Discovery 1 94 , no heaters, wipers, mirrors, windows

r8hilbocus said:

I just checked the resistance between the footwell earth plug and the body, it was zero showing the earth point is good, I then measured the resistance between one of the black wires on the relays and the earth plug and it showed over 100 which is confusing? Also if I have the engine fusebox with the larger square fusible links does it mean there isn't any of the spliced fuses in the diagram you posted?

Thanks

Click to expand...

That TSB is about earlyer modells than yours, i posted it just to clarify... the black wires to the relay's coils should be zero to ground if it's above 100 that's the problem, means that somewhere in a connector there is a bad contact on that earth path, splice with a grounded wire into that black wire see what happens

I'm also wondering if there's a short somewhere as the feed to the coil side of the heater relay is showing continuity to the earth for some reason?

Click to expand...

that's not OK

...if it's a blue/red wire with continuity to earth on the heater relay's coil that one shoud come with power from the ignition load relay K127 from fuse F6 sattelite fusebox

sierrafery said:

...if it's a blue/red wire with continuity to earth on the heater relay's coil that one shoud come with power from the ignition load relay K127 from fuse F6 sattelite fusebox

View attachment 315825

Click to expand...

Thanks, didn't realize that rear relay was for ignition, I thought that was the heater blower one because that's the one I bypassed by bridging the pins and it triggered the heaters. Does that mean my relays are in a different order or am I bypassing the ignition load?

r8hilbocus said:

Thanks, didn't realize that rear relay was for ignition, I thought that was the heater blower one because that's the one I bypassed by bridging the pins and it triggered the heaters. Does that mean my relays are in a different order or am I bypassing the ignition load?

Click to expand...

I can't tell you that from distance, you'll have to find a suitable diagram and work with that if you know how to identify the circuits based on the wire colour codes, all i can give you is for '95 modell https://smallpdf.com/file#s=97125f09-a792-497f-a4b4-421f883e6e9d

Yes I did try identifying the relays by the wire colours in the haynes diagrams but none of them seem to have all four wires that match, so I'm never sure which one I'm referring to. It's like its got a 200 wiring loom but with the engine bay fuses of a 300!

Unfortunately there's no way to properly troubleshoot things untill you dont know exactly what's what

sierrafery said:

Unfortunately there's no way to properly troubleshoot things untill you dont know exactly what's what

Click to expand...

Quite right, I'm a bit out of my depth with electronics when I can't visualize the circuit layout! Thanks for the advice though, I'll let you know if I find the problem. Could there be a short inside the fusebox itself?

r8hilbocus said:

Could there be a short inside the fusebox itself?

Click to expand...

That's always a possibility

r8hilbocus said:

Yes I did try identifying the relays by the wire colours in the haynes diagrams but none of them seem to have all four wires that match, so I'm never sure which one I'm referring to. It's like its got a 200 wiring loom but with the engine bay fuses of a 300!

Click to expand...

Ok by now you have the blower relay confusingly called ignition load relay, and hopefully you have now found the front wiper relay.
The mirrors don't have a relay and the electric windows has only an ECU.

As far as a “short” in electrical terms that means a fuse has blown, if fitted and if not you’ll will have a hot piece of wire and maybe a burnt out component .

A ‘break’ in a circuit maybe a possibility

discool said:

Ok by now you have the blower relay confusingly called ignition load relay, and hopefully you have now found the front wiper relay.
The mirrors don't have a relay and the electric windows has only an ECU.

As far as a “short” in electrical terms that means a fuse has blown, if fitted and if not you’ll will have a hot piece of wire and maybe a burnt out component .

A ‘break’ in a circuit maybe a possibility

Click to expand...

Ah does that mean I've been bypassing the ignition load relay, if so why are only the heaters operating when I do this? Also, its a 94 so I don't think the windows have a BCU. Since the mirrors aren't working as well does that imply the initial auxiliary feed is the issue since it's not relay related, does it split off to the specific circuits that aren't working?

