The one going to the starter motor, fuse block, and alternator is positive. The one going to bolts on the engine and frame is negative. VW has black wires going to positive and red going to negative.
When the cables weren’t clearly marked, you USED to be able to trace them back to determine their polarity. If the car was new enough to be negative-ground, the cable you traced back to the engine block was negative. Try that nowadays – I dare you!
Lately, on DC powered equipment, any color for either + or – ! No one follows the standard red +, black -. RV’s are even worse. If you ask for a wiring diagram, if there is one, they are wired by so many different techs they don’t follow the same map or color codes. Talk about frustrating!
Lot of older cars didn’t have colored battery cables. Just trace the cable back and the Negative will be bolted to the frame or other grounding point on the car.
Like someone said, a meter is useful here. If there’s no current flowing, testing for continuity between the chassis and the wire will give you a clue. And if current is flowing, you will know when you get a bright spark that you have the wrong negative wire!
how many other guys can proudly state that they’ve burned up a snowblower? i, oops, slipped with the wrench while trying to unhook the battery and the next thing i knew, my wife was screaming, get the fire extinguisher, you idiot! ☺
Check where the other end is connected, if it’s to the engine block or the car frame it’s negative, also if it’s black it’s probably negative. Red is usually power or positive.
My parents drilled into me, “positive to positive, negative to ground.” I had to insist on jumping to/from my own battery because so many men would forget to ground.
Cactus-Pete over 1 year ago
Those are cables – the red one is positive.
Templo S.U.D. over 1 year ago
You work at an auto parts store, Baldo, and you never learned positive and negative wiring? That’s unbelievable.
fabiocolotta over 1 year ago
The black one
Rhetorical_Question over 1 year ago
Try a Youtube Tutorial?
Rhetorical_Question over 1 year ago
Are they installing a battery?
Kidon Ha-Shomer over 1 year ago
And this is the lad who will ‘restore’ a 64 Chevy by himself?
PoodleGroomer over 1 year ago
The one going to the starter motor, fuse block, and alternator is positive. The one going to bolts on the engine and frame is negative. VW has black wires going to positive and red going to negative.
sheilag over 1 year ago
The multimeter is your best friend when it comes to automotive electrics…
I’ve seen people assume red = positive, black = negative but the previous owner installed cables using the opposite colors.
The Orange Mailman over 1 year ago
At least he is thinking positively.
Droptma Styx over 1 year ago
When the cables weren’t clearly marked, you USED to be able to trace them back to determine their polarity. If the car was new enough to be negative-ground, the cable you traced back to the engine block was negative. Try that nowadays – I dare you!
Snolep over 1 year ago
You’ve gotta accentuate the positive.
MuddyUSA Premium Member over 1 year ago
Better positive than negative.
rbullfogg over 1 year ago
Lately, on DC powered equipment, any color for either + or – ! No one follows the standard red +, black -. RV’s are even worse. If you ask for a wiring diagram, if there is one, they are wired by so many different techs they don’t follow the same map or color codes. Talk about frustrating!
BeniHanna6 Premium Member over 1 year ago
Lot of older cars didn’t have colored battery cables. Just trace the cable back and the Negative will be bolted to the frame or other grounding point on the car.
WestofthePecan Premium Member over 1 year ago
Like someone said, a meter is useful here. If there’s no current flowing, testing for continuity between the chassis and the wire will give you a clue. And if current is flowing, you will know when you get a bright spark that you have the wrong negative wire!
gopher gofer over 1 year ago
how many other guys can proudly state that they’ve burned up a snowblower? i, oops, slipped with the wrench while trying to unhook the battery and the next thing i knew, my wife was screaming, get the fire extinguisher, you idiot! ☺
Sailor46 USN 65-95 over 1 year ago
Check where the other end is connected, if it’s to the engine block or the car frame it’s negative, also if it’s black it’s probably negative. Red is usually power or positive.
emiesty Premium Member over 1 year ago
My parents drilled into me, “positive to positive, negative to ground.” I had to insist on jumping to/from my own battery because so many men would forget to ground.