andy2986 Posted December 24, 2011 Share Posted December 24, 2011 Hi All, Car is a 97 3.9V8 Disco. Recent History. Have just changed the starter motor, I disconnected the batteries whilst I did this, due to other events I left them disconnected for three days. When I leave the Disco for long periods I always disconnect the batteries for months at a time and have had no ill effects. Fault. The electric windows, central locking do not work. Hazards don't work (but indicators do) Horn doesn't work The interior light, radio, CB (cb is wired to interior light circuit) doesn't work If any of the above i.e. interior light does work its like it shorts out or pulls down the electrical system. For instance if the radio does come on, if you turn on the interior light the radio goes off and then nothing works for a few minuets. The alarm keeps immobilising the engine, i have taken out the appropriate fuses to disable the alarm in the mean time... The engine starts and runs fine, lights work, car drives perfectly. All instruments work. Problem seems to be locking,windows, alarm, horn, hazards interior light related.... I have tried a jump lead from the neg to the engine incase its earth related, my feeling is there is an earth fault somewhere but I have no idea where.. Any thoughts please help as I need to get this sorted ASAP Cheers guys Andy Quote Link to comment Share on other sites More sharing options...
Paul Woodward Posted December 24, 2011 Share Posted December 24, 2011 I'd say it's more likely a problem on the supply side. Not sure about windows but everything else not working is fed from a permanent live. If you look on the wiring diagram you'll probably find that all these items are fed from a common point somewhere. Sorry don't have a Disco diagram to look at! Good luck! Quote Link to comment Share on other sites More sharing options...
andy2986 Posted December 24, 2011 Author Share Posted December 24, 2011 OK the only thing I think is common with all the above is the "muti function unit" The bonging, interior light, hazards, windows and locking/alarm seem to have this in common... the Haynes wiring diagrams are not all that great.. anyone know where it is ???? Quote Link to comment Share on other sites More sharing options...
teabag Posted December 24, 2011 Share Posted December 24, 2011 Pluged into the rear of your interior fuse box Quote Link to comment Share on other sites More sharing options...
andy2986 Posted December 24, 2011 Author Share Posted December 24, 2011 Hi Thanks teabag ! I found the MFU popped the lid off nothing untoward that I can see, new one from rimmers is £200.00 It would appear that all the odd problem things are fused from the satellite 2 fuse box....windows,locks, interior light/radio... The fuse is good in the engine bay although I noticed that when I meter the voltage with the ignition off and the MFU out/unplugged I get 12v as I would expect, this then drops to 3v when the ignition is switched on.... Quote Link to comment Share on other sites More sharing options...
andy2986 Posted December 29, 2011 Author Share Posted December 29, 2011 OK then, hope someone can help. Its not the MFU Someone brought one round yesterday (thanks John) I fitted it this morning.... nothing am now cross with myself for trying to make the diagnoses fit my symptoms... So the latest, Satellite 2 fuse box has no voltage to it. it is supplied by two wires, (its in two parts) according to Haynes this box is fed from the under bonnet fuse box. Ive found the correct wire (according to Hayne colours) and there is no continuity from under bonnet fuse box to Sat 2 fuse box. There are TWO wires feeding Sat 2 but only 1 wire being fed from under bonnet Fuse Box. (so somewhere this wire must be split and or switched) according to Haynes the wire should go direct... Ive asked for someone to point me in the direction of a better wiring diagram.. This is really doing my head in now My kids are round till the new year so I can only spend the odd hour or two on it while they're playing space invaders or whatever teenagers do... So will be able to devote more time to it in the new year If anyone has any ideas or pointers please let me know Andy Quote Link to comment Share on other sites More sharing options...
