wiring woes.

[tomrichardson]

i wonder if someone with better wiring skills than me may be able to help.
i'm trying to get to the bottom of the fact that none of my interior lights work, or have done so for the past 4 yrs of ownership.
i have a copy of the fsm, with wiring diagram of the interior light circuits, and also pictures of the connector blocks throughout the truck.
i am gettin power from the dome fuse, through to connector EA1 which is located under the washer bottle.
this is about as far as it goes!!
i have located IE1 and BL1, both under the passenger kick panel. there is no 12v feed at these points.
also, i cannot get continuity between these two plugs, although the diagram says i should be able to.
looking at the wiring diagram there is a point at which 5 wires are joined. where is this joint and is it likely to be a connector of some sort or will the wires be soldered together in the loom??

if i apply power directly to IE1 pin 1 i can get all 3 lights to illuminate in the "on" position, but nothing in the "door" position.

i feel like i'm going round and round in circles and its starting to do my head in. i'm tempted to run a permanent feed to the lights so i can switch them on myself when i open the door!!

any help and ideas greatly appreciated. thanks, Tom.

 

[Chris]

Yeah, your door switches are knackered. Join the club!

Chris

 

[tomrichardson]

i did consider that but i should still get +12v at the lights, and they would work in the on position. they will only come on by using a power probe.
also. if i leave my lights on the drivers side door switch does work then.

 

[Jon Wildsmith]

Does the door open warning light come on on the dash when you have a door open and if you have an OEM swing out wheel carrier (which you may not) does that bring the dash door open light on? That may help pin point where the earth side of the circuit is broken but you clearly have a power supply problem as well!

 

[tomrichardson]

No, the dash warning light doesn't work either. I have no wheel carrier.
I hadnt thought about having an earth fault on that side of things as well.
I will try fault finding that as well. At least i can get power up to the lights with a temp wire.
I really think if i could find the point where the wires join it would prove to be beneficial. That joint feeds the open door warning light, three roof lights and also the key cylinder light.
I tried back feeding the system from both IE1 and BL1 bit with no joy. There was also no continuity between the two connectors.
I'm about flumoxed with it

 

[Chris]

In the spirit of humouring me and eliminating all possible avenues, try taking a door switch out and contact the connector against clean metal. I have tried to follow the diagrams too and never managed to work out the problem in such a simple circuit myself. But when I pulled the door contact and touched it against bare metal, everything worked. Go figure.

There is also a switch in the boot lock somewhere which seems to give perennial problems. it's not a plunger type like the doors, it's associated with the handle. Usually, the rear wiper stops working too. Another simple circuit. There is reportedly an earth in there which seems to be the root of many evils.


Chris

 

[Jon Wildsmith]

When you tested for power at IE1 pin 1 did you test the male side? that's where the power is.

When you tested for continuity between IE1 pin 1 and BL1 pin 4 did you test the male of IE1 and the female of BL1? If you didn't and instead did e.g. male to male then you wouldn't see continuity.

How about if you test for continuity from the male side of IE1 pin 2 to earth with a door other than the drivers open what do you see? Should be continuity, that's the wire that goes off to the doors. Using other than drivers door means we can ignore the diode that is isolating the lights on reminder from the courtesy lights for the drivers door.

If you inject power to female IE1 pin 1 and connect female IE1 pin 2 to earth the lights should come on with a door open and the switch in the door position?

I would be having a really close look at the male side of IE1, pins 1 & 2 for mechanical faults and perhaps experiment with a parallel bypass of the connector for those wires.

 

[frank rabbets]

There is a poor designed earth in the top tailgate which is worth checking. It gave me weird unrelated problems. If you open the tailgate and take the handle and trim off you will find a twin wire with a connector. On mine I had to remove a metal relay box to get better access. This connector is not sealed and water gets in. Mine was badly corroded so I cut it off and soldered on a twin new one then soaked them in waterproof grease. All cured!

This is a job worth doing anyway in case you end up with 3 faults; and a bonus maybe that it cures your probs.

Frank

 

[Chris]

That's the one Frank!

Wish I'd known about that on my white one. Never got the rear wiper going and yet the motor ran fine and there was power.

Chris

 

[tomrichardson]

thanks for the replies.
i definately have a few things to try out now.
i will look at all the door switches just to be sure, and look at the earth in the tail gate. i have read somewhere about broken wires going into the tailgate as well.
i was wondering where the back door courtesy switch was, and was expecting to find a push switch like the doors!!
i was testing between IE1 and BL1 on the loom side of the connectors.

thank you all very much. after 4 hrs with my head in the footwell it was starting to p!$$ me off. i am also happy in the knowledge i'm not the only one with gremlins in the wires.

