IN over 20 years as a mechanic in both the automotive and construction equipment, I have replaced many damaged components from overheating starter-motors, over cranking to staters, relays reversing switches on winches.
Have seen copper jumper cables which turn a black color inside without melting the insulation yet when you bend the cable which seemed brittle and turn a bright dull orange. On a couple of occasions. Bakelite got so hot from heat it cracked and warped relay and solenoid housings without fire.
One of the worst cases was a international diesel truck with two batteries connected in parallel with so many conections in between the battery cables, wiring, other multiple connections more wire ignition switch intermediate relay and the final solenoid the stater. If every connection on the system had the supposed ⅟10 /one tenth per connection in 8 connection you would have .8 volt less than whats supposed to be a acceptable level.
Any one knows what is the case when as DC starter motor starts overheating and how that may effect current draw.
Back in the mid '80s I had access to a 40K dollar SUN ocilloscpe computer that had the capibity to figuure the compression electrically on each cylinder and other odd problems.
Jeff Verive, BSEE/MSCSE Electrical Engineering & Computer Science, Illinois Institute of Technology Chicago - Illinois T...
Answered May 2, 2017
Originally Answered: Does a splice of a wire have an effect on voltage?
Certainly, though the effect depends on the “quality” of the splice. Voltage drop in a conductor is equal to the resistance of the conductor multiplied by the current running through it. If I cut a wire in two pieces and then casually touch one cut end to the other I will have a higher resistance (and therefore a greater voltage drop) than if I squeeze the two ends together because squeezing increases the contact area, and the resistance is inversely proportional to the contact area (just as the resistance of a conductor is inversely proportional to its cross-sectional area). Indeed, if the effective contact area of the splice is greater than the cross-sectional area of the wire the resulting splice will have a lower resistance (hence a lower voltage drop) than the same length of an unspliced wire.