Hello all,

Let's get to it. My climate control is completely kaput. The module display works perfectly fine, it lets me change temperature and fan speed but there is zero action from the fan nor is there any cold / hot air being emitted at all.
Another interesting note, the interior lights don't work either - this screamed F49 to me but no.

This forum has been a massive help so thanks all, I've been referring to this thread massively: https://www.jaguarforums.com/forum/x...working-99202/

I have tried:
- Every fuse that links to the climate, whilst also checking every fuse visually for assurance. All fine there.
- Disconnecting the battery for a short time then reconnecting it.
- With the interior lights being gone too I checked all them to see if one had blown and effected something else. Was worth a quick look. They're all fine too.
- Went to a breakers yard and tried one of there blower motors. Nothing.
- Replaced R4 Relay, still no action.
- After doing some research I found that my specific Jag is on 2004.25 schematics, I figured it could be the resistor in the climate control module. I read than in the newer ones that's where it is? It's certainly not near the blower motor anyhow. I replaced it completely. This has not worked either.
- I purchased a mustimeter and tested those fuses linked to the climate control. F49 and F37 have some resistance but zero power to them. The R4 relay junction has the full 12v Power going to it. An interesting not is that the plug that goes into the blower motor itself is getting about 5v, this seems odd as I expected to be 12v or zero.

It would seem to me that something between the relay and the fuse is wrong, however I'm quickly learning electrics are not my forte. I've been using the wiring diagram however I must admit at this point I'm completely lost.

It's getting cold on a morning now and with no heated windscreen driving to work has gone from being inconvenient to flat out dangerous.

Any help would be greatly appreciated.

Andy

 

The electrical diagrams are your friend here and you can get a bit more friendly with them yet!
First confirm your using the correct diagrams: they're all available here: JagRepair.com - Jaguar Repair Information Resource What Model Year is it? (Important for those trying to assist!)
Assuming you have automatic climate control - you haven't said !- use Fig 6.2, bottom left hand corner, that shows all the wiring between Relay R4, the Blower and the Module
Note the three wires going to/from the module via pins IP101-6,7 and 21.
Go to the Data Page before Fig 6.2, also called Fig 6.2 and read off what values should be on each wire. Depending on your multimeter you may or may not be able to read Pins 6 and 7, but 21 is the important one
Knowing the square with 75 in it is (you implied?) the correct 12v battery supply, you can now test every point in that sub-circuit to narrow down where the break must (surely) be

 

Hi astromorg,

Apologies, my car is an 2008 2l diesel and has the auto climate control. I thought that info would go from my profile to the post so my bad.

Thanks for your response. I appreciate the detail on the specific figures and will certainly have a look tomorrow.

Andy

 

Other fuses to check in the passenger junction fuse box....
F35
F39
F44
F45

Also check your grounding point G15AL - cross beam behind dash on left side of tunnel.
That earth is shared by interior lights and AC blower relay.

 

Update

Thanks again for the replies, after getting the help of a friend we both went through everything stated in your responses plus he a few other tests.

The summary is the switch input 1 on relay r4 is registering half a volt. So there is something wrong with the W cable from the relay to the CC module itself.

Now I'm wondering what my steps will be, am I going to have to replace that wire completely? Are there any other things I can do before I have to do that? Naturally I want avoid that arduous until absolutely necessary.

Thanks all again,

Andy

 

First of all there's only 12v on that White wire to the coil of the relay when ignition is On and the fan is On
It could be the wire but it could also be the Climate Control Module. You need to check the actual voltage output at Pin 21. Push a fine needle through the wire as it comes out of the connector and measure the voltage on it when the fan should be operating

 

I seem to recall that there can be a burnt out track occur on the automatic climate control module PCB.
Worth taking the module out to inspect as the track repair is a simple job of bridging the track.