Adrian Flux : 0800 916 1257

Isuzu Trooper Owners Club UK™
Isuzu Trooper, Rodeo, Bighorn, Mu & VehiCROSS Owners Club
 
 FAQFAQ   SearchSearch   Watched TopicsWatched Topics   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your personal messagesLog in to check your personal messages   Log inLog in 
CalendarCalendar  ITOCUK Club ShopClub Shop  ITOCUK Classified Ads serviceClassified Ads
ITOCUK HomeITOCUK Home   dynamic online chat serviceChatrooms  Yellow Diamond ClubsYellow Diamond Clubs

little help please ?


 
Post new topic   Reply to topic    Isuzu Trooper Owners Club UK™ Forum Index -> ICE
View previous topic :: View next topic  
Author Message
rick 1
*


Joined: 04 Oct 2014
Posts: 12
Location: kent

PostPosted: Thu Apr 23, 2015 19:57    Post subject: little help please ? Reply with quote

hello guys.its goes like this.i was given a new head unit.the one ive got is rubbish so ..i took all the dash panel off..unplugged all
the switches..plugged in my new radio (iso block)..turn the ignition...nothing..no power to the head unit..so i unplugged it..
plugged my old head unit back in..nothing...no power to that head unit either !!!..i assumed id blown a fuse some how
but the only fuse i can find is in the drivers footwell it says audio...ive changed it...still no power..

am i missing something ? ? ?....thanks in advance..
Back to top
View user's profile Send personal message
Google
Sponsor





PostPosted: Thu Apr 23, 2015 19:57    Post subject: Google Ads keep this community free to join!


Back to top
Matt Quinn
***


Joined: 08 Dec 2009
Posts: 233
Location: Near Edinburgh

PostPosted: Thu Apr 23, 2015 22:02    Post subject: Reply with quote

There's not an inline fuse in the ISO adaptor by any chance?

- Whoever fitted the old radio could have picked up the feeds from any of several places; so it's a case of checking through likely suspects - People often pick up a feed from the lighter socket for instance.  - Is there anything else that WAS working which isn't now? - Might give you a clue as to where to look.

Buying a cheap multimeter is a good idea if you're going to fiddle with this sort of thing.
Back to top
View user's profile Send personal message Visit poster's website
rick 1
*


Joined: 04 Oct 2014
Posts: 12
Location: kent

PostPosted: Fri Apr 24, 2015 14:52    Post subject: Reply with quote

right..ive found a fuse thats blowing..its the clock one..which i now know serves as a second fuse for the head unit.
the problem is the iso block and the cars plug..(someones cut it all about before )the wires do not match..

so im going to have re do it all ..what i need now is the wireing diagram for a imported trooper (92 plate)
think ive seen one whilst snooping around the forum....so im off to search for that ...thanks for reply  Wink

rickie
Back to top
View user's profile Send personal message
Matt Quinn
***


Joined: 08 Dec 2009
Posts: 233
Location: Near Edinburgh

PostPosted: Fri Apr 24, 2015 15:08    Post subject: Reply with quote

The clock feed isn't meant for much of a load...

No... What you need is a small multimeter.  If the wiring's already been 'got at' to any extend the diagram may not help you, and you might make things worse.

Assuming the speaker connections are correct you have no problem there...  

A permanent live feed is best obtained from the battery - through an inline fuse of course.  If the cigarette lighter 'switches' with the ignition (some do some don't) that will be a good place to take your switched feed. - Personally I have a relay which is switched from a line which goes 'live' with the ignition, and switches the battery feed onto the 'ign' line for the radio.

