Range Rover Classic headunit headache! Pics of the wire based carnage within...

I want to replace the standard headunit in my soft dash RRC - it has the uprated (Harmon Kardon?) stereo with tweeters on the a-pillars and a sub and amp in the boot.

Anyway, bought a new headunit with an RCA output on the rear for the sub and amp.

Went to plug it in and was greeted with a mass of wires running into the original headunit! We have three block connectors - two fit perfectly into the new ISO lead, but the third (which only has 2 wires running into it?) is spare. There are the 2 RCA leads (helpfully a different size the those on the back of the new h/u), a very chunky connector, possibly for the aerial (are they called AB connectors? Lots of pins going into a plug) and then three what I assume are earth leads all trapped under a nut on the back of the h/u, the bolt that I think is often used to stabilise a unit in the dash.

So, short question - anyone know what the hell I need to do to sort this lot out? All I want is the radio/CD player working and the RCA's for the sub and amp. Here's some pics of the back of both units:

Old on the left, new on the right:


Old:


New:

Could the 2 wire connector be for steering wheel controls ? The round multi pin one looks like cd changer connector, the black connector bottom left of picture of old unit looks like a din aerial adaptor, somebody will no doubt know.

I agree with above. The round plug looks like CD cable input. Although the red and black plugs on the left look like a cross between phono and din connectors.

Can you take pictures of the mess in thedashboard?

Normally (on non remote H/u's) You have:-

1 red - live
1 yellow- remote live (sometimes these are reversed)
1 black - earth
1 blue - amp
1 blue white - aerial power
1 orange - illumination
not all headunits have all cables
then

Green and green black
white and white black
grey and grey black
purple and purple black
etc. Colours may vary. These being the speaker outputs.

With RCA you may have 2, 4 or 6 depending on stereo. and 1 aerial socket.

Has the wiring in the dash been cut and shut? or is it standard?

There are two standard ISO sockets on one cable.
1 socket carries the speaker cables
1 socket for power, remote feeeds etc.

If the cables from the new head unit are marked or there is a diagram on the H/u you can work out which cable is what from looking at that.

Thanks guys! The two ISO blocks do fit into the new h/u ISO connector fine, but it wouldn't turn on.

I will take a photo of the mass of wires behind the dash later on and post it up, hopefully we can figure it out!!

Here's the images of the mess behind the headunit - any advice would be really welcome!!

Thats not a mess, not a scotchlok or twisted together taped up wire in sight ! Didnt the H/K system have two aerial inputs hence red and black connections on left side of old unit ? Try a 12 volt test light in yellow and red connections as Khryztal posted see if any live, with it having amp and sub in the boot think you might have to do bit of rewireing to get it all working.

could be the new H.U is faulty

kds said:

Thats not a mess, not a scotchlok or twisted together taped up wire in sight ! Didnt the H/K system have two aerial inputs hence red and black connections on left side of old unit ? Try a 12 volt test light in yellow and red connections as Khryztal posted see if any live, with it having amp and sub in the boot think you might have to do bit of rewireing to get it all working.

Click to expand...

OK, here's what I think from what you guys have said and having a look last night:

- 2x ISO connectors fit into the new H/U fine
- 3rd ISO connector with just two wires could be for steering wheel controls, or perhaps the CD changer controls? I don't need this to work.
- Large black (AB?) plug in the centre of the old H/U is for the CD changer

I then have the 2x RCA leads (black and red) and three black earth wires to figure out! Also, where would the sub and amp wires be in all this, as I'd like that working ideally?

Cheers!

Hi

The red and black connector is the AM/FM aerial
The big round black plug is for the CD changer
The 3 black wires are earths
The ISO connector the does not fit in the new H/U is for the original sub amp in the boot.

The original H/U does not have Phono out, I believe that the third ISO pulg feeds the amp with a speaker output which runs at a higher voltage than a phono output.

I have not long stripped out my sub/amp and the wiring to the boot.

To get your sub working with your new H/U the easiest way would be to get a small amp and replace the original amp on the sub box.

Hope this helps

Cheers
Graeme

Thanks Graeme.

For the time being I would just like the h/u to work, the sub/amp I can worry about later. What do I need to do to get this working, as plugging the 2x ISO connector blocks in didn't seem to work? I did not take the earth leads to anything at the time, as not sure which one is which or why there are three. I figured the earth would be within the ISO block somewhere, I have never had to earth an H/U seperately before. As there is no bolt on the new H/U, where can I earth it to? Anything else I need to do to get it working?

With regards to the aerial, is one lead the AM and one FM? As most are combined I thought! Do I need an adaptor so there is a male connector going into the H/U for the FM aerial? If it makes any difference, the radio reception is pretty poor too.

Lastly, any recommendation for a suitable amp to get the sub working? Just a small 2 channel amp I guess - like this? http://www.halfords.com/webapp/wcs/..._productId_264387_langId_-1_categoryId_165526

Thanks again.

Hi

You can get an adaptor for the aerial to change it from female to male like this Halfords | Halfords Aerial Adaptor PC5-29

As for what aerial lead to use I would try the black one first and see how it goes, but not sure if there will be any differance.

For the earth wires,IIRC the three that you have are 1. for the H/U 2. for the sub amp 3. the actual earth connection.
The earthing point is down on the tunnel beneath the center console. So to earth the H/U just connect the new one the same way as the old one.

That amp would do ok it has a crossover built in so that makes it easier. I think you would have to run it with the gain turned right down though. You would also have to run RCA/Power to the amp.

Hope this helps

Graeme

Just a thought on poor radio reception, is there an aerial amp powered from H/U or ignition live.

Still can't get it working! I've removed and taped up the CD changer lead, sub/amp ISO connector and the two corresponding earths. Plugged the two remaining ISO's on and attached the earth and still nothing - very odd.

Think I'll have to bite the bullet and take it to an expert - bugger!

Have you checked the red and yellow wires with a test light yet ? Sorry if you have but not seen it mentioned.

kds said:

Have you checked the red and yellow wires with a test light yet ? Sorry if you have but not seen it mentioned.

Click to expand...

No...are they the permanent live and something else?

Ones permanent live from fuse box. the other is switched live from ignition.

OK, thanks. Well both are as they were wired up in the ISO socket, I haven't touched or changed anything so they should be OK - there's no power to the H/U at all, I thought the yellow and red wires were only an issue if it didn't save settings and things!

I spoke to a friend of mine who's brother runs a car audio place - he was asking if this was the Clarion system with the amp in the boot, I am guessing it is. He said if it was, they would need to bypass this amp and run speaker wires through the car, which is a good couple of hours work - all to get a £55 headunit working. Does this sound about right?!

To be honest, I used to be vaguely handy with car audio back in my teens but am no auto electrician as you can tell. But I am confused - if they need to run speaker wires everywhere, then what is the plug from the car into the back of the h/u for???

I've found a solution!!!

These guys: Home will take the standard headunit, refurb it including fixing the dodgy volume control and replacing all the backlight LED's because they always go apparently, AND they fit a 3.5mm jack lead for the iPod to the back of the unit with a 1m cable - brilliant news!

So, sent my h/u off in the post today, should have it back next Wednesday.

Been wondering if you got it working, fingers crossed every thing else is ok then.

I've heard about these guys before - well its Clarion themselves isn't it.
Fortunately for me they are about 10 miles away so I might go and see them.