neil00001 Posted January 15, 2009 Share Posted January 15, 2009 Hi All, Been trying to get my interior lights working so when I open the doors they come on, they work manually from the switch on the lamp itself. What I am trying to find is where all the earth returns connect, On the lamp i see 2 purple wires (connector) and an earth on the chassis of the lamp. None of the doors activate the lamps. I have followed the puple and black wires down the right hand side A pillar, down behind the binacle is where I lose them. glad of any advice. Cheers Quote Link to comment Share on other sites More sharing options...
DaveSIIA Posted January 15, 2009 Share Posted January 15, 2009 There should be a pin switch in each of the front door pillars. These often corrode to give poor contact and the interior light fails to come on. Remove one of the pin switches and the purple/black wire should be attached to a spade terminal on the back. Ground the wire and the interior light should come on. If so, clean/replace the pin switch. Quote Link to comment Share on other sites More sharing options...
neil00001 Posted January 15, 2009 Author Share Posted January 15, 2009 There should be a pin switch in each of the front door pillars. These often corrode to give poor contact and the interior light fails to come on. Remove one of the pin switches and the purple/black wire should be attached to a spade terminal on the back. Ground the wire and the interior light should come on. If so, clean/replace the pin switch. Thanks Dave, but I have gone around all 5 switches and cleaned them up, which is why I think the problem is to do with the earth return, but I cant find where they all connect up.. Cheers Quote Link to comment Share on other sites More sharing options...
DaveSIIA Posted January 15, 2009 Share Posted January 15, 2009 What year / spec is the vehicle? Does it have the factory fit immobiliser? Quote Link to comment Share on other sites More sharing options...
TimR Posted January 15, 2009 Share Posted January 15, 2009 I have the same problem in my 98 CSW - I do have an immobiliser fitted and the interior lights act very strangely at times (turn on but not of, wont work at all etc) Quote Link to comment Share on other sites More sharing options...
paulnb57 Posted January 15, 2009 Share Posted January 15, 2009 IIRC the door switches are the earth connection. The light is live and the door switches complete the circuit? Paul Quote Link to comment Share on other sites More sharing options...
western Posted January 15, 2009 Share Posted January 15, 2009 the interoir light itself is earthed to the inner rib of the roof too. least mine are. Quote Link to comment Share on other sites More sharing options...
DaveSIIA Posted January 16, 2009 Share Posted January 16, 2009 I have to hand only the wiring diagrams for the 97 model year 300Tdi. The 'basic' set up takes a Purple/Blue wire from the interior light to ground via the door switch. It should be straight forward to test the interior light by grounding this wire at the point where it leaves the light assembly. If that works, then it is a matter of tracing the wires through to the door switchess and testing. The 'immobiliser' set up is similar to the 'basic' except that there is an ECU-ALARM box in the path to earth. This is fed by a Purple/White wire from the interior lights. Purple/Blue wires run from the box to ground via the door switches (except for the drivers door which is Slate/White wire to the switch). The wiring configuration for a 1990 110 should be similar to the 'basic' version of the 300Tdi. The fact that the light can be switched on manually rules out a problem with power feed and earth to the unit and suggests a fault between the unit and the door switches. The interior light switch on the 300 Tdi has three positions - Off/Door/On. Does the 1990 unit have the same switch options, and is the door controlled position selecting correctly? Quote Link to comment Share on other sites More sharing options...
neil00001 Posted January 16, 2009 Author Share Posted January 16, 2009 Hi Dave, 1990 110 CSW While testing I had the switch position in the centre on both lamps, I started with the rear lamp working from the rear door, working to the front. My problem is the way I see it is the earth that goes to the lamps from all 5 doors. This is the joint I am looking for as that seems to be the point of failure as not one switch will light up the lamps. Am I right to assume that when one door is opened, both courtesy lamps will light up.... Auto electrics dont bother me in the slightest, but while tracing the purple wires behind the binacle I came to a stop where they run into the centre of the dash, do they go into the engine compartment from there? Once I put everything back togeather I adjusted the sweep of my wipers taking out the slack of the worm gear, 1 out of 2 aint bad I suppose. Until I went for a drive and now have no hi beam flash....... One step forward 2 steps back..............Joys of owning a Land Rover, I sometimes think the MOD made a deal with LR to make them this way, if there was anoth big war, there would be plenty of mechanics available in the civilian world to keep the fleet of LR's on the road. They wouldnt need to go to Jobserve.com would they? Quote Link to comment Share on other sites More sharing options...
