As I was doing some work on my car today I noticed that some ground wires in the engine compartment were quite dirty. If I recall electricity while flowing creates a magnetic field thus attracting foreign debris. They are easy enough to get to so I went ahead and cleaned the the locations. One location was located on the front left in front of the horn, while the other was located on the front right in front of the coolant over flow can. To access the one of the right you will need to slide the coolant over flow can up and out of the way. Both groups of ground wire are held in by a 10mm bolt.

Left/Right is given if you are facing the engine compartment

Before Photos
I didn't take a before photo of the group on the right, however you can imagine how bad they were as well.


I took a second to be on the safe side and remove the ground cable from the battery.


I removed the 10mm bolt with a 1/4 drive ratchet and deep will 10mm socket. Then I sprayed some engine degreaser on some paper towels and a old tooth brush. I used the paper towels to clean the area where the wires were grounded. I used the tooth brush to clean the wires and the bolt. Be sure to wipe it dry when done.


Then I reattached the bolt and made sure it was good and tight.


Here is a shot of the wire on the right.


Repeat the process on this side. The only difference will be moving the coolant overflow can out of the way. Reattach the wires and place to coolant overflow can back into its slot on the cruise control bracket.

Here is all the dirty paper towels from the two locations

Now that everything is tightened back up, attach the negative battery cable back to the battery.

You are done.

Impressions.

I started the car and it seemed to idle better. I am not going to swear to this that it did because I am not sure what all components is being grounded at these 2 locations. Nevertheless good grounds are always important, as electric as our cars are it will allow the ECU to receive process and relay inputs and outputs much faster and efficiently.

 

The black crud is just road dust trapped in the dielectric grease they coat the ground with. Make sure you coat the connection again or it will oxidize.

As long as the metal between the connector and the body is clean, it's a solid connection. The outside isn't too important.

 

In between the ground was equally as dirty.

Thanks I will grab some dielectric grease tomorrow. I completely forgot about that.

 

Good deal.

 

I was just looking at those two spots last night after doing the oil change. this makes me want clean it right now. (2:05am)

 

...Like Martha Stewart Eric is...

 

without the prison time?

 

Eh, I use electrical contact cleaner on those parts.

 

This tread helped me to bring my car back to live. It couldn’t be turn on, everything lighted up when I used a key but starter could be activated it acted like it doesn’t get electricity. But I could up and down my windows, AC worked so I understood that the problem didn’t relate to battery. I did the same thing that you did, I used WD 40 to clean wires. And after I finished I tried to start the car again and it worked! So many thanks for sharing! I daily drive my S2k so it’s really important to me that I can use my car.

P.S: For those how are going to do this trick don’t forget to unplug battery before it.

 

No need to disconnect battery for this task.

You'll want to recoat the bare metal connectors with something to prevent oxidation, or you'll have worse problems later on.

I used this:

Clear Electronic Grade Silicone - 2.8 oz Squeeze Tube