redneck Posted December 29, 2011 Share Posted December 29, 2011 Satellite 2 fuse box has no voltage to it. it is supplied by two wires, (its in two parts) according to Haynes this box is fed from the under bonnet fuse box. Ive found the correct wire (according to Hayne colours) and there is no continuity from under bonnet fuse box to Sat 2 fuse box. There are TWO wires feeding Sat 2 but only 1 wire being fed from under bonnet Fuse Box. (so somewhere this wire must be split and or switched) according to Haynes the wire should go direct... Andy Just had a quick look at the H****es manual, looks like you nailed it with either the under bonnet fuse box (you have checked the fuse and the condition of the contacts etc????) or the wire (brown and purple) is damaged. Check the wire connections first. Run a jumper cable to confirm if that is your problem. Quote Link to comment Share on other sites More sharing options...
simonr Posted December 29, 2011 Share Posted December 29, 2011 Check the battery connections, after where it connects to the starter - as that obviously works. Si Quote Link to comment Share on other sites More sharing options...
andy2986 Posted December 30, 2011 Author Share Posted December 30, 2011 Hi all, well I've managed to open the Rave pdf from the tech archive. The lx diagrams are just what I was hoping for. Much more detail and have helped me make a bit of sense of my problem. The under bonnet feed to Sat2 fuse box has a splice on it, (splice 226) as soon as I get a chance I will try and track it down Quote Link to comment Share on other sites More sharing options...
robp Posted December 30, 2011 Share Posted December 30, 2011 Hi all, well I've managed to open the Rave pdf from the tech archive. The lx diagrams are just what I was hoping for. Much more detail and have helped me make a bit of sense of my problem. The under bonnet feed to Sat2 fuse box has a splice on it, (splice 226) as soon as I get a chance I will try and track it down Andy, Splice 226 will be located under dashboard area. So would suggest looking behind fuse boxes. The splice numbering system in the diagrams indicate what area the splice is located in. 100's under bonnet 200's dashboard 300's front seat area etc Quote Link to comment Share on other sites More sharing options...
shtmekanic Posted December 31, 2011 Share Posted December 31, 2011 Hi All, Car is a 97 3.9V8 Disco. Recent History. Have just changed the starter motor, I disconnected the batteries whilst I did this, due to other events I left them disconnected for three days. When I leave the Disco for long periods I always disconnect the batteries for months at a time and have had no ill effects. Fault. The electric windows, central locking do not work. Hazards don't work (but indicators do) Horn doesn't work The interior light, radio, CB (cb is wired to interior light circuit) doesn't work If any of the above i.e. interior light does work its like it shorts out or pulls down the electrical system. For instance if the radio does come on, if you turn on the interior light the radio goes off and then nothing works for a few minuets. The alarm keeps immobilising the engine, i have taken out the appropriate fuses to disable the alarm in the mean time... The engine starts and runs fine, lights work, car drives perfectly. All instruments work. Problem seems to be locking,windows, alarm, horn, hazards interior light related.... I have tried a jump lead from the neg to the engine incase its earth related, my feeling is there is an earth fault somewhere but I have no idea where.. Any thoughts please help as I need to get this sorted ASAP Cheers guys Andy Hi Andy, just read through the above, and sounds like an alarm issue which would affect the lights, central locking and windows... wonder whether the alarm unit is at fault...? good luck John. Quote Link to comment Share on other sites More sharing options...
andy2986 Posted January 3, 2012 Author Share Posted January 3, 2012 Right Then ! Its all fixed!! Once I had my copy of the Rave wiring diagrams rather than the Haynes crayon drawings it was easier to see what was what. Turns out that the main loom had been damaged near the under bonnet fuse box. Some of the wires had a small nick in them. The only thing I can think of is I must have nicked the wires when I was patching the inner wing. I did this THREE years ago !!! the nick in the wires had slowly sulphated (?) as there was a bluish coating to the wires some of which had been eaten all the way through ( total of 6 broken wires !!). To be honest Im surprised the any of the electrics worked at all. I had been out in the Disco the other day and had gone through a few fords, some off them were quite deep (above headlamps) so all that water must have been the final straw for the loom. So all soldered up and heat shrinked now and as good as new. Thankyou all those who helped me out. Just the exhaust to sort out now.. Oh, and the rear leaking diff seal... and the rear passenger lock spring.. sure there will be more stuff to fix I haven't thought of.... Andy Quote Link to comment Share on other sites More sharing options...
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