Technical Fried distributor y block

Any insight on why my wire melted from coil to dist.? Heres the background so blew the motor in my 64 f250 (292 y block) tracked down new motor came from 58 or 59 ford car possibly fairlane or country squire swapped my parts over to make it mountable in the truck (oil pan and pickup tube timing cover and water pump exhaust manifolds alternator brackets((gm one wire)) intake manifold) using all my parts on the new motor like coil and starter and solenoid new cap rotor plugs wires after everything was hooked up I dropped in a battery and went to crank it after about 10 seconds of cranking I noticed some smoke got out to check and noticed I'd melted a wire so I'm wondering does anyone have any idea what would have caused it? From my searching there's no real difference in the distributors and all my wiring is exactly the same as when I pulled the old motor hell most of the parts are the same ones could it be a bad ground from the block? I still have my old distributor from the 64 block but would like to figure out any issue before swapping it in and melting it too. Thanks in advance -Mike.

 

the time I did that was when I hot wired an engine to start it, and accidentally clipped the hot wire on the negative coil terminal (which goes to the points), instead of the positive terminal.

But we'd probably need to know more about the wiring in the car to be able to help you figure it out.

 

PM GMC_BUBBA, he is the Dizzy Master....

 

Ill take some pictures this afternoon and post them so you can see what I have going on .

 

Got points ? Probably lack of a ballist resistor ?

Oldmics

 

Its still points maybe ill go buy an internal ballast coil for the 58 fairlane I believe my old one was external. I was assuming it was somehow voltage related as I know too high or too low voltage will melt a points eliminator

 

External ballist is kosher to use.
Just make sure that the "run" voltage is filtered thru it to reduce the current.

Oldmics

 

Still should not fry the wire.

 

The ballast resistor should be bypassed when the ignition switch is in the crank position.

 

Yeah, it will .Ask me how I know !

Also check that the internals on the fried distributor were wired correctly.

Oldmics

 

I guess it might depend on the coil, and how thick the wire is.

 

That was my thought as well.

Measure the primary winding resistance (ohms) - between the coil terminals, if you don't know what it is offhand.

Report back what it is.

 

I've had the wire short out where it passes thru the distributor body. It didn't melt; but found it was getting pretty hot while checking for loss of spark on the side of road.

 

That's the thing, the wire will let a certain amount of current go through it, and not get hot enough to melt the insulation. The amount of current it sees is limited by the resistance of the coil, and the ballast resistor (if there is one). Ohm's law will let you figure out the current, based on voltage and resistance. There are tables where you can look up the current capacity of different wire sizes, which is usually based on the temperature that the insulation is allowed to get up to.

It's all pretty complicated, if you're an engineer.

 

I was going to say the same thing. Many years ago I was hot wiring a car and clipped the jumper to the neg side of the coil. Let the smoke out I did.

I guess a careful look over is warranted.

 

So here's a few pics the ones out of the motor are of the 58/9 that was in that fried the last pic of the one in the motor are of my original 64 I went ahead and swapped it in already the difference being the single wire instead of a jumper wire looking at it out of the truck it appears to be a later style or a replacent only a guess bybthe stamping saying motorcraft instead of ford so I'm gonna wire up my 64 with a new coil I had in the glove box

 

hard to tell how the coil was wired, from your pics...

The tag says C5... which means 1965 or later.

 

It got to be the coil even a dead short in the distributor would not fry the wire closed points are a dead short. The only other choice is way more than 12v going to the coil.

 

Look at the wire on the condensor. It may be shorted to the distributor body.

Yes, that would fry the wire if any of them are going to dead short. If the points are closed with key on and not running... Can do it too.

Sent from my Moto G Play using The H.A.M.B. mobile app

 

Well not too sure what it was but with the 64 dist. And new coil it fired I just have to adjust timing. My only guess is it had something to do with that bridge wire on the 58/9 (decoded as 65-or later) dist. I pulled but here's a pic of how its all wired .

 

From what I've looked at on the problem dist. Is a little bit of surface rust on the condenser and a crack in the ground so possibly a combination of little things caused it to short

 

That was my original thought that maybe it was an earlier one and possibly only 6 volt but as someone else pointed out its a 65 or later dist.

 

Question 1- 65 or later Y block?? question 2 what does the green wire in the picture go to Tach?

 

I'm with Sunbeam, last year for the Y block was 64, and those distributors do not fit anything else.

 

64 was the last year for Y Blocks, at least domestically.

 

Check engine ground........................................................

 

64 last year and yes tach is green wire .

 

So my truck is 64 the motor date stamps 58 the distributor another member mentioned to be 65 or later and another had mentioned something like up to 78? Body's were the same but different length shaft but ive got the 64 dist. In it now and got it to fire still would like to determine what the issue might have been for future references but as mentioned above a short in the dist. Was the likely cause .

 

The C5 could designate a service replacement....

 

Yes, it could.