Aircon only works when lights turned on?Solved Pics

[MacFamily]

Well we havent used the A/C cause it needs regasing, so today when I was cleaning the mud from in and out of the car.I gave the radiator a good clean and the condensor, and when I was done I thought I might give the thermo fan a test.

Well it didnt work and after a little playing around found out that when I turned the lights on with the A/C fan swithched to either 1,2, or 3 it started to work with air blowing out the vents.

Now the car had a little work done to it not long ago with rust cut out ect behind the A/C so the whole lot was pulled out but I rewired everything and it was working perfectly when I got it back on the road besides having no gas.

So ive checked all wires, fuses relays but it has me stumped why it would only work when the lights are turned on.The only thing I can think of is the power for the A/C is touching the power wire for the lights and only working when lights turned on.

Unless there is a earthing problem, but anyway i have half the dash out and batteries out checking all wires.Thought that maybe somebody had another idea I hadn't thought of.

Anyway I will continue to check more wires tomorrow, but I cannot see how the lights and A/C can cross paths.Ive also checked wires under bonnet with no answer.I may also pull fuse box from firewall and check behind that.

[MacFamily]

Well I did a search before posting this but I could not find anything but I didn't look hard enouph.Well I had a look in the Good Oil section and found a post that Ron(p38arover) had of the A/C wiring diagram thanks Ron.

Also after reading Ryans(Ranga) post about his A/C and cig socket not working I put two and two together.

When I put the dash back in I must Ive tested the A/C with lights on and thought everything was OK.Anyway I had connected the white Ignition Pickup wire to the power for the light on the cig socket and not the power for the socket green wire. Pics below to explain

You can see the Ignition pickup wire connect to the power (red) for the light


Ignition pickup connected to the Green wire power for socket

[p38arover]

Glad the diagram was useful.

Who'd have thought that the aircon mob would pick up power from there. What if you'd decided to wire the cigarette lighter socket to a permanent 12v feed rather than ignition switched?

[VladTepes]

.. which s exactly what iw ant to do - rewire my cig lighter plug to have constant connection to battery / not switched. So now I have to find somewhere else to take the pwoer pickup for teh a/c from.. apparently. ??

[MacFamily]

Glad the diagram was useful.

Who'd have thought that the aircon mob would pick up power from there. What if you'd decided to wire the cigarette lighter socket to a permanent 12v feed rather than ignition switched?

Never thought about that but Iam sure you could rewire it to either the stero, rear wiper or pull the wire down to the fuse box and rewire it to another fuse.

But yeah I thought they would use another souce of power when installing the A/C but there you go Ive learned something this week and yet again AULRO has helped and saved me money.

Would hate to see the bill from and auto elec to fix that simple problem.

[Stringy]

can u put up a link to this wiring diagram please? my air con was once working ut all of a sudden my interior light and aircon just stoped....i rewired the interior light and installed new ones but still cant trace the fault for the a/c....ownin a defender is good practice for an apprent electrian i can tell u hahaha

[MacFamily]

can u put up a link to this wiring diagram please? my air con was once working ut all of a sudden my interior light and aircon just stoped....i rewired the interior light and installed new ones but still cant trace the fault for the a/c....ownin a defender is good practice for an apprent electrian i can tell u hahaha

Here you go Stringy 4th post down Fuse box under passengers seat on Defender 300TDi

[Stringy]

thanks mate....ill dig in and have a look....cheers

[Stringy]

traced fault to the exact same as macfamilies