Thanks

r8hilbocus said:

Ah does that mean I've been bypassing the ignition load relay, if so why are only the heaters operating when I do this? Also, its a 94 so I don't think the windows have a BCU. Since the mirrors aren't working as well does that imply the initial auxiliary feed is the issue since it's not relay related, does it split off to the specific circuits that aren't working?

Thanks

Click to expand...

Wasn’t you bridging a relay supply to the coil directly and running the fan, therefore bypassing the operating switch circuit?

D1 Windows have an electronic control unit ECU for four windows to control and interfaced with other bits and bobs if fitted to the vehicle, so has three fused feeds to it.

Mirrors have a direct feed from the dash fuse board to the mirror adjustment switch.

The Haynes Manual or even the owners handbook will tell you the fuse numbers, I believe the fuse positions are also printed on the rear of the fuse board cover.

You can download for free the LR workshop manuals either a 1994 or a 1997 which has sunroofs, electric seats, AC etc that some later D1 models had.

My quick search shows me two versions of electrical manuals, 5th and 7th edition for the D1, and apparently the same.






Sent from my iPad on a train.

discool said:

My quick search shows me two versions of electrical manuals, 5th and 7th edition for the D1, and apparently the same.

https://www.fuddymuckers.co.uk/rtfm/Discovery/D1/Discovery_1_LRL-0077-ENX-5-1998-04_Electrical_Troubleshooting_Manual_5th_Edition.pdf

http://www.landy.ee/manuals/electricity/Disco_Elec.Troubleshooting%20Manual%20-%20LRL0077ENG%20(1997).pdf

Sent from my iPad on a train.

Click to expand...

Thanks, the diagrams at the end are really helpful for identifying the relays but have now got me even more confused how only the heaters are working when bridging the ignition load relay k127, does it not supply anything else. Also, it still allows me to adjust the fan speeds meaning I can't be bypassing the switch?

So, to be clear, when you bridge that relay which you think it's ignition load the blower starts directly or you have to switch it on? also what colour wires it has on the contact sides?

sierrafery said:

So, to be clear, when you bridge that relay which you think it's ignition load the blower starts directly or you have to switch it on? also what colour wires it has on the contact sides?

Click to expand...

When I bridge it, I can switch on and off at the slider switch and control the speed.

r8hilbocus said:

When I bridge it, I can switch on and off at the slider switch and control the speed.

Click to expand...

Ok now that clear it appears that the ignition load relay is isn’t operating correctly when the ignition switch is in position 2. So iffy relay due to no 12v supply, or burnt relay contacts not closing if the relay is operating.
Swap the relay with the one next door, or any of the yellow relays as they all have the same pt. no YWB10027L

discool said:

Ok now that clear it appears that the ignition load relay is isn’t operating correctly when the ignition switch is in position 2. So iffy relay due to no 12v supply, or burnt relay contacts not closing if the relay is operating.
Swap the relay with the one next door, or any of the yellow relays as they all have the same pt. no YWB10027L

Click to expand...

sierrafery said:

So, to be clear, when you bridge that relay which you think it's ignition load the blower starts directly or you have to switch it on? also what colour wires it has on the contact sides?

Click to expand...

Hi guys,
I have now resolved the problem, since the mirrors have no relay circuit, I used their feed wire to trace the problem, when I checked the continuity between the fuse port for mirrors and the ignition feed there was no connection which led me to believe there was a connection issue inside the fusebox. So I disconnected it and pulled the box apart to have a look, then realised there was another pin next to where the white feed wire plugs into the fusebox, checked the continuity to the mirror fuse and it showed a connection, I'd found the issue! Turns out when I unplugged the ignition wires from the fusebox to wire in a kill switch a while back, I refitted the white wire on the wrong side of the plug meaning it wasn't getting any power to the fusebox, simply switched it round and everything works! I knew it would be something stupid I'd done.
Thanks for all the really helpful advice discool and sierrafery!!

Picture shows where the white wire should have been on the left side of the plug.