Interior Heating...or Still Lack Of...

[GT4THUG]

hi, i have taken the rear speed resistor pack out and place in front, and no operation

 

have put 12v across the fan, it works

 

use the digital controls to get heat in / out and nothing but cold (ish) air comes in

 

the ambient temp sensor shows from 7 deg to 39 deg depending on teh timeof day but nothing else changes

 

i have little or no air flow thru the vents to which i was told try another control unit, to which today i have one from a breakers and still the same...

 

the setup still will not fire the blower up, as far as i can see all the fuses (drivers side main box i presume are ok)

but theres mention of a relay to the fan where is it located and what pins can i bridge to give full power to check if the relay has failed OR have i missed another fuse or setup as well??

 

haynes is as much use as nowt as not making any sense on the diagrams and the CD i tried to D/L wont ...

 

so i have 2 blowers that wont operate but the fans will rotate on full with 12 volts going thru them, little air flow thru vents and cant hear operation when i press buttons, no heat coming thru but pipes are hot front and back, and it is not a diesel its a petrol 2.3 Ghia X with climate control but nothing is working to fire up the heat, even if i had just full speed it would be a joy in the mornings...

 

so any ideas as this on e really has stumped me now... god knows why they made the simplest of things so complicated!

 

cheers guys

[chrispb123456]

relays show as being inside ATC module

[GT4THUG]

relays show as being inside ATC module

 

 

trawling thru the archives i find a 114 relay mentioned hidden behind the fuse box, before i start to look how to remove to see and check is there such a relay on this model chris do you know ? as its beginning to get my pip now as there must really be something so simple its daft that has killed my system as everything i replace / check all seems ok

 

cheers again

[Mirez]

What year is the car? Put your car details in your signature! There are quite a few revision changes to the heating system.

[GT4THUG]

What year is the car? Put your car details in your signature! There are quite a few revision changes to the heating system.

hi, have done now sorry but just incase it not listing my sig

 

its a 96 2.3 DOHC 16V Ghia X

[Mirez]

Right then the blower is fed via a relay (K73) which is powering both the front and rear blowers.

 

Get your volt meter out and check:

 

F34 and F39 (both 25Amp) and intact (take then out of circuit to do this!)- there supply is switched by this relay and powers both the front and rear fan. They are hidden from view and will require you to drop the box slightly for access, both are in the top left corner and are the 8th and 9th in from the left.

 

Next, with ignition and climate on you have 12V on pin 3 of connector C312. Thats the RED one on the back of the climate panel and thats the trigger for the relay, you'll obviously need that plugged in whilst measuring so be sure not to short anything out!

 

Then, at the front blower - disconnect the connector and measure voltage between the Red/White pin and a ground source with the ignition and climate on. You should have 12V here if the above 2 tested ok. If thats not the case the the relay is defective, or the supply to F34 & F39 is missing. If you do have 12V here then measure resistance between ground and the Black/Red pin.

 

A resistance control unit on the ground side is how the blower speed is varied, if you showing open circuit on the black/red pin then its this thats likely to have failed.

 

Report back!

Edited May 11, 2010 by Mirez

[GT4THUG]

Cheers for that Mirez

 

thats 2morro's to do might moider the where are the locations if i cant find in the day , but apart from that thats the good old english i needed to start me back off again :lol:

[GT4THUG]

Mirez the conclusion is as follows

 

F 34 and 39 are both intact but ones a 30 ones a 25 a green sleeve and a blue are behind i can pic if u need

 

pin 3 stripped the red block and probed to get a +12v

 

blower red/white is a 0V with ign and climate on so first item to be questionable is the relay now **ahem** which one is it and roughly where is it please... as i think with this we are on a winner :-) can we jumper it to double check as can give full 12v thru and fire the fans up :-)

 

Cheers as this seems a result and a quick pop the the motor factors seems in order!

[Mirez]

Strange they are shown as both being 25A. Can you see their output colours? They are supposed to be fed from the same supply so should both be on the blue cable. F34 outputs a Red (with black tracer) cable and F35 outputs a solid red. Both are 4mm cable so substantial!

 

The relay is K73 and is described as under dash, passenger side. Which is pretty crap really but should be easyish to spot as it appears to be on its own with a black base.

 

It seems a basic relay from the wiring diagram, with one ground, one switch, two supplies and two outputs.

 

 

 

The switch Wire from the ATC panel (the red connector pin3) comes in on pin 6 so 12V should be there with everything on.

Ground is on pin 3

Supply from F34 is on pin 4

Supply from F39 is on pin 2

Output from F34 is on pin 5

Output from F39 is on pin 8

 

So theoretically you should be able to bridge pins 4 and 5 for the front fan to come on and pins 2 and 8 for the rear. You could also take the connector off and put 12V onto pin 6 and a ground on pin3 then measure continuity between the pins to prove its dead..... Once you've found it :16:

Edited May 12, 2010 by Mirez

[GT4THUG]

will have a look 2morro and look for this relay, anyone else know where it is as i am just going to drop the glove box and crick me neck looking around the inside till i can see anything :-) and will do the old celica fuel jumper mod to see if i can fire front and back fans on respectively then a replacement from somethere or look at schematic make a connector to make a std relay (2 of ) do the same one if it is silly money...at least one will stay on if a relay fails ...

 

but cheers so far for that...

[big_kev]

will have a look 2morro and look for this relay, anyone else know where it is as i am just going to drop the glove box and crick me neck looking around the inside till i can see anything

 

Personally I would look about 8 inches above the hedgehog .....pic below

 

[GT4THUG]

will have a look 2morro and look for this relay, anyone else know where it is as i am just going to drop the glove box and crick me neck looking around the inside till i can see anything

 

Personally I would look about 8 inches above the hedgehog .....pic below

 

Cheers Kev

 

going to remove the top glove box this afternoon and hopefully once this has been done the heater will be fully functional, this takes be back to the hidden fuse days of the old mini's lets put something that fails hidden in the depth of the dashboard....

[GT4THUG]

well.... bridged both outputs with wire and.... they work... have 12v thru both and the climate control will vairy the speed.

 

 

put 12v thru pins 6 and 3 the relay clicks... more than it does in the loom

 

just going to run a meter across the relay to confirm, but either the supply to pin 3 and 6 is weak / broken or relay is defunct

 

but yay i have both the heaters blowing now :-)

 

so its either a quick loom look at or a relay and all dash back and warm !

[GT4THUG]

.... the positive feed for pin 6 on the relay is 0v and thats where the problem lies on my system as once a 12v is across the pin the relay closed and fires the 2 heaters up :-) rather than keep ripping out more and more dash looking for it i have resolved the matter with a fresh feed, and ooooh a summers day and sweat box :-) .... roll on a cold day now :-)

[Willie Krashitt]

Well done! and don't forget to change your signature!

[chrispb123456]

.... the positive feed for pin 6 on the relay is 0v and thats where the problem lies on my system as once a 12v is across the pin the relay closed and fires the 2 heaters up :-) rather than keep ripping out more and more dash looking for it i have resolved the matter with a fresh feed, and ooooh a summers day and sweat box :-) .... roll on a cold day now :-)

Hi there glad to see your resolving the problem, that pin six on the relay which you say is dead on closer look at the diagram is fed from pin 3 of the red connector on the back of the control module,as Mark pointed out.

The ATC module appears to have more than one supply. F6, F14, F22, just wondered if this may affect operation of Air-Con

[Mirez]

It can't be a fuse as he had 12V on pin3 of the red connector - could only have been a loom issue if it isn't arriving at the relay. :16: