Rear Window Heater

[Capriscott]

Hi all, i am trying to get my rear heater working.

I have tested my relay and all works fine.

When I press my switch nothing seems to happen and the relay does not click in and out.

Any ideas from the relay as to where the wires go? and where they should join?

Thanks

[Major_Tom]

Hi all, i am trying to get my rear heater working.

I have tested my relay and all works fine.

When I press my switch nothing seems to happen and the relay does not click in and out.

Any ideas from the relay as to where the wires go? and where they should join?

Thanks

So you tested the relay off the car and it clicks right? But with it installed, it does not?

[Capriscott]

Yes the relay works fine and I have 12v on the brown/yellow wire. I'm guessing the black/red is the negative but I am struggling to find where that goes. The other two wires are the heavies for the heater itself.

Am I correct that the black/red wire is the negative?

[Bug]

I'm going to assume you have already checked the fuse?
Have you tried popping the switch out, unplugging it and simply putting a wire across the two sockets on the plug?
If this works it's a simple switch change.

[Capriscott]

The fuse is all good. I have temporarily put in different switch which I know works.

Guess I'm just asking if anyone has an accurate wiring diagram of this system.

[D366Y]

I've found this website very helpful for wiring diagrams

http://www.a400mod.com/Fuses.htm

[Mc Tool]

How did you test the relay? Dont assume that because it clicks its ok ,if the contacts are fried it will click but not actually flow any juice to the heater. So ya have to test them under load ( volt drop test is easiest ). My heater is knackered , only about half the horizontal strands are intact ,. This is significant as if your used to testing the resistance or current flowing thru an element its usually all or nothing ,however each strand in a screen heater element is effectivley a resistance in parallal ,when some strands break it changes resistance and current flow ( I dont want to get into calculating resistances in parallal now ). I guess Im saying that if you get weird readings on your meter its probly just a half puckerood element

[Allan mcl]

Where abouts is the hew relay located and how do you test it.when I press the switch I can hear a click but the light does not come on,I have renewed the bulb and replaced the switch any ideas.
Cheers Allan.

[Mc Tool]

Its up under the right hand side of the dash,further forward of the bonnet release ,on the inside of the inner guard. Gotta watch too coz some relays have the same pin pattern but are wired different inside and cannot be used , this tripped me up while I was sussin my heater operation ,I think there is also a relay for the rear fog lights. Someone wired my fogs to work as extra brake lights , probly coz our fog lamps are usually on the front and I think our rule makers decided you cant have extra bright tail lamp as peeps would confuse them as brake lights, just what harm that could do I dont know.

[Allan mcl]

Thanks for that, checked relay all was fine,found the problem with the wire that feeds the light connection had broken inside the bullet connection.

[Mc Tool]

Result

[Capriscott]

Sorry this is late but what I didn't realise is that it is negatively switched. So the the brown and the brown/yellow sends a negative feed to the coil of the relay.

The heater now works and all is good. Thanks everyone for your input