LD1989

Member

• Feb 15, 2020

• #1

So driving home last night I had black smoke coming out of the dash. I pulled over hit the isolator switch and grabbed extinguisher. The smoke had already diminished luckily.

Looks like the red cable that goes into the illumination switch was the one that went up. Melted a few other bits of insulation. But mainly just that wire fried - don't know why it would've drawn so much current?

Does anyone have any ideas of good starting points to find possible causes. I've been working on some ground problems (lights dimming and wipers slowing) as well as removing bloody scotchlocks and sorting bodged wiring for a while. I could have disturbed some brittle wires maybe?

Checked the fuses and all ok. But the side lights have 50 amp fuses in. I never even thought to check what was actually in there.

I'd appreciate any help. I'm off to get some blue sea fuse boxes and will switch to spade while I'm repairing.

 

R

rob1miles

Well-Known Member

• Feb 15, 2020

• #2

Usually worn through insulation at a sharp edge or a failed bulb that has melted to earth. Check the bulbs first then disconnect each light circuit where they branch and find the one with the short. Go back over everything you touched recently. I spent weeks looking for an intermittent short - the car had been in a garage for some repair work and they had noticed a clip on the fuel line underneath was loose so the put a new self tapper in. OEM one was short and blunt, they put a longer pointed one in and right above it inside the footwell was the wiring harness. They never told me so I spent hours searching for the fault.

 

LD1989

Member

• Feb 15, 2020

• #3

Thanks for the advice. There hasn't been much damage luckily. Been to get a new master light switch and checking through the loom. I have headlights ungrounded and side bulbs removed but am getting continuity between the load sides of the headlights and side light fuse connections. Only with the fuses in. Master light switch is disconnected. Continuity between them shouldn't exist in these circumstances? I might be being dumb as I have wire blindness now and am checking eBay for ford bloody rangers

 

payydg

Well-Known Member

• Feb 17, 2020

• #4

How old is the vehicle? Happened to my fathers series the other week.

The only way to have complete piece of mind is new wiring loom but you can pick up a lot of potential issues by inspecting all the connectors, making safe the inevitable bodges and renewing as you go

 

LD1989

Member

• Feb 17, 2020

• #5

payydg said:

How old is the vehicle? Happened to my fathers series the other week.

The only way to have complete piece of mind is new wiring loom but you can pick up a lot of potential issues by inspecting all the connectors, making safe the inevitable bodges and renewing as you go

Click to expand...

It's a 1989 90. Think I'm going to rebuild the light looms and add relays and inline fuses. The engine bay loom is spot on and the main loom is good. I've removed a lot of what I don't need like rear window bits and accessories. So I can have a basic solid loom

 

Hippo

Lord Hippo

• Feb 17, 2020

• #6

If yer cables are carrying enough current to get hot enough to burn the cable insulation to create smoke then yer fuses are rated far too high. The first job of a fuse is to protect the weakest part of the circuit, which is the cable. Yer need to fit lower rated fuses suitable for protecting the cable. Not unusual for owners to fit what they have to hand as a replacement even though it's higher rated. They probably would have blown open during the resent "fire" fun if they were lower rated.

 

Stanleysteamer

Well-Known Member

Full Member

• Feb 17, 2020

• #7

Or some g!t has replace a thick wire with a thin one and it is acting like a fuse. We've often seen it.

 

LD1989

Member

• Feb 17, 2020

• #8

Thanks for all the advice. The extent of the damage is basically just the red and white cable from the illumination switch to instruments melting and the red coming from the master light switch started to follow.

https://ibb.co/VBFfMK6

I couldn't attach an image on my phone.

Getting a lift to work in an L200 at the moment and those buggers dont even wave at each other!

 

nobber

Well-Known Member

• Feb 17, 2020

• #9

Get a wiring diagram, in the older vehicles not everything was fused, my guess is resistance through a bad connection caused the wire to have too many amps drawn through it and melted it, if the 50 amp fuses fused that circuit obviously an 8 amp wire will melt before the fuse blows, either that or something else was drawing power through it.