V70 Air Con: Evaporator Temp Sensor Location ?

[R3dbvll]

Originally Posted by timh30

The multimeter was just to confirm if the original sensor was bad, but you said the garage have now confirmed this ?

Ah right. Yes they confirm it was bad, and was given the wrong reading.

[timh30]

Hi - sorry for delay. I've still not had chance to take photos, so I've copied some from the web to illustrate the steps.

1. Disconnect the car battery, see instructions in attached image.
2. Remove the climate control unit, see this link for instructions http://www.jcrdevelopments.com/node/259
3. Unplug all the connectors to the back of the climate control unit
4. Remove the piece of trim in the drivers footwell, see attached picture
5. if you look up behind this piece of trim you should see the white plastic of the evaporator housing
6. Using your soldering iron, melt a hole in this white plastic at the location in the attached picture (from the markings on the plastic you should be able to copy the location accurately), make the hole size just big enough to insert the 'probe' end of the IAT sensor (it should click in place). use a knife to trim the surface.
7. cut 2 pieces of wire long enough to run from this hole to the back of the climate unit (30-40cm?)
8. Solder one end of each piece of wire to the pins on the IAT sensor (or find a suitable connector and solder to the wires from the connector - I used an old sound card cable)
9. Push the sensor into the hole - mine clipped into place without any glue, but if the whole is too large, you may need a bit of glue to hold in place.
10. Run the 2 wires through to the back of the climate unit.
11. Identify the connector with the brown and purple wires, on the appropriate connector (see image). Double check this is the correct connector and wires before cutting! **
12. Cut the wires at the connector (leave 4-5cm from the connector itself), then solder to the wires from the new IAT sensor (it shouldnt matter which way round they are). If you have heat shrink use this, or just use insulating tape.
13. Plug the connectors back into the Climate unit, reconnect the battery and test your climate control. Hopefully the compressor pipes will no longer freeze over and you'll hear the compressor clicking on and off.
14. If all is ok, put the climate unit back in place and the piece of trim.


** I'm assuming your colour coding is the same - not sure what year your car is.

[R3dbvll]

Originally Posted by timh30

Hi - sorry for delay. I've still not had chance to take photos, so I've copied some from the web to illustrate the steps.

1. Disconnect the car battery, see instructions in attached image.
2. Remove the climate control unit, see this link for instructions http://www.jcrdevelopments.com/node/259
3. Unplug all the connectors to the back of the climate control unit
4. Remove the piece of trim in the drivers footwell, see attached picture
5. if you look up behind this piece of trim you should see the white plastic of the evaporator housing
6. Using your soldering iron, melt a hole in this white plastic at the location in the attached picture (from the markings on the plastic you should be able to copy the location accurately), make the hole size just big enough to insert the 'probe' end of the IAT sensor (it should click in place). use a knife to trim the surface.
7. cut 2 pieces of wire long enough to run from this hole to the back of the climate unit (30-40cm?)
8. Solder one end of each piece of wire to the pins on the IAT sensor (or find a suitable connector and solder to the wires from the connector - I used an old sound card cable)
9. Push the sensor into the hole - mine clipped into place without any glue, but if the whole is too large, you may need a bit of glue to hold in place.
10. Run the 2 wires through to the back of the climate unit.
11. Identify the connector with the brown and purple wires, on the appropriate connector (see image). Double check this is the correct connector and wires before cutting! **
12. Cut the wires at the connector (leave 4-5cm from the connector itself), then solder to the wires from the new IAT sensor (it shouldnt matter which way round they are). If you have heat shrink use this, or just use insulating tape.
13. Plug the connectors back into the Climate unit, reconnect the battery and test your climate control. Hopefully the compressor pipes will no longer freeze over and you'll hear the compressor clicking on and off.
14. If all is ok, put the climate unit back in place and the piece of trim.


** I'm assuming your colour coding is the same - not sure what year your car is.

Thanks so much for this - I really appreciate it. The first chance I'll have to take a look is this weekend. I'll let you know how I get on.

EDIT : forgot to say, my car is a 2002 (52 plate).

[timh30]

Hopefully as its an 52 it should be the same as my 2001 model.

By the way, when disconnecting the battery you only need to remove the black negative lead.

[R3dbvll]

Originally Posted by timh30

Hopefully as its an 52 it should be the same as my 2001 model.

By the way, when disconnecting the battery you only need to remove the black negative lead.

I'm pretty sure it is the same. Any pointers on the process of disconnecting the battery? I've read all sorts of scare stories on this. Should the ignition be off for a period of time before disconnection for example? And what about reconnection?

EDIT : Forget what I said about the battery, the picture you included gives the relevant instructions!

[R3dbvll]

Hi timh30

I have a very bad feeling that the 2002 design is not the same as the 2001
design.

I got the AC control unit out ok, and removed the piece of trim in the drivers foot well, only to find that nothing looked like the photos you posted. All I see are black plastic pipes (for the air I assume), and no sign of any white thing that might be an evaporator.

Looks like I can't upload any images so I put them here:

https://picasaweb.google.com/1036097...eat=directlink

Thanks (in hope!)

[R3dbvll]

OK I realised that there was probably more to this that I initially thought. I had to remove another panel, that sits over the pedals. When I did that, I found what looks to be the evaporator casing.

It looks a bit different to your pictures Tim, but I think I know why - my car is an automatic, and yours is a manual.

I took a few more photos of the view of the evap. Tim, could you take a look and confirm that the white box there is the same evap casing you are talking about, and sticking a hole anywhere in there would do the job?

https://picasaweb.google.com/1036097...eat=directlink

Many thanks!

Originally Posted by R3dbvll

Hi timh30

I have a very bad feeling that the 2002 design is not the same as the 2001
design.

I got the AC control unit out ok, and removed the piece of trim in the drivers foot well, only to find that nothing looked like the photos you posted. All I see are black plastic pipes (for the air I assume), and no sign of any white thing that might be an evaporator.

Looks like I can't upload any images so I put them here:

https://picasaweb.google.com/1036097...eat=directlink

Thanks (in hope!)

[timh30]

Hi - yes that white plastic is the evaporator housing. Obviously on my pictures the clutch pedal is partially in the way. If you reference the bit of plastic that protrudes at the bottom with the join part of the way up (on my picture as well) you should be able to create the hole in the same place.

I've edited one of your pictures to show where you want the hole.

[R3dbvll]

Originally Posted by timh30

Hi - yes that white plastic is the evaporator housing. Obviously on my pictures the clutch pedal is partially in the way. If you reference the bit of plastic that protrudes at the bottom with the join part of the way up (on my picture as well) you should be able to create the hole in the same place.

I've edited one of your pictures to show where you want the hole.

Thanks for that! Took me a little while to figure out why your pictures were different to mine - yours has a clutch pedal in it!

I'll have a go at completing this tomorrow, and report back....

[timh30]

Any luck with fixing the A/C ?