the part from a scrapper, and its now all functioning perfectly. i want to thank you for all your time on this topic in finding the nature of the topic. the fault P2A00 O2 SENSOR CIRCUIT RANGE/ PERFORMANCE BANK 1 SENSOR 1 and wanted to know specifically what this is as it is off now and didn't come back on a tall once clearing and replacing the motor thing on the cable it came off.
 
P2A00 is similar to P0135 (in the other thread http://typeaccord.co.uk/forum/topic/21907-engine-management-light-on-and-wont-go-off/ ) in that they both relate A/F sensor 1.

DTC P2A00 indicates A/F Sensor (Sensor 1) Range/Performance Problem , which might have been due to the missing fuse, or it might be poor connections or loose terminals, or it might be a dodgy A/F sensor (as mentioned in the P0135 thread, some aftermarket sensors can be problematic).


Right, I have two intriguing questions for you to answer LOL
  1. how did you get to the motor which the blue cable attaches to ?
  2. how did you get to the IMOES unit that you replaced some time back ?
 
I got my dad to do it with the cable he just started by removing the old one which was held on by 4 screws then began to slot it in and manipulating it back into the box and it worked. In regards to the imoes I replaced it as I bought it with the immobiliser key and ecu and it's a little box with a green end that us under the dash near the glove box
 
I think it could well be a air flow sensor throwing the light on but it's only when the car gets to temperature that it comes on
 
2.4types2003 said:
I got my dad to do it with the cable he just started by removing the old one which was held on by 4 screws then began to slot it in and manipulating it back into the box and it worked. In regards to the imoes I replaced it as I bought it with the immobiliser key and ecu and it's a little box with a green end that us under the dash near the glove box
Click to expand...
yeah I just wondered how to get to each of them, the Honda ESM (DVD) shows sketches of what they look like but doesn't tell you how to get to them, and the only way is to guess where they are and then find a description in the ESM on how to remove the panel that you think is the right panel to remove :rolleyes:


2.4types2003 said:
I think it could well be a air flow sensor throwing the light on but it's only when the car gets to temperature that it comes on
Click to expand...
if it keeps coming on you might have to get another one, but bear in mind what some people said in the other thread about aftermarket O2 sensors
 
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