Change Of Head Unit

[Chris_Halford]

Hi,

Could someone give me a little bit of help regarding the following:

I've just purchased a Pioneer AVH-3300BT head unit, along with the Toyota > ISO connector to go into my 2004 RAV4 XT3. Easy peasey.

However, I'm looking for a little info on a couple of the wires which aren't part of the ISO connector as follows:

Blue/White ----> System Remote Control

Yellow/Black ----> Mute

Purple/White ----> Reverse Gear Sensor

Green ----> Parking Brake

What I am wanting to know is the best way to connect these up. I'm aware that the Green one goes to the parking brake sensor so that I'm able to watch DVD whilst the car is parked and the handbrake is applied (although if this could be bypassed in someway, hmmmmm). But I've read somewhere that the wire for this switch is also up in the dash somewhere which would make the install a lot easier than pulling the trim apart to connect it. Indeed am I right in saying that there is a parking brake pin already on the back of the original head unit? If so how could I utilise this without destroying the original wiring loom (I will want to put the original head unit back in if I sell the car).

The Blue/White wire shouldn't be a problem as I've also purchased a Connects2 steering wheel interface, so that one should be sorted.

What about the Yellow/Black Mute wire? Did I also read somewhere that this is also on the back of the original head unit? Or if it isn't can I still utilise this wire?

Which brings me onto the last wire, Purple/White? Obviously, this would go to the Gear Shift switch, but is there somewhere in the dash I could connect to, saving me from routing it down to the Gear Shift?

Your help would be appreciated......

[shcm]

If a Toyota satnav was fitted previously:

then the handbrake and reverse signal may already be on a grey 5 pin connector like this (E in above diag references R19):

However, if the vehicle has previously had just a standard headunit, then my feeling is that part of the harness will not be fitted. I'm not certain though, so have a look. The 5 pin connector is fairly common across the range and pictures pop up all over the place if you google.

If that connector is not there, then first, the reverse signal:

At least one place to access it is described as the driver's side junction box. I can't remember whether the diagram below is left or right hand drive or whether they swap with vehicle type. You'll have to look around behind the glove box or in the equivalent position on the drivers side, and match up the diagrams. From diagram above, Pin 27 and pin 28 on connector 2F would appear to be one place to access the signal.

Now the handbrake signal. The AVH3300BT installation manual says the signal should be connected to the supply side of the switch. That says to me it should be pulled low when active. This is what the Toyota one does also:

From above, places to access this are connector 3Q pin3 or connector 3G pin 5 or 3B pin 1.

Those connectors are on what is described as the passenger side junction box:

Finally the mute. The Toyota AVCLAN connector on their headunits, has a mute input. The newer connector looks like this:

From what I can remember it is a fairly crude mute input, pulling to ground to mute the auto. I expect it is for fairly early phone kits. Unless you have one of these, I don't expect you will find any vehicle harness for this, unless you have a separate Toyota CD changer. say for example. Even then, it would pointless connecting it. I expect you should leave the mute input to the AVH3300BT disconnected, as its installation manual suggests.

Hope that helps

[Chris_Halford]

Thanks for the advice Andy.

As I have the XT3 there was no Sat Nav or cd changer installed, just the stock head unit.

Lets see how I get on at the weekend now. Im sure I'll be back with more questions as things progress.

Im also swapping out the Speakers, no point in changing the head unit whilst retaining the stock Speakers, so maybe after some info regarding those at some point.

Cheers,

Chris

[Chris_Halford]

If it helps for anyone else in future.....

When I pulled the head unit out, all connections were there for SAT-NAV, CD Player and even connector R19 was there. This has made the whole job a lot easier, as I can now splice into the R19 connector for handbrake and reverse signals......

However, 2 points to note on this installation:

1) Why would the senstivity of the aerial go down? When I had the original head unit, the radio worked prefectly. Now however, it doesn't seem to pull the signal in as well. I did notice that the aerial appears to be spliced and there something on the second line going away from the aerial. Anyone know what this is?

