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914World.com _ 914World Garage _ Electrical nightmare

Posted by: edwin Nov 16 2010, 04:56 AM

Hi all
So with 2 days till I had the car booked for roadworth and rego it looks like i may miss out.
Was chasing a no horn fault and looks like the right side headlight motor wiing shorted out on the green wire. I was under the dash when i noticed the huge amount of smoke wafting by the window. pulled the battery line off imediately but well too late for the green link wire between the 2 lights. main wire to the left headlight looks fine.
Any ideas if i should be looking at something in particular before i hook it all back up?
as i had the steering wheel off to test the horn i noticed some weird things with the highbeam/horn switch. looks like there is continuity between the highbeam switch and horn contact. Normal?
still havent fixed the horn and dont want to hook the battery up again till i am certain nothing else will let the magic smoke out.
any insights very much appreciated
Cheers
Edwin

Posted by: Cupomeat Nov 16 2010, 08:56 AM

Ok, I am not near a wiring diagram, but I think a couple of things about this situation;
1. Each headlight and beam (high and low) is a separate run from the fuse block so there should be no Green link wire for the headlights.

2. there should be no link between the horn and the high beams either (except for ground).

Take a good look at this green link wire and the wires for the horn.

I think someone has made a mess there.

Posted by: Spoke Nov 16 2010, 09:15 AM

Can you be more specific about what you were doing? Did you have the fuse panel down?

Wires generally don't short on each other. What shorts is the connectors at the ends.

If insulation of a wire has melted off, then that wire needs to be replaced. Hopefully it didn't burn the insulation on adjacent wires as they would need replaced too.

If a wire needs replacement, there is no need to remove it from the bundle. Just run a new wire in its place.

Got pics of the damage?

Posted by: edwin Nov 16 2010, 02:47 PM

I have the right side headlight and motor our at the moment so there were connectors loose. I did have them taped but must have missed a bit. The wire that burned isn't power for the headlight globe itself but for the motor. The are three wires for the motor, red white and green.
Another thing I noticed when trying to work out what happened is that the left side highbeam and earth have continuity but the right side doesn't.
The problem I have is that the car is right hand drive so the loom has been extended by previous owners so there are lots of joins and taped wires under the dash and fuse box.
At this stage I am wondering if the horn issue is just a dud relay but the headlight bit concerns me that maybe i have another gremlin to sort out while there.
Cheers again fo the help
Edwin

Posted by: kg6dxn Nov 16 2010, 03:09 PM

Copper conducts heat quite well. You wire may be melted in several places along its length. You should inspect the entire harness.

When OFF, both headlamps should have continuity to ground/earth. High and Low beams. It makes a ground path through the lamp filiment.

Posted by: edwin Nov 16 2010, 03:25 PM

Just another quick question how does the horn button complete the circuit to ground I assumed the steering column would be earthed but mine isn't and neither is the one in my parts car.
I'd post pics but there really isn't anything to see just a meter of green wire burned and I have that replaced now. My big concern is I maybe have a crook relay somewhere.
Cheers
Edwin

Posted by: edwin Nov 18 2010, 04:26 AM

Hi guys
just thought i would let you all know i got the car registered today and all is well after a couple of all nighters.
turned out to be 2 simple shorts and a really "good" quality alarm. replaced the wires to the front trunk and then disconnected the enging imobaliser circuit and all good.
thanks heaps for your time and help.
i'll post some pics after a catch up sleep.
Edwin