'Earth' ...I found a convenient bolt behind the ashtray/lower DIN area which serves well...
Back to top
View user's profile Send personal message Visit poster's website
rick 1
*


Joined: 04 Oct 2014
Posts: 12
Location: kent

PostPosted: Sat Apr 25, 2015 1:09    Post subject: Reply with quote

right okay..gotcha..i didnt think of taking a live from the lighter..(im not electrician as you can probably tell lol)
but thats a good idea...also thanks for the tip for the earth..

its such a mess..its all been joined with bullet connectors and then joined again with more bullet connectors
with all different color wires !!.i cant find the live so i think your way is the way to go

also the head unit only had one metal bracket holding it in place  Rolling Eyes

ill have a go ..failing that.ill have to admit defeat and take it to the dreaded halfords ..

cheers  Wink .
Back to top
View user's profile Send personal message
Rhanagar
Lifetime member
Lifetime member


Joined: 12 Jan 2010
Posts: 4861
Location: Preston, Lancs.

PostPosted: Sat Apr 25, 2015 7:47    Post subject: Reply with quote

If it gets too much then take it to a local audio specialist. They will be far quicker and probably better than Halfords.
_________________
1990 Isuzu Bighorn LWB Mk.I 2.8TD Manual Lotus Edition
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto Lotus Edition

Deceased
1994 Isuzu Bighorn LWB Mk.II 3.1TD Auto LS

Back to top
View user's profile Send personal message
Matt Quinn
***


Joined: 08 Dec 2009
Posts: 233
Location: Near Edinburgh

PostPosted: Sat Apr 25, 2015 10:08    Post subject: Reply with quote

LOL Halfords are about the last place I'd go...  Very Happy  I'd ask the cat first... If you don't have a cat buy/adopt one!

If the wiring really is such a mess I'd advise just 'abandoning' it (at least on the power side) and giving yourself some fresh feeds from known, sound connections...  Bullet connections aren't my favourite thing, but nor are they the source of all the world's evils. On the speaker side of the ISO - IF all four are working with your old radio - I'd leave well alone.  It's more likely the power side that's been bodged.

OK.. So let's start with the ISO connector.   Some detail here...

http://en.wikipedia.org/wiki/Connectors_for_car_audio

And a pinout here...



As you can see your ISO connector is really TWO connectors; one for power, the other for loudspeakers. Sometimes they're cast as one piece (though they will snap apart) sometimes they are two independent connectors - doesn't matter, they're the same thing. You will also note that they have 'keys' that mean you can't put one plug in the other socket even if the connector is physically split.

Firstly the loudspeakers...   Four pairs, each with a positive and negative.  A few things to know.

1) If you get the + and - leads to a loudspeaker the wrong way round it won't harm the radio, it'll just sound bad.

2) If you short them out it may blow the radio's output transistors...

3) Similarly some radios may be damaged by an open circuit.

4) Don't get the 'pairs' wrong (see diagram) - if you do you run the risk of connecting the different output channels of the radio together with unpredictable and probably-not-good results!

IF all four speakers work fine at the moment then fret not - and footer not - with it.

If they don't you're going to need your meter ( for around the house I recommend Maplin's N73BZ) on its resistance (NOT continuity) range to check for dead shorts across the pairs... Now; it's important to realise that a loudspeaker will exhibit a very LOW resistance reading - but it shouldn't read '0' (open) or (on most meters) give the 'dead short' reading.  See your meter's instructions for what this 'dead short' indication is - this is often just a '1' on the far-right of the display as opposed to a 1.0 for 1Ω - Very often a speaker will give a slight 'click' as the meter probes connect, indicating that it's working... DON'T hold meter probes onto a speaker for any longer than is necessary to establish it's not shorted out.

The worst case-scenario in terms of fault finding here is that you wind up with each speaker in turn out of the door cards and disconnected while you use the continuity range of your meter to trace each wire back to the connector at the dash - unlikely you'll have to go there if your existing unit has been working.

Next... And this IS where I suspect your problems are...  Is powering the thing!