2) I bought some adaptors to enable me to fill in the gaps either side of the new head unit. However, I'll be damned if I can get them to fit as if you use the original mounting brackets you cant use the adaptors. I can't use the cage supplied with the head unit as you need to use the mounting brackets. Im stumped, how have other people got round this? For info, this is what I bought: Adaptor

[shcm]

1) Why would the senstivity of the aerial go down? When I had the original head unit, the radio worked prefectly. Now however, it doesn't seem to pull the signal in as well. I did notice that the aerial appears to be spliced and there something on the second line going away from the aerial. Anyone know what this is?

Not sure about the "splice" Is it coax or a normal wire? Pictures can help.

Anyway, Couple of possibilities. One, it's possible you new units radio is not as sensitive as the old own. Two, it's possible there is an antenna amplifier in there and it is no longer getting power.

The above suggests the headunit used to provide the ant amp +ve power supply on the same connector as the front Speakers. (Pin 8). B+ suggests it is a 12V feed, although I can't be 100% about that without measuring it. You probably need to provide an ignition switched supply into pin 8 on the existing old connector. It may not be connected anywhere with your new setup. I haven't checked, does the new system have an output for an ant pre-amp?

Not sure about the brackets. Others have done it, hopefully, they will comment.

[Chris_Halford]

Thanks Andy.

That would make sense in having a 12 volt supply to the ant amp. Its coax, but theres something like a fuse wrapped on the second line. I'll give it a go....

As to the adaptors. I think I may have purchased the wrong ones, as I've also found these Different Adaptors which will enable them to be attached without affecting the original brackets.

[bitman]

hand brake cable from the deck? on the dnx kenwood in our nrg i have just bolt it straight on the deck it self so now you can control the deck any time as it 'thinks' you have the hand brake on

you will have to power your antenna as it's an active antenna normally feed by the 'toyota' deck.

most 'brand' decks do have an antenna cable, pioneer does this with a blue / white cable.

all these things are clearly written down in the installation manual!

[Chris_Halford]

They are indeed bitman, except in the manual the blue/white cable is for connecting to an auto antenna relay control terminal or a system control terminal of a power amp. It also says do not connec to anything else.... There is no other connection for an antenna amplifier mentioned in the manual.

The blue/white cable is rated at 300ma @ 12v. Does this provide a continous supply? and would this be the one to use to supply the 12v to the antenna amp?

Its all very well having the manual for the head unit, but its the connections in the rav that im after hence the reason im on this very forum asking these very questions.

For instance, I didn't realise, without andy's help, that there was a connector which has the parking and reverse signals on it. I knew where they were on the head unit from reading the manual. I did in fact think about hooking the parking wire to a permanent 12v supply to do just as you have done, indeed I may still change my mind, lol! I may do this if I ever purchase a TV unit to go in there, but at the moment its fine as it is (hmmm, now you've got me thinking)

Anyone have any advice on a TV unit?

[Chris_Halford]

Just a quick update. Took the car out for a test drive tonight, tried the Sat Nav out. No problems, and i've put the aerial in the same place as recommended in the Toyota Sat Nav installation, on top of the instrument cluster.

Now going back to this poor FM. I'm now wondering if a poor earth can cause the lower sensitivity on FM as when driving im now noticing a whine which increases and decreases according to the road speed can even hear it faintly when parked up with the engine running. From my old days I know this is to do with the alternator and poor earthing. I actually earthed the Sat Nav to the ground on pin 4 of connecotr R3. Im now regretting this, so next weekend Im going to change this so that it is earth directly to the chassis. Could this also be a factor in the poor FM reception also (along with the missing voltage on the ant amp?)

Surely the ground which exists on the existing wire loom isn't causing this problem is it? I've read several posts that suggest that when you change an OEM unit with an aftermarket one, you should use a seperate ground to the one used on the car loom as per the OEM head unit.

