What would make the jumper cables spark and smoke if you just replaced the trans in a 85 C-10 no problems yesterday but this morning you had no power and you can't jump it because of the cables?

Answer 1

Jump start cables must always be connected

"+" to "+" and " - " to " - "

NEVER the other way around.

Note: It is much safer to connect the last "-" cable to somewhere on the car's bodywork away from the second battery. After the car has been started remove that same cable first. Doing it that way will help to avoid sparks causing explosions of the hydrogen gas which is given off from batteries when they are being charged.

Other answersVERY DANGEROUS!

If connected improperly:

either from "+" of Battery A to "-" of Battery B

or

from "-" of Battery A to "+" of Battery B

then that would cause the jumper cables to short-out both batteries - boy would they spark, smoke and burn!

Because of the physical location of the starter in relation to the bell housing of the transmission, check for a short at the battery connect at the starter. Make sure that those connections are completely clear of any part of the bell housing and transmission. If that was the last place you worked, I would suspect that is the place to start looking.

Could be the cable is too light for the load i.e. excessive current draw for the wiring size.

Could be a dead short somewhere in the vehicle.

Check for a battery cable grounded out on the exhaust manifold.