Burnt Wire

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shittyslant6

shittyslant6

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So, I just made a new positive battery cable going to the starter. (1970 duster slant 6) When I got in and turned the key, nothing happened. Then this wire (picture) burnt all the way through. Form what I can see, this does nothing and it is a ground to itself. If anyone has any explanation on what this wire does or why it burnt it would be greatly appreciated. (wire was white)
IMG_20210218_143424.jpg
IMG_20210218_143427.jpg
 
I'd be looking for what else fried. Did you hook your battery up backwards????????
 
Disclaimer... I’m not an expert, by all means, but I’ve been dealing with mucho electrical problems. What gauge wire did you use for the new battery wire? Is it larger than your battery ground and any other main ground wires? It’s possible that you need to up your ground wire gauge. Hopefully an expert answers as well.
 
John Collins said:
Disclaimer... I’m not an expert, by all means, but I’ve been dealing with mucho electrical problems. What gauge wire did you use for the new battery wire? Is it larger than your battery ground and any other main ground wires? It’s possible that you need to up your ground wire gauge. Hopefully an expert answers as well.
Click to expand...
Yes, I got a new wire from a buddy and it is larger than the original and the ground wire. But why would that burn out that wire to nowhere? Oh, the ammeter gauge went to -40 when I turned the key.
 
Evidence is pointing to a ground short in the column.
If you recall which key position it was in when you pegged the ammeter, then you can narrow it down to two of the four circuits coming out of the key switch.
You're lucky that column grounding wire went first. Saved you from much more serious damage.
 
Clean up all that electric and get stuff - like the fuse box - properly secured. Having stuff swinging around is putting stress on the wires and connections.

1970 is wired basically like this.
upload_2021-2-18_20-10-6.png


Everything connected to the battery positive is hot.
When the key is moved to Start, the circuit to the Starter relay (yellow) and the Ignition 2 wires are completed. (assuming its in neutral or Drive)
The current will flow directly to the relay which in turn connects the starter solenoid. Power also flow through the coil when the point are closed. The ammeter will show this current. its about 2-3 amps.

When the key in Run, that connects the ignition 1 and the key accessory circuits.
 
I think it's the opposite of a short. I think your engine IS NOT GROUNDED to the battery and the body is attempting to be the ground path It might be that the path is shift linkage--column-ground.
EDIT= STUPID MISTAKE
The battery should be grounded direct to the ENGINE with a jumper from either the engine or battery to the body. "This is not always the case" Could even be a corroded ground cable internally

"When I was young" and had the old 70 440-6 car, I had done some work, the battery was in the trunk. I forgot to connect the engine-to-frame jumper. Twisted the key, sparks and noise under the dash AND IT **** THE CLUTCH LINKAGE RETAINER right off the linkage!!!
 
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67Dart273 said:
I think it's the opposite of a short. I think your engine IS NOT GROUNDED to the battery and the body is attempting to be the ground path It might be that the path is shift linkage--column-ground.

The battery should be grounded direct to the battery with a jumper from either the engine or battery to the body. "This is not always the case" Could even be a corroded ground cable internally

"When I was young" and had the old 70 440-6 car, I had done some work, the battery was in the trunk. I forgot to connect the engine-to-frame jumper. Twisted the key, sparks and noise under the dash AND IT **** THE CLUTCH LINKAGE RETAINER right off the linkage!!!
Click to expand...
 
Normally that wire grounds the steering column so that the horn relay will work. But
8=96.jpeg
as noted above I would definitely check your engine ground
 
67Dart273 said:
I think it's the opposite of a short. I think your engine IS NOT GROUNDED to the battery and the body is attempting to be the ground path It might be that the path is shift linkage--column-ground.

The battery should be grounded direct to the battery with a jumper from either the engine or battery to the body. "This is not always the case" Could even be a corroded ground cable internally

"When I was young" and had the old 70 440-6 car, I had done some work, the battery was in the trunk. I forgot to connect the engine-to-frame jumper. Twisted the key, sparks and noise under the dash AND IT **** THE CLUTCH LINKAGE RETAINER right off the linkage!!!
Click to expand...
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I agree. Even if all the ground wires are there, take them off, clean up the connection and put No Ox on it.
 
the horn switch completes the path to ground through the steering column, I would guess amperage arched at the horn switch
 
It may be that.
But that doesn't explain the 40 amp discharge to the key switch.
 
I agree it does not explain the amperage draw at the amp meter. Other wires inside the steering column and or switches could also Arc to the steering column
 
yesterday i dropped the steering column and all of the wires looked perfectly fine. I put a test light to all of the fuses when the key was in the on position and all of them lit the light up except Inst. Lps and Tail lp. As for the ground to the block, It is connected as I have yet to mess with that yet. I will check that it has good ground and clean it as post #12 said. As for the 40 amp discharge, I have zero clue. put the key in on position, (discharge) then turned the key off when I noticed the sizzling noise from under the dash. apparently my dad heard a electrical buzz underneath the hood by the starter but he was not too sure. also, why would the shift linkage be one wire grounded to itself with no other wires going to it?

Could the voltage regulator be bad causing the -40 discharge?
 
Two of the fuses are hot at all times. This includes tail lights, brake lights and dome light.
Two or three are hot when the key closes the 'accessory' circuit. This includes Turn signals and heater.
Instrument lights are a subcircuit fed from the headlight switch.

shittyslant6 said:
Could the voltage regulator be bad causing the -40 discharge?
Click to expand...
A 40 AMPERE discharge with the key off is a short to ground before the key switch.
You need to observe when the ammeter moves, as well as how much and which direction.
Look at where the ammeter is placed in the circuit (see diagram above).
The ammeter shows current flow out of the battery (Discharge), or flow into the battery (charge).
Key off, lights off, there should be no current flowing either way.
 
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So you never turned the key to crank??? .. just to On and it fried? It's not your voltage regulator...
 
To avoid causing additional damage while investigating.
Disconnect the battery positive.
Set the multimeter to measure resistance or continuity.
Connect the meter probes (clamps) with one on the battery circuit.
Then start checking for shorts to ground.
First touch the second probe to the first. Thats what a short will look like. If set to resistance it will show close to zero.
Seperate them and thats what it should show when there is no short.
Next touch the second probe to the body, the steering column, the engine block.

If that all passes.
Then turn the key to run and do it again.
You can recheck the accessory and run circuits too. They should have no resistance.

Finally have someone hold the key in start and check for shorts to ground.
You can also check the connections from the battery line to the S1 (yellow) and the Ign 2 (brown). They should be zero.
...............................
Another way to safely look for why the ammeter is showing a high discharge is to install a lamp in the circuit.
The lamp will reduce the current flowing to a few amps. it will also light up whenever a connection is made.
67Dart273 has posted good descriptions of how to do this. If you're interested do a search for his posts how to do it.
 
dadsbee said:
So you never turned the key to crank??? .. just to On and it fried? It's not your voltage regulator...
Click to expand...
Yes, the discharge happened right when the key was turned to crank with the key on acc., it went back to zero
 
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