Simon B Posted May 18, 2010 Share Posted May 18, 2010 This in the plug on the back of my alternator, I think the wires are; Tacho Lamp Sensing The colurs are; White (thick wire) White and red (thin) Black and light yellow (thin) Which one is which? Am guessing the sensing wire is the thickest but do not know which of the other 2 go to my lamp. Quote Link to comment Share on other sites More sharing options...
western Posted May 18, 2010 Share Posted May 18, 2010 are any of the terminals identified, with markings like these Quote Link to comment Share on other sites More sharing options...
Simon B Posted May 18, 2010 Author Share Posted May 18, 2010 Sadly no, or my eyes just could not see it! Its similar to a GM plug I've seen on a vauxhall forum but they did not identify the terminals and the wires were different colours. Quote Link to comment Share on other sites More sharing options...
western Posted May 18, 2010 Share Posted May 18, 2010 Isuzu IIRC is or was part of GM, a good auto electics place should be able to advise further. Quote Link to comment Share on other sites More sharing options...
Bush65 Posted May 18, 2010 Share Posted May 18, 2010 The following pics and quote are for a different Isuzu diesel engine and vehicle to what I'm guessing your alternator is off, but may help. The alternator connections are very simple. The standard Isuzu alternator has an integral regulator which makes it even easier to wire up. Check Fig. 9 on page 6D-14 of the FSM for detailed wiring.Basically, you have three wires going to a round connector on the back of the alternator plus a heavy black wire (B) going to the output stud also on the back of the alternator. This black wire should be heavy enough to handle the full alternator output (70 A) and goes directly to the (+) of the battery (might be a good idea to protect it with a fusible link or big fuse). The black wire (S) from the round connector also goes directly to the (+) of the battery. It serves to sense the actual voltage at the battery which the regulator uses to control the output voltage of the alternator. The white wire (IG) from the round connector goes to the ignition switch and should be hot only when the ignition switch is in the "run" position. This wire turns the charging system on and off. The white with blue stripe (L) is used to control the "Charge" indicator light and is optional. When the alternator is charging, the (L) wire is hot and turns on the "charge indicator relay". Since the indicator light is wired through the normally closed set of contacts on the relay, when the relay is turned on, the indicator light goes out. Hope that makes sense. Quote Link to comment Share on other sites More sharing options...
Bush65 Posted May 18, 2010 Share Posted May 18, 2010 Isuzu IIRC is or was part of GM, a good auto electics place should be able to advise further. My understanding is that GM bought approximately 1/3 of Isuzu at some stage but most of the benefit went to GM and AFAIK Isuzu have bought all or most of that back. GM rebadged some Isuzu vehicles and sold them in several countries. Quote Link to comment Share on other sites More sharing options...
Simon B Posted May 18, 2010 Author Share Posted May 18, 2010 Thanks for an excellent answer, I almost got there, found a voltage regulator diagram (below) which appears to be my 3 pin plug. Also coincides with yours so explosion could be averted! The thing with tach then is red herring, this may then come off fuel pump - more googlisation then! This may be one for the technical archive as I know a number of people have had problems with Isuzu alternators and others have run theirs accidentally in the non-sensed mode so overcharged their batteries, either using water or totalling the battery. I think this alternator is also used in a number of marine applications possibly fitted to Yanmar diesels. Quote Link to comment Share on other sites More sharing options...
Simon B Posted May 18, 2010 Author Share Posted May 18, 2010 More info posted by Gribble on ITOCUK Most of the alternators on troopers are hitachis and as such are load sensing so on the wires the two larger ones are the outputs and one goes to the main supply board and one to the starter main terminal. The smaller one is the charge light or L line which when the key is at ign on earths the batt light but once the alt starts to charge it 'switches ' the earth off and via a relay the batt light goes out. So take your ign feed from the batt light and wire it through a relay to the alt and all should be well , I can post a pic for you to help if you are not keen on electrics If you are going to fit a winch I would put the output wire onto the batt direct as it keeps the winch motor speed up On the injector pump you only need a key switched live to the stop solenoid as the other bit is the CSD or cold start which its never cold enough for in the UK Making more sense now, mind the generous swigs of cheap scotch may have played their part... Quote Link to comment Share on other sites More sharing options...
callum Posted May 18, 2010 Share Posted May 18, 2010 your tacho feed is on the fuel pump, i've written about the wiring for the isuzu tacho on another post somewhere. the cable colours are black and red if i recall. the signal actually comes from the earth. Quote Link to comment Share on other sites More sharing options...