 

[tomrichardson]

well i just couldn't help it and have been outside trying things out.

thanks Chris for bringing my attention to the door switches.
i have got the n/s/f one working but both rear ones are not functioning

and Jon for his descriptions of what to poke where. it has helped me understand the wiring diagram so much more.
if i power up pin 1 IE1 with the dome in "door" position i can now switch the lights on and off by pressing the front door switches. how the little things in life make you smile!! i bet my neighbours thought i was mad.

i tried putting power into the BL1 pin 4 thinking it might feed via this elusive joint but to no avail.
i really do think this may now be the route of the problem as i have no +12v in the passenger footwell.
if anyone can point me in the direction of this junction i'd really appreciate it.

i have also removed the tailgate trims to find two wires entering the lock assembly. i will test this when i get time later in the week.

at last, there is light at the end of the land cruiser!!

cheers, tom

 

[Chris]

Good news on the switches. You can pull them apart, but they are best just thrown away. The rear ones always seem to be worse. Just so you know, the switches are on a flying lead and if you get behind the trim panel, the first foot or so of the cable unplugs. I might just order new from Mr T and plug them in.

The rear one in the top door does not have a push switch like the side doors; it's allied to the lock. If you don't shut the back door properly, the rear wiper doesn't work. As Frank says, there is some gubbins in the tailgate responsible for all this. I would get all of that gaffered or at least by passed before further diagnosis. it's simple circuitry, but fiendish.

Chris

 

[Jon Wildsmith]

Have you checked the dome fuse / EA1 again in case you accidentally shorted the power while you've been poking connectors?

 

[tomrichardson]

Still have power through the dome fuse. Have just got some wire piercing probes for my power probe so can hopefully power up at different points along the wires to see if theres a break.
Just out of interest does anybody know if the dome fuse powers up anything else? I thought it did the radio/clock but mine still work when fuse out so maybe not.
Thanks for all replies. Cheers, Tom

 

[tomrichardson]

Just a quick update as theres nothing worse than a thread with no conclusion.

I have just spent a good few hours carefully cutting open the loom to expose the wires for better access. I found the elusive joint i was after, about an inch from the bulkhead. Due to some water ingress into the loom, said joint was corroded and the wires had parted company.
So with a small bypass, i now have power into the system and dome lights that light up
I can now concentrate on chasing some of the other issues such as rear door switches and the tail gate earth and switch.
A very big thanks for all help.
Regards, Tom

 

[frank rabbets]

Thanks for the conclusion ! There is only one thing worse than a thread with no conclusion and that is a connector hidden inside a wiring harness.
Any chance of posting a pic of location? If not could you pm me and I'll send my email address. I wonder if said connector was taped over by the Toyota after import alarm fitters??

Thanks
Frank

 

[Jon Wildsmith]

Good to hear you got to the bottom of it Tom and as Frank says a picture and/or more detailed description of where that joint is could help someone looing at this thread later

 

[tomrichardson]

The joint was quite literally about an inch or so before the main harness passes through the rubber bulkhead gromet. Between the rubber gromet and the array of wires coming out of the side of the loom, behind the ABS pump.
there was one wire feeding from the fuse side and three then passing thought the bulkhead. All blue with yellow tracer and a silver spot every 2".
One goes to IE1 pin 1
One goes to BL1 pin 4
One goes to the open door warning light.
The ignition key light circuit is actually tapped into the wire feeding IE1 somewhere behind the heater matrix/aircon unit inside the vehicle. This is where the wiring diagram is somewhat misleading!
The joint in the engine bay had somewhat disintegrated and the wires pulled apart. From what i now gather toyota used a blue tape to cover joints within the loom, then wrapped the whole loom in black tape. I have found a few " blue taped joints" in my travels now!
Also i have cheated a little , in that i couldnt find the wire inside the truck for the door open warning light so left that disconnected. It was seemingly impossible to pull back wires even a couple if inches whilst going through the bulkhead. I have dome lights so am happy.
I will try to post some pics if i can work out how
Cheers, tom

 

[frank rabbets]

Hi Tom
Are they soldered joints or mechanical ?

Thanks
Frank

 

[tomrichardson]

I think they are soldered as i have found no crimps as yet.
I dont think they have anything to do with the alarm fitting by toyota uk. I may be wrong though, as the alarm is my next wiring port of call. Then another stereo.
If you pm me your email i can fwd some photos.