Rear demister / aerial control box

**Alfa Patch** · 24-08-12, 20:44

Hi Guys

Could anyone take a picture of where this is in the boot? Or describe the location in great detail.

I assume mine is faulty as i have no rear screen demisting or aerial feed to the radio. I have a spare part bought through the shop on here but can't find the original. This is all the more confusing as there is no carpet in the boot of my car so it should be easy to find?

There are some snipped off wires up by the boot's interior light and maybe thats where the unit used to be? Im not sure why you would ever remove the unit even if it was bust but i have found plenty of other 'odd' decision choices in my car so far so I'm certainly not ruling it out.

Whilst we're on the subject of boot space does anyone have a carpet set? Massive longshot i know but if not pictures would be very helpful so i can try to recreate my own as accurately as possible.

Thanks

Patch

**alfa155chris** · 24-08-12, 22:18

Remove parcel shelf it's in the middle by boot light or under drivers side panel by back window.
Have just sorted a mates heated rear window which was the fuse box

**Alfa Patch** · 24-08-12, 22:22

Thanks Chris, I'll get back on it as soon as it stops raining

**Steve Webb** · 25-08-12, 08:22

The rear screen demister isn't part of the aerial amp though, when mine went it was because one of the tabs had come away from the rear screen.

I might have the carpet from the boot as well, I'll need to take a look in the garage for you.

**Alfa Patch** · 25-08-12, 11:18

I will check that also. I assume that involves removing the c pillar trims?

Patch

**Steve Webb** · 25-08-12, 11:51

You should be able to see the two tabs on the rear window without removing anything, one of mine had obviously vibrated and snapped off , the wire was just hanging there loose.

I'm down in the garage this afternoon, so will take a look for the boot trim for you.

**AlfaJack** · 25-08-12, 11:51

If you unscrew the parcel shelf from underneath you should be able to lift it enough to feel the wires.
To get at the properly I think the rear seat needs to come out which isn't a big job

**Suzumushi** · 25-08-12, 14:06

Originally Posted by AlfaJack

If you unscrew the parcel shelf from underneath you should be able to lift it enough to feel the wires.
To get at the properly I think the rear seat needs to come out which isn't a big job

can confim that, take out rear seats, remove shelf with speakers, and you will se grey box with antenna and heater electronics inside

when mine stopped to work, one problem was exactly the same as Steve had (noone of "electronic" glue was working, so i have to solder it to the rear window veeeeeery carefully)
and second problem was burned plug socket it this grey box... had to solder it as well. and everything started to work.

regards

ws

**Steve Webb** · 25-08-12, 19:39

Just looked in the garage and I have got the trim section for the boot floor if thats the bit you need.

Oh and I noticed I've got the aerial lead from the booster to radio if you need that as well.

**Alfa Patch** · 25-08-12, 21:19

Originally Posted by alfa155chris

Remove parcel shelf it's in the middle by boot light or under drivers side panel by back window.
Have just sorted a mates heated rear window which was the fuse box

I still can't find the little f***er. I have checked by the light, taken off the drivers side C pilar trim and nothing? Is that where you meant Chris?

Wiring running to the demisters seems to be attached and running under the rear seats then under the rear footwell carpet, fairly easy to follow as they are two larger gauge wires than everything else. I really don't fancy pulling up the carpet to find it, is there anywhere else it could be?

For the time being i will keep my fingers crossed and swap the fuse!!

Having the rear seats out certainly hasn't been a total loss as i now know why my battery drains itself over time, the boot light never turns off!!

Every cloud and all that ......

**Steve Webb** · 25-08-12, 22:31

I'll stick my head in the boot and get you a pic in the morning Pat.

**Steve Webb** · 26-08-12, 09:45

Been a while since I've been up there properly, but if I remember correctly, the aerial amp should sit on top of the metalwork that the boot light is fastened to.

**Alfa Patch** · 26-08-12, 18:34

Thats where i thought it would have been but no sign.

There are two snipped wires next to the light which probably used to go to it but shouldn't there be a thick Coax style wire as well? the unit has two connextions one the is a clip connector an the other a screw in coax cable style?

Really puzzling / irritating

**AlfaJack** · 26-08-12, 19:36

Yes, it sits on top of the frame - behind the light.

There is a round multiplug thing going in - most likely to be 12v. Then there is the aerial output (round co-ax) and 2 wires that leads to the screen connections.

**Steve Webb** · 26-08-12, 20:50

Here are a couple of pics of the co-ax cable and one of the electical connector.

**Alfa Patch** · 26-08-12, 21:14

What i have is in the picture 1. I am now even more sure that some plonker has cut it off. I might stick some spade connectors on that and connect it to the module, see what that does?

Pete who used to own my car did used to go on here but understandably doesn't anymore as he doesn't own the car!! Does anyone speak to him and might be able to find out if it ever worked in his ownership?? I don't think it was him who cut it off, all the work i know he did to the car is of a very high standard.

No idea where the coax has gone, its certainly at the radio end as its stiking out from behind the dash, let the fun of chasing wires around the interior begin!!

**AlfaJack** · 26-08-12, 21:25

Mine has a roof aerial and a rear screen one. I am not sure which one is in use though.

Is this Pete from Leicester old car? If so, he is Retro-Pete on alfa155.org
Lost track of whose went where.

**Alfa Patch** · 26-08-12, 21:32

Originally Posted by AlfaJack

Mine has a roof aerial and a rear screen one. I am not sure which one is in use though.

Is this Pete from Leicester old car? If so, he is Retro-Pete on alfa155.org
Lost track of whose went where.

Mine has no roof aerial.

It is that Pete, I'll ask him. THANKS !!

**Alfa Patch** · 26-08-12, 21:57

Fitted the controller in place as in the pic.

Couple of questions..

1. Have i got the connectors labelled correctly?

2. Which is positive and negative on each connector?

3. Does 2. ^^ matter?

4. Does the coax need to be connected for it to work?

5. Can i fry the control box if i just start blindly connecting wiring to it?

6. Why does it keep getting dark when I'm trying to fix my car

**AlfaJack** · 26-08-12, 22:46

1. Have i got the connectors labelled correctly?
That is definitely the feed to the screen

2. Which is positive and negative on each connector?
Not sure

3. Does 2. ^^ matter?
Most probably

4. Does the coax need to be connected for it to work?
The demist will work without it but radio won't. I think the signal comes from the screen connections, it is them amped up through the box and finally sent to the radio through the coax

5. Can i fry the control box if i just start blindly connecting wiring to it?
Probably - it was wired in Italy.

6. Why does it keep getting dark when I'm trying to fix my car

Annoying isn't it

**Alfa Patch** · 11-09-12, 21:16

Finally fixed this.

The wiring had indeed been cut out?

After much head scratching basically the right side of each connecter to (and then from) the control unit is for the demister function, the left is for the aerial. Mine has no aerial wiring whatsoever so I guess it has an internal aerial, doesn't matter as I dont have a stereo.

Anyway with the wiring re-instated it now works and is all back together. Driving with no rear seats was very loud, pretty much like being shot-blasted wherever I went. Different car with them back

Thanks for the help