Why a good ground is important

[squonk 46,340]

Restoring a tractor? Painting an engine? Watch this video on why you need to have clean metal (no paint) for your grounds and how it effects engine cranking, 

 

 

[ri702bill 12,023]

The electric engine fan on our old 1989 Old Cutlass Ciera stopped working. It would always come on when the AC was switched on, but no more. Jump the connector & it works fine....

There was a long threaded stud on the lower front of the engine with about 4 stacked ground wires, a washer & nut. Ahha - it was a fuzzy white color, not shiny metal. disassembled the stack, cleaned both sides of all the lugs & mount, and reassembled. A good smear of dielectric grease over them, ploblem solved... Looks like it was a poor choice in the ground location, open to road splash.

[953 nut 65,716]

Unfortunately many people do not understand that an electrical circuit needs a return path to work. Electrons can't just flow out (potential energy) and do work, they need to go through the device (light, motor, etc.) and back to the battery to do work.

Edited yesterday at 11:05 AM by 953 nut

[oldlineman 1,697]

That is the whole reason for Insulate and Isolate when we work safely on AC circuits. One of the first things we learned as apprentices.  

[pfrederi 20,429]

You can trust your mother not your ground....

[WHX?? 56,425]

2 hours ago, ri702bill said:

it was a fuzzy white color

I've got an a aluminum trailer and the lights always give problems. The lights are grounded to the frame with a self tapping screw and the dissimilar metals corrode the terminal rings. 

Would guess the same thing can happen on aluminum engine blocks. 

[gwest_ca-(File Mod) 12,202]

We had a K10 Chev Blazer come in with a noisy drivetrain. Every bearing in both front and rear axles, U-joints, differentials, transfer case and transmission had failed. Cause was a poor ground between the body and the battery. Current was flowing through the bearings to get to the engine which had a good ground. A very costly repair to a vehicle less than a year old.

 

I should add that the cause was discovered before the damage was found. The technician had the radio on and when he removed one end of a drive shaft the radio quit.

[squonk 46,340]

39 minutes ago, WHX?? said:

I've got an a aluminum trailer and the lights always give problems. The lights are grounded to the frame with a self tapping screw and the dissimilar metals corrode the terminal rings. 

Would guess the same thing can happen on aluminum engine blocks. 

Had a real good one way back in 1980. Olds Omega with a manual trans. Under warranty came in with a broken clutch cable at the bellhousing. so I replaced it. Came back a month later with another broken cable. So I replaced it again. This time it looked like the cable was burnt. Turned out the negative cable at the bellhousing was loose 5 inches away from the cable. When starting an arc jumped between the cables and burned through the clutch cable.

 

I have also seen choke and throttle cables glow on Wheel Horses! 

[Ed Kennell 45,916]

2 hours ago, WHX?? said:

dissimilar metals corrode

I had a new 1970 Jeep Wagoneer that would just shut down while cruising along along at 65.      I found thet it would restart if I disconnected and reconnected a multi pin connector located on top of the radiator.    after several shut downs, I cut out the connector and connected each wire.    Several months later I got a recall from Jeep to get the connector replaced.  Seems the male pins were brass and the female sockets were aluminum.

 

 

 

[Razorback 1,289]

We have a 1981 Ford Bronco. I’m not sure how many model years are plagued by this, but I bet it’s several: the electric rear window is notorious for getting very slowwwwwwwwwwwwwww to go up and down, if at all. Happily, I fixed ours by cleaning up a ground point behind the rear left brake light housing. 

[oldlineman 1,697]

22 hours ago, WHX?? said:

I've got an a aluminum trailer and the lights always give problems. The lights are grounded to the frame with a self tapping screw and the dissimilar metals corrode the terminal rings. 

Would guess the same thing can happen on aluminum engine blocks. 

Probably best fix for this problem is running a common ground from each load point back to the battery (power source). A little more work and cost but eliminates grounding problems. 

[WHX?? 56,425]

1 hour ago, oldlineman said:

running a common ground from each load

If I had to rewire the trailer that is exactly what I would do.