Advice with changing my Head Unit

[Lobby1972]

Hi,

I'm wanting to change my head-unit from the in-build one, (Clarion) to a JVC.
My RR is a 1996 4.6HSD Petrol.
I bought the unit, and was advised that although the speaker connector block didn't fit i would be able to cut/splice the wires together.

Imagine my disgust when i connected the JVC unit to see all nice flashing things on the display but no sound!!!!!!.

I since discovered that the 2 "spare" orange/orange/black speaker wires that were left over when splicing were in fact connected to the amps in the front doors and I'd need to disconnect them to get the sound -or so I'm told!!.

Surely there must be an adapter of some sort or maybe someone can tell me an easier way to re-wire to get my JVC working.....

Thanks -any advice would be great!

Regards

Lobby1972.

[hermanpj]

i changed out the head unit on my classic. havent done this on a p38 range rover, but my guess is the factory put in a similar approach to amplification - 1 dedicated amplifier for front, one for rear, and an un-amplified channel going to the rear powered subwoofer unit (which has an internal amp). So if we think about the front speakers only for a minute, wiring would run from head unit to front amp to left and rigth front speakers. at the front speakers there may be a crossover unit that separates bass and treble, sending treble to the small tweeters in the window frame.

In this layout there will not be any speaker wires running straight from the head unit to the speakers without first going through the amplifier. So I'm not sure why someone would tell you to eliminate the amplifier. This will actually be a lot of trouble to do, see alternatives below.

For now I'd check that you have front left +&- and front right +&- wires from the head unit correctly matched up with wiring going to the front amplifer. If they are crossed over the signal will be out of phase and you won't get sound. You want to also check that you have connceted the amplifier remote on cable to the head unit - this sends a signal to the amplifier to turn on when you turn on the head unit. Once you get the front channel working, repeat analysis for the rear channel and subwoofer channel. Note that subwoofer channel may or may not be separate from rear channel - it may branch off rear channel. Get a wiring diagram for this year model and you will know.

If you go through the above and you still get no sound, then check your JVC documentation carefully about how to connect the unit to an amplifier and make sure you are using the right outputs on the head unit. Assuming the stock amplifier was working before you swapped the head unit, its probably still working now, so your problem is why isnt it getting signal to amplify.

3 other Alternatives

1) replace stock amplifiers with OEM replacement or readily available after market amplifiers of same amplified output. keep factory speaker wiring. may have to run new power, ground, and remote control wiring for amps.

2) Same as above AND replace all factory speaker wiring. This requires a bit more effort and not necessary unless you have poor sound quality. It would give you best sound quality provided you upgraded to better wiring. Howerver larger aftermarket wiring can be hard to route through the narrow wiring channels in these cars.

3) Eliminate amplifiers altogether and run wiring directly to speakers - not recommended as you will have to touch headunit-amp-speaker wiring anyway to eliminate the amp from that series. For all the work this would require, the end result would be under-powered sound.

[Lobby1972]

Thanks for your help - the way i matched the wiring was to look at the block connector going to the JVC and the placing next to the block connector that was plugged into the exisisting clarion unit -but placing them together, ensuring the catch was on the same side for both connectors, i simply made a note of the colour wires that matched up from one connector to another.

Once i had that info, i cut both connectors and used mini block connectors to connector, as an example below:

JVC = Blue - green - Connection to speakers
JVC = blue/black - green/black Connection to speakers

Please note the above is just an example of how i wired - it is not the actual wiring i did.

Anyway, there was 4 set of wires for JVC but 5 sets coming in from speakers, so i was left with orange and orange/black speaker wires - maybe you could suggest where they need to connect in the exisisting set up??

If you need me to supply the actual wiring i did-please let me know and I'll get it?
Thanks for your help.