DaveSIIA Posted January 16, 2009 Share Posted January 16, 2009 Hi Dave,1990 110 CSW While testing I had the switch position in the centre on both lamps, I started with the rear lamp working from the rear door, working to the front. My problem is the way I see it is the earth that goes to the lamps from all 5 doors. This is the joint I am looking for as that seems to be the point of failure as not one switch will light up the lamps. Am I right to assume that when one door is opened, both courtesy lamps will light up.... I would have to do some searching around for the 1990 wiring diagram, but things moved slowly at LR, so there is a good posibility the interior lighting will be configured the same on a 300Tdi. On my 1994 (95 MY) 110 CSW, the front and rear lights are independent. Open the front doors and only the front light comes on, likewise rear only. BTW: My 300Tdi CSW left the factory with light switches on the two front doors and the rear door only. The rear side doors are not wired. It might be that a previous owner has added the middle row doors in to the mix, so wiring could be somewhat non-standard. There should be three terminals on each interior light (colours may be different on yours depending if there have been some modifications) Purple - permanently live supply Black - earth Purple/blue - switched to ground by door opening Probing with a DMM should identify #1 & #2. The third wire could be identified through a continuity check with doors open/closed. This would help trace the problem to the light or the door switch wiring. (After writing this, I've had another thought - the interior light switch has three positions off/door/on. You know one position brings the light on and the other two leave it off. Have you checked both off positions when opening the doors? Simple, but sometime problems are.) Quote Link to comment Share on other sites More sharing options...
yellow Posted January 16, 2009 Share Posted January 16, 2009 Neill, Are you sure that there is not a dash switch which is in an off position, as a remnant of the old 110s? Door switches are a luxury you know... Quote Link to comment Share on other sites More sharing options...
DaveSIIA Posted January 16, 2009 Share Posted January 16, 2009 I've done a bit more digging and found a wiring diagram for 1986 on models. It shows the live feed on purple and the black returning from the the light to a connector. From the connector, the cable becomes purple/blue and goes to the door switches. This would explain why the black goes down behind the binnacle. You will be looking for the change of wiring either in the instrument pod or on the engine side of the bulkhead. Earthing the black would demonstrate that the light and switch setting have the potential to work with the door switches. If that works okay then there is continuity testing and possibly a bit of rummaging in the wiring to trace the fault. The wiring diagram doesn't show any other switches controlling the interior light. HTH Quote Link to comment Share on other sites More sharing options...
neil00001 Posted January 17, 2009 Author Share Posted January 17, 2009 I've done a bit more digging and found a wiring diagram for 1986 on models. It shows the live feed on purple and the black returning from the the light to a connector. From the connector, the cable becomes purple/blue and goes to the door switches. This would explain why the black goes down behind the binnacle. You will be looking for the change of wiring either in the instrument pod or on the engine side of the bulkhead.Earthing the black would demonstrate that the light and switch setting have the potential to work with the door switches. If that works okay then there is continuity testing and possibly a bit of rummaging in the wiring to trace the fault. The wiring diagram doesn't show any other switches controlling the interior light. HTH Dave, Thanks for the info and the time taken to write up, Looks like I will be rewiring the lights in the next couple of days, or at least correcting the bodges made by the last owner. Yellow, cant find a 3 way switch under the dashboard, but it wouldn't surprise me to be honest, have you still got some bits of RHD dashboard? Thanks again for the help all !! Cheers Quote Link to comment Share on other sites More sharing options...
western Posted January 17, 2009 Share Posted January 17, 2009 on 300tdi vehicles the interior light switch was relocated from the dash 3 switch panel to the interior light itself. some had the rear door switch & loadbay interior light as a seperate circuit & later vehicles have the door switches operating both lights provided the switch is in the centre position. Quote Link to comment Share on other sites More sharing options...
DaveSIIA Posted January 17, 2009 Share Posted January 17, 2009 Attached are the wiring diagrams for the 90/110 (pre-200Tdi). The 200Tdi supplement appears to make no reference to different wiring diagrams. 300Tdi are somewhat different, and easier to follow diagrams (per earlier post). Def90_110_Wiring.pdf Quote Link to comment Share on other sites More sharing options...
neil00001 Posted April 28, 2009 Author Share Posted April 28, 2009 Whooo hoooooo !!!! Ok Finally managed to sort out the interior lights, Binacle off, door switches out, interoir light out and trace wires. All the wires came to an unconnected grey connector behind the binacle. Purple blue to Interior light White grey to the driver door White black to the passenger door. Connect all three togeather and hey presto all 5 doors work the 2 Interior lights. Again thanks to the forum !!!! Cheers, Quote Link to comment Share on other sites More sharing options...
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