Cleaning up electrical ground connections

[Snagglefoot]

Here is a photo of the ground wire underneath the driver’s side door on a GMT-900 truck. The motor to actuate the transfer case is grounded here. I’m planning on cleaning this up then spraying it with a rust resistant spray. From what I read, a bad ground here is one of the reasons you can get a “Service 4WD” light. Anyone else have some “ bad ground” tales?

 

[JHZR2]

So you are getting those warnings/codes?

that doesn’t look like a bad ground necessarily. Dirty, rusty, yeah.... but have you tested continuity with a meter?

Not saying it’s a bad idea - seems like a simple enough spot to get to and fix... but do you know it’s bad?

 

[Snagglefoot]

So you are getting those warnings/codes?

that doesn’t look like a bad ground necessarily. Dirty, rusty, yeah.... but have you tested continuity with a meter?

Not saying it’s a bad idea - seems like a simple enough spot to get to and fix... but do you know it’s bad?

Just a momentary light up once in a while. Enough to make me wonder about the ground. The motor, the front axle actuator and the control knob are the items up the expense ladder. Right now it functions fine.

 

[JHZR2]

Seems like a good PM. Let us know how it works out!

 

[atikovi]

Here is a photo of the ground wire underneath the driver’s side door on a GMT-900 truck.

View attachment 39992

Can't go by just what you see. Its what's under the head of the bolt and what's between the wire and frame that counts.

 

[Kira]

1) Grounded electronics were mounted on the painted firewalls during my servitude at a dealership.
Mechanics wheeling paint away, then remounting everything, was common.
Of course this wasn't done pre-sale. My boss worked with the warranty time frame.
He was dog's dirt extruded from a cookie press; cheerful with icing and sprinkles but still dog's dirt.

2) I cleaned up and sold a 2001 Camaro for neighbors. Green corrosion in the body's bulb sockets predominated.
Replacement bulbs, diligent cleaning and lens sealing worked.
Two "Camaro Refreshers", brothers who owned a shipping container packed with salvaged Camaro parts, came by.
The "alpha bro" exclaimed, "Hey, all the outside lights work". Good grounds sold that car.

 

[buck91]

I try to hit my grounds with rust prevention (T9 or HDMP on the under side, FF when less exposed) whenever I'm doing other PM and notice them...

 

[willbur]

So you are getting those warnings/codes?

that doesn’t look like a bad ground necessarily. Dirty, rusty, yeah.... but have you tested continuity with a meter?

Not saying it’s a bad idea - seems like a simple enough spot to get to and fix... but do you know it’s bad?

Do voltage drop under load. To prevent corrosion and enhance conductivity, I use copper antiseize under the lug.

 

[Snagglefoot]

Do voltage drop under load. To prevent corrosion and enhance conductivity, I use copper antiseize under the lug.

That’s the magic I need. I just purchased this.

 

[atikovi]

That’s the magic I need. I just purchased this.

View attachment 40022

Isn't that going to insulate and cause high resistance?

 

[Snagglefoot]

Isn't that going to insulate and cause high resistance?

Permatex says it has good electrical conductivity.

 

[atikovi]

OK, personally I'd want a product specifically made for electrical connections like https://www.sanchem.com/electrical-contact-lubricant.html

 

[willbur]

Isn't that going to insulate and cause high resistance?

Atikovi-
Actually, a small tube/packet of copper antiseize is typically included with O2 sensors. These things deal with tiny/small voltages and any additional resistance causing voltage drop would constitute a significant portion of the sensors output, setting a CEL. So, copper AZ prevents corrosion and thread seizing for easy removal, decreases resistivity, and protects the connection. Copper is a much better conductor than steel on steel. I use it on all grounds. Cheap, too

Regarding that special sauce- to each his own...

 

[Snagglefoot]

Got it done. The bolt came out easy. I cleaned up the surface with brake cleaner, put a dab of copper anti-seize on it, coated the bolt with it, and screwed the bolt holding the plate back on. There was no paint underneath nor was it rusty. The interesting thing is that there is a nut welded to the sheet metal on the other side, so if you see one that is seized, put a wrench on the back side before you do put the torque to it. Just another thing to check off. Thanks for the interest.

 

[atikovi]

Atikovi-
Actually, a small tube/packet of copper antiseize is typically included with O2 sensors. These things deal with tiny/small voltages and any additional resistance causing voltage drop would constitute a significant portion of the sensors output, setting a CEL. So, copper AZ prevents corrosion and thread seizing for easy removal, decreases resistivity, and protects the connection. Copper is a much better conductor than steel on steel. I use it on all grounds. Cheap, too

Regarding that special sauce- to each his own...

Umm, you put that on the threads, not the electrical connector.

 

[ChiTDI]

I have used Deoxit D5 for a long time on grounds. Seems to work.
Any products known to be better? D5 was state of the art turn of the millennium.

 

[willbur]

Umm, you put that on the threads, not the electrical connector.

Umm, I know that! LOL
The connection is between the O2 sensor threads and the engine ex. manifold, not on the wire leads.

 

[willbur]

I have used Deoxit D5 for a long time on grounds. Seems to work.
Any products known to be better? D5 was state of the art turn of the millennium.

I use that Deoxit stuff a lot. Works good, too. But I don't think Deoxit would last more than a min. on O2 sensor threads, while that AZ can tolerate 1500 F for years(?). For wire to wire connections Deoxit is great but ,in MO, not for exposure to harsh environments

 

[atikovi]

Umm, I know that! LOL
The connection is between the O2 sensor threads and the engine ex. manifold, not on the wire leads.

Are there any cars made in the last 20 or 30 years that use a single wire sensor where that would even apply?

 

[willbur]

Umm, I know that! LOL. The connection

Are there any cars made in the last 20 or 30 years that use a single wire sensor where that would even apply?

Are we in a gotcha mode here?