[bitman]

when i installed the gps antenna next to the fm antenna i found that the power wire to power the antenna amp was red.

on our kenwood dnx deck i have used the antenna wire with no problem, deck installed in 2008 and still working.

to install decks like these you will need side plates as you just can on the left side of the deck, i bought them in the us...

[shcm]

Now going back to this poor FM. I'm now wondering if a poor earth can cause the lower sensitivity on FM as when driving im now noticing a whine which increases and decreases according to the road speed can even hear it faintly when parked up with the engine running. From my old days I know this is to do with the alternator and poor earthing. I actually earthed the Sat Nav to the ground on pin 4 of connecotr R3. Im now regretting this, so next weekend Im going to change this so that it is earth directly to the chassis.

If it's alternator whine, it's pitch may change with engine speed. i.e. when you blip the throttle. It can be caused by a number of things. Used to be an indication of a faulty diode in the alternator rectifier, but that's possibly rarer now. Yes, think about all the grounding to the head unit. Drawing out all the paths can help to see what's going on. Ideally, you want a single path back to the Battery, but if it is high impedance (anything other than fractions of an ohm - measure resistance from Battery neg to your head unit ground connection), that will be a contributing factor.

This link is for aircraft, but the principle is the same:

http://www.avweb.com/news/maint/182896-1.html

Speakers should be driven differentially (They usually are). i.e. no ground connection anywhere, just two balanced connections back to the head unit.

Surely the ground which exists on the existing wire loom isn't causing this problem is it?

You would hope not. However, it's possible that the power supply filtering in the new head unit is not as good as the old one and they were relying on that to filter out any ripple from the alternator, with the original unit.

Could this also be a factor in the poor FM reception also (along with the missing voltage on the ant amp?)

Can you hear the whine with another audio source selected, or is it just on FM? I'd check and tackle the points above first.

[Chris_Halford]

Thanks for your details Bitman. As to the side fillers, the ones I bought are Wrong Adaptors but I think the ones I actually require are Right Adaptors, as these would make so much more sense the way they are bolted to the unit. Actually, the GPS antenna was as easy as pie to fit to the top of the instrument cluster, just pulled on the surround and it came away from the dash. Just stuck it to the top then ran the wire to the left hand side behind the head unit. Couldn't believe how easy it was. Works a charm there, picks up on average 10 - 11 satellites.

Andy,

A little bit of development. Yes the whine increases and decreases according to the road speed. When I drove to work this morning I didn't have the sat nav inserted (its a removable part) and it would appear the whine had disappeared which suggets it is indeed a poor earth connection. Yes it did it with other audio sources as well (sounds kind of funny when listening to a CD).

So, 3 jobs to be done this weekend:

Purchase and install the new adaptors

Remove the earth wire from the loom and earth directly to the chassis (thats gonna be fun, not much to mount too behind the glove box)

Use the blue/white wires to provide a 12v supply to pin 8 of the connector

Hopefully this should banish the problems I've got.

[bitman]

Thanks for your details Bitman. As to the side fillers, the ones I bought are Wrong Adaptors but I think the ones I actually require are Right Adaptors, as these would make so much more sense the way they are bolted to the unit. Actually, the GPS antenna was as easy as pie to fit to the top of the instrument cluster, just pulled on the surround and it came away from the dash. Just stuck it to the top then ran the wire to the left hand side behind the head unit. Couldn't believe how easy it was. Works a charm there, picks up on average 10 - 11 satellites.

i had the gps puck there before as that's the place toyota is using too, but my solution is much better when driving in towns with high buildings.

[Chris_Halford]

How did you route the cable for the GPS antenna?

[janew]

I intalled a RAV4 GPS Navi systemfor my brother last month. While it is a OEM device and very easy to install. I attached the pic of cable connection for your reference. hope it is helpful

[bitman]

How did you route the cable for the GPS antenna?

magic

going up the a post then over the roof ceiling following the fm antenna cable. it was a big job but with a very cool eind result