Electrical gremlins

[elty001]

Had a weird one the other day.
Went out to put some rubbish in the bin and i could hear a buzzing and clicking coming from under the bonnet of the terrano.
Got my keys and popped the bonnet to see what was going on.
This relay was buzzing then the glow plug relay would click.

Also noticed that my twin aftermarket usb charger was lit up and drawing power constantly.
This is fed from the ciggy lighter which is a switched live so shouldn't be drawing any power until the ignition is turned on.
Must have been doing it all night as my start battery was drained.
Obviously a short somewhere.
Did some wire tracing and testing yesterday but still not found the fault.
I've disconnected my second battery and split charge relay to rule that out and also disconnected my aftermarket fuse box and auxiliary lighting.
My next step is to check the switch on the bottom of the ignition barrel as i know these can cause some weird things to happen.
Prior to this i had no warning signs of a problem so it's got me scratching my head a bit

 

[elty001]

Managed to hopefully get this issue sorted:thumb2
The insulation on a live cable had rubbed through and was shorting on the body.
Just want to say thanks for all the help:lol:lol:hide:

 

[Banshee]

Managed to hopefully get this issue sorted:thumb2
The insulation on a live cable had rubbed through and was shorting on the body.
Just want to say thanks for all the help:lol:lol:hide:

That's a pretty obscure one that mate, you did well to push on and diagnose that to be honest, a lot would have given up!!!

Wiring hey!!!!

 

[solarman216]

What was the live cable supplying elt? Rick

 

[elty001]

What was the live cable supplying elt? Rick

Was the live from battery to fuse box on glow plug relay circuit.
There are two white cables that are factory crimped together and bolted to the live battery post.
They come off the battery and join into the loom under the fuse box on the inner wing.
Where they join into the loom the insulation had rubbed through and exposed wire was touching the body.

 

[elty001]

That's a pretty obscure one that mate, you did well to push on and diagnose that to be honest, a lot would have given up!!!

Wiring hey!!!!

I was ready for giving up a few times mate.
Now I've got the fun job of putting everything back in the split tubing.
Also got to drill and tap a couple of hole to re mount the fuse box to the inner wing as both the bolts sheared off when i removed them:doh

 

[Flying Torquewrench]

Just want to say thanks for all the help:lol:lol:hide:

No worries Elty, always happy to help! :roflol::roflol:

Joking aside, well done as electrical faults are always a pain in the backside to find.

 

[elty001]

No worries Elty, always happy to help! :roflol::roflol:

Joking aside, well done as electrical faults are always a pain in the backside to find.

Well my victory was short lived
Thought repairing the insulation on that cable would have solved my ussue.
Found the curcuit by connecting my multi meter in line with the earth to battery and started pulling fuses until i had a significant drop in milli amps.
The effected curcuit is part of the ecm control.
From the fuse box it goes into a multi type relay.
There are two live fused connections to the relay so i removed both the fuses and began to test the pins into the relay.
All good bar one which is pulling 1.5 volts with the fuses pulled.
Traced that wire into the main loom then through the bulkhead into the foot well.
Gave in for today as it's frying my brain:duno:

 

[macabethiel]

Just a thought.

Managed to hopefully get this issue sorted:thumb2
The insulation on a live cable had rubbed through and was shorting on the body.
Just want to say thanks for all the help:lol:lol:hide:

You have an electrical nightmare going on there.

The wire that you found was shorting - are there any immediate upstream (or possibly downstream) relays that may have melted in the closed position whist it was shorting?

 

[elty001]

You have an electrical nightmare going on there.

The wire that you found was shorting - are there any immediate upstream (or possibly downstream) relays that may have melted in the closed position whist it was shorting?

Was my first thought so swapped the relay but made no difference.

 

[solarman216]

Have you tried removing a battery lead and then reconnecting, can you hear a relay if so trace it and identify what it does, also have you tested the amp draw with everything turned off, Rick

 

[elty001]

Have you tried removing a battery lead and then reconnecting, can you hear a relay if so trace it and identify what it does, also have you tested the amp draw with everything turned off, Rick

Amp draw with everything turned off was 99 milli amps which is way too much.
Remove the engine control fuse and it drops down to 16 milli amps.
Have identified the relay as the ecm control.

With the suspect fuse pulled.

 

[elty001]

With the fuse in place and everything turned off.

 

[solarman216]

with fuse in place and relay removed is it the same, Rick

 

[solarman216]

I only have diagrams for up to 98 your 2000 might be similar to Mrs 3 ltr but not sure but I can do some tests once I know what relay it is, the ECU is most likely different though, Rick

 

[elty001]

with fuse in place and relay removed is it the same, Rick

Pulling the relay acts the same as pulling the fuse.
Stops instantly.
It's fine for a few hours then it suddenly starts acting up.

 

[solarman216]

What relay exactly is it? Rick

 

[solarman216]

Sorry I know it is the ECM relay but I need to know where it is so I can locate it on Mrs motor, Rick

 

[elty001]

Sorry I know it is the ECM relay but I need to know where it is so I can locate it on Mrs motor, Rick

It's the 3rd relay from the front of the box in mine.

 

[solarman216]

OK will look on Mrs motor tomorrow, is your 3 the same or am I going up a gum tree, Rick