Just over 3 years ago, I decided to make my own grounding kit to mimic the oem accessory one. I never really noticed the difference it made until today. While I was replacing all the soft factory vacuum lines with some thick wall silicone lines, I took out my grounding kit because I wanted to clean up the engine bay a bit, and I didn't think the grounds where really doing much, until I tried to crank the car that is. It kinda sounded like a weak battery, but mine is an 16 month old Interstate mt35. The battery still had plenty of juice though. My GReddy turbo timer has the function of displaying the battery voltage, and with the ground wires on it usually displays 14.2v-14.5v. After removing the ground wires and trying to start the car, the battery voltage was at 13.5v. The car started, but the motor spun over a couple times more than it usually did.

So, I put all the ground wires back on, and wallah, it fires right up like normal. Keep in mind that the 9 year old oem starter and alternator are still on the car. Those extra grounds are the reasons why the starter (probably safe to say the alternator as well) are still running as well as they are. I don't know the normal life span of a starter/alternator, but I drive my car 20k a year, so I would've expected to have had to replace them both by now.

I used 4ga copper battery jumper cable wire with gold plated eyelets from a local car stereo shop, and the cable wrapped in black electrical tape to blend into the engine bay. Here is how my car is grounded:

-factory ground point just below the a/c line (passenger side of engine bay) to the bolt hole to the left of the center mounting point for the oem strut tower brace
-from that point to one of the bolts in the center of the intake manifold
-from that point to the bolt on the cylinder head (right in front of #4 fuel injector) where there is normally a tow hook looking bracket located
-from that point to the transmission case
-from that point to the battery negative
-from that point to factory ground point on the driver side of the engine bay, located right in front of the fuse box
*all the grounding points use an existing bolt with a 10mm head*

 

Good info. Any pics of the install?

 

I would be interested in pics as well. Evodan2004 made up some ground wires (3) last year. I currently have 2 of his wires installed & will be installing the 3rd when I do my trans swap.

 

During this test, were ALL the original OEM ground straps in place?

 

I had a grounding wire kit on my VIII for a few years.

Took it off last summer cause I wanted to clean up the engine bay. Made absolutely no difference in idle, charging, starting etc...

 

Yessir. Not sure exactly why the car reacted the way it did, but I put them back on because I don't wanna have to buy a starter just yet.

If anyone is curious how old my evo is, it's an 03 with 134k miles.

I'll take some pics tomorrow of my grounding locations.

 

Okay, let's take a step back here. Are you saying that the turbo timer read 13.5V with the motor running, or with the motor off?

After reconnecting your grounding kit, did the displayed voltage on the turbo timer return to the 14.5V you expected?

Basically, what you are suggesting is that with the grounding kit removed, you are seeing a 0.7V to 1.0V voltage drop as measured by the turbo timer. Now this is problematic for several reasons.

For one, your electrical system's voltage while the motor is running is mostly determined by the voltage regulator. The battery is actually receiving current rather than delivering it (aka charging), so you're not actually measuring the battery voltage here. Are you sure your regulator and alternator are working fine?

Second, it's going to take a rather large amount of current paired with a rather high resistance to cause a 1.0V voltage drop. The ground wires and chassis combined will definitely not have enough resistance to cause that drop.

However, I'm willing to bet that the interfaces between your stock ground wires and the chassis have corroded to a degree, impeding the current flow. Electrical joints degrade over time unless protected by an antioxidant compound such as Noalox (and a generous application of pressure). When you add your grounding kit, it isn't the new wires helping you out so much as the freshly paired electrical connections at the interface points.

Go back and clean your stock grounding points and interfaces with a lightly abrasive brush, re-tighten all of them, and I will bet that you won't see a single difference with your grounding kit.

You don't know the normal lifespan of a starter/alternator, but you know that you would have had to replace them without your grounding kit? There is no reason a grounding kit is going to extend the lifespan of these parts. This is nonsense.

So why do you propose that running wires to all of these grounding points is going to provide a path of less resistance than just running through the chassis? The chassis is a huge chunk of metal, so it's going to conduct electricity much better than any cable attached to it. True, some of these components you mentioned are electrically isolated and need to be grounded anyway, but there just isn't any evidence that the stock grounding setup is insufficient in any way.


Don't waste your money on grounding kits. If you feel the need to do something with your grounding system, your best bet is to service the electrical joints in your stock system.

 

My car came with a grounding kit. It's really thick gauge red wire. It's an 03 with 138k, original starter, alternator all that. The battery is absolute crap and has needed replacing since I bought the car. It's fairly weak starting up, and if I use my radio with my car off it takes about 10 minutes to drain the battery to where my car won't start. My running voltage is around 14.7.

I have no idea how a grounding kit would extend the life of the parts. But I've had no problems. I'll disconnect mine tomorrow afternoon and see of I notice any difference. My guess is that I won't but hey who knows. If I didn't have the kit, however, I probably wouldn't waste my money on it honestly. I feel it's very gimmicky.

 

It's like I said: I took my ground wires off, and it took longer to crank the car. I put them back on, it acts normal again. The 2 factory ground connections that I used aren't corroded, but I'll go back and check for oxidation. I understand that this isn't normal, and I'd like to figure out exactly what happened so it doesn't become a bigger problem down the road. The lifespan of an alternator/starter was purely an assumption on my part because I expected to have to replace them by now because of the car's age/miles and with all the driving that I do. I could very well be wrong about that though.

 

I'm a little surprised that username was still available in Dec 2011.

 

I'm gonna double check to make sure I didn't leave of any factory grounds on or around the transmission. I've had to take it down twice in the past year, so I may have jumped the gun. I was hoping I was onto something, lol.