Power-wise your radio has two 'live' feeds to it. One is 'always on' the other switches with the ignition.  The purpose of this is to allow the radio to retain it's memory settings and come on automatically when the car is started. - This is where many people start to develop misconceptions. Radios can draw a lot of current when running, but the quiescent current will be tiny.  On some radios the line that goes direct to the battery is the one that supplies the main power to the set when it's running (the 'ignition sense wire' just triggers some sort of internal relay circuit); on others the 'battery' lead seems to just supply the quiescent (standby) feed...

This is why perhaps your old radio was quite happy to be fed from the clock circuit, but the new one pops the fuse... And no; fitting a bigger fuse isn't the answer as the fuses are there to protect the car's wiring.

So...  Looking at the 'power' side of the ISO...

Pin 8 is 'earth' or more accurately the vehicle's chassis. As I mentioned before there is (on my car at least) a very convenient bolt behind the lower DIN/ashtray area to which an 'earth' can be attached.  

Pin 4 is the permanent feed...  Personally I'd strongly recommend running a new line direct to the battery. This MUST terminate in an suitably rated inline fuse at the radio end and the convenient point to add it is at the ISO block - most have them already. It's also not a bad idea to add a second (larger) inline fuse at the battery end as this allows that 'live' to be tapped later on for additional smaller accessories, and it's arguably a tad safer!

Pin 7 is the switched feed...   Trickier as you have two choices here.  

Personally I feed my radios and other additional equipment (the details of which I won't bore you with) each via 6A mains flex using the 'convention' of brown for the permanent feed and blue for the switched. These cables are fed through the bulkhead and terminated in the engine compartment.  The permanent feed straight to the battery (another inline fuse here does no harm as I say) and the switched feed via a RELAY (and yet another inline fuse) also from the battery.

The relay(s) gets it's 'trigger' (in my case) from a switched live at the igntion switch. The whole point of a relay being that it draws very little current and thus places little or no stress on the existing wiring, whilst allowing a (potentially) much larger current to be switched without a problem.

Why go to all that bother?  Well it means I'm 100% sure the 'switched' feed is reliably connected straight to the battery, has no unknown taps or branches off it, and can therefore happily supply the equipment its connected to without stressing any part of the cars 'native' wiring.  - Some people even use 3-core mains taking the 'earth' connection directly from the battery!

The other choice is of course to take the feed from the lighter socket (IF it's switched from the ignition of course) as I mentioned. 'less satisfactory' in my pedantic view; but nine out of ten cats would be purrrfectly happy with the arrangement.   Very Happy

Pin 6 - Aerial...  This, I assume works on your old radio?  Some people wire these to the switched feed so they just come up when the car's running regardless. Personally my electric aerial got broken and replaced with a fixed one.

Pin 5 - Illumination...  Scotchlock into a dashboard light feed (hunt for 12v with your meter - switched with the lights of course)  Personally I never bother.

Pins 1,2,3, will only be of consequence if you've a separate hand-free kit.  

If you're struggling at all just holler!


Last edited by Matt Quinn on Sat Apr 25, 2015 10:36; edited 4 times in total
Back to top
View user's profile Send personal message Visit poster's website
Matt Quinn
***


Joined: 08 Dec 2009
Posts: 233
Location: Near Edinburgh

PostPosted: Sat Apr 25, 2015 10:16    Post subject: Reply with quote

Doh... Double post.
Back to top
View user's profile Send personal message Visit poster's website
rick 1
*


Joined: 04 Oct 2014
Posts: 12
Location: kent

PostPosted: Sun Apr 26, 2015 17:27    Post subject: Reply with quote

matt that post was brilliant !! i now know alot more than i did ..
im gonna give it a go during the week..i think i can probably sus it out..

thankyou very much mate  Wink

(i really didnt want to go to halfords)  Very Happy
Back to top
View user's profile Send personal message
Display posts from previous:   
Post new topic   Reply to topic    Isuzu Trooper Owners Club UK™ Forum Index -> ICE All times are GMT + 1 Hour
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


All contents © Hobson's Choice IT Solutions Ltd 1997 on
Powered by phpBB © 2001, 2005 phpBB Group