Simon B Posted May 19, 2010 Author Share Posted May 19, 2010 your tacho feed is on the fuel pump, i've written about the wiring for the isuzu tacho on another post somewhere. the cable colours are black and red if i recall. the signal actually comes from the earth. Cheers Callum, Not a priority just yet but might hook a tacho up later on my list of things to do with the P38 box mod. Quote Link to comment Share on other sites More sharing options...
jasonf Posted August 14, 2010 Share Posted August 14, 2010 hi there finally nearly almost there with the 110 mod def to an 2.8 tdi isuzu however is there a trick to getting the altenator to charge the batt or does anyone have the wiring diagram i can look at . thanks jason Quote Link to comment Share on other sites More sharing options...
Aragorn Posted August 14, 2010 Share Posted August 14, 2010 An alternator usually only has two wires... The main output, and a charge warning lamp. If the charge warning lamp isnt connected up properly, some alternators wont exite their internal windings and they wont charge. Quote Link to comment Share on other sites More sharing options...
errol209 Posted August 14, 2010 Share Posted August 14, 2010 An older alternator usually only has two wires... A modern (like this millenium) battery-sensed jobbie will have three (12V out, charge warning out and sense wire), and won't charge properly unless the sense wire is connected to the battery, IIRC. Quote Link to comment Share on other sites More sharing options...
Aragorn Posted August 14, 2010 Share Posted August 14, 2010 The alternator on the Audi is a modern thing (ive got three, one bosch and two valeo) and it just has two, one bolted fixing for output and the sense/warning wire to the dash. I think the sensing is still done via the charge indicator lamp? Quote Link to comment Share on other sites More sharing options...
Outdoor Ed Posted August 14, 2010 Share Posted August 14, 2010 Erm...... Give me a second and I shall check under the bonnet of the 90 and look at my 2.8TD Isuzu Quote Link to comment Share on other sites More sharing options...
Outdoor Ed Posted August 14, 2010 Share Posted August 14, 2010 Right then I am guessing that you are talking about the 3 wires that come of the back of the alternator at the top from the plug? You should have: Black with white stripe - This goes to the Yellow/Brown wire in the Land Rover White with red stripe - This goes to the Red/Yellow wire (sense wire) Solid White - This is your extra wire just run a new wire from this and connect it to the back of the Starter Motor The other thicker wires coming off the bottom of the alternaor (can't tell the color too much muck and electrical tape), these should connect to your thick brown wires in the Land Rover. Having said all this I connected the sense wire on mine and it just melted it, I never bothered changing it and reconnecting it and all charges and works fine. Hope this is of some help. Quote Link to comment Share on other sites More sharing options...
Bush65 Posted August 14, 2010 Share Posted August 14, 2010 There are other threads here on Isuzu conversions that have covered your questions - I know I have posted Isuzu charging circuit diagrams (with wire colours and function) in at least one of them. Quote Link to comment Share on other sites More sharing options...
Simon B Posted August 15, 2010 Author Share Posted August 15, 2010 (edited) Thread on my alternator problem includes Bushie's answer and diagram Edited August 15, 2010 by western 2 threads on same subject now merged into 1 thread Quote Link to comment Share on other sites More sharing options...
errol209 Posted August 15, 2010 Share Posted August 15, 2010 Thread on my alternator problem includes Bushie's answer and diagram http://forums.lr4x4.com/index.php?showtopic=56508&st=0&p=499139entry499139 Cant get link icon to work properly? Advice here Quote Link to comment Share on other sites More sharing options...
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