Fried Ground...Need Help

[Spoolin98]

I just installed a A/F, boost, and EGT gauge in my car. When i started the car up everything seemed to be working fine. I took the car for a ride to the gas station up the street and while pumping gas i noticed smoke coming out from under my hood. So i pop the hood and notice the ground going from the intake manifold to the body of the car is fried, it melted the coating right off the wire. All the wires installed are fine though. Is this some kind of freak accident? Any ideas on what could have caused this? Or what could solve this? By the way, i tapped into the fuse box for a power source(any advice on where to tap in exactly?), and at the time this happened the A/F wire coming from the gauge was tapped into the wrong wire on the 02 sensor. I didnt realize i didnt have to run the wire into the engine bay i could have just ran it to the ECU. Just trying to give you guys all the facts, sorry for the long post. Any advice or comments are welcome. Thanks

 

[spoolin27awd]

check the connections on that ground also you might have a ground strap off some where else on the engine to the body most cars have more than one of these if one comes off than it sometimes overload the the other wire also check your starter ground to the battery it will also cause that when you crank your car

 

[Spoolin98]

check the connections on that ground also you might have a ground strap off some where else on the engine to the body most cars have more than one of these if one comes off than it sometimes overload the the other wire also check your starter ground to the battery it will also cause that when you crank your car

For some reason i think the last time i was under my car i noticed the ground on the starter wasnt connected, could that cause it? Also, the negative battery terminal is giving me problems, i have to get a new one, im not getting a constant connection. The ground thats not connected to the starter has been off for months, what would make it start acting wierd now? Thanks

 

[luv2rallye]

Yes that is your problem. The heavy gauge wire from battery negative to the starter bolt MUST be good and connected tight. This is the main negative return for all engine electrical. Otherwise it ends up going thru whatever smaller wire exists to the body (and then body to battery negative) which is not big enough for that much current.

 

[Spoolin98]

Yes that is your problem. The heavy gauge wire from battery negative to the starter bolt MUST be good and connected tight. This is the main negative return for all engine electrical. Otherwise it ends up going thru whatever smaller wire exists to the body (and then body to battery negative) which is not big enough for that much current.

I was thinking the same thing, but why would it happen now? I have been driving the car like that for months, then i install these gauges and now it fries a ground. Does that sound correct? Thanks

 

[luv2rallye]

No obviously it's not correct. You may have caused a short somewhere during installation of your gauges. Disconnect all wires to the gauges you installed and see if the excessive current draw disappears. Also do you have this problem when car is turned off, on but engine not running, engine running, or all of the above? If a short is suspect, see http://www.dsmtuners.com/forums/showthread.php?t=179481

 

[Spoolin98]

No obviously it's not correct. You may have caused a short somewhere during installation of your gauges. Disconnect all wires to the gauges you installed and see if the excessive current draw disappears. Also do you have this problem when car is turned off, on but engine not running, engine running, or all of the above? If a short is suspect, see http://www.dsmtuners.com/forums/showthread.php?t=179481

Well as of right now i cant answer any of your questions. When i fried the ground it was when i was cranking the motor, it fried while trying to start the car. I checked the ground off the starter and it wasnt hooked up, so i dropped the starter and put a new one in. The old one wasnt installed tight enough before so it rattled around in the engine bay and the solenoid started to crack. So i installed the new starter right and grounded it under one of the bolts that hold the starter to the tranny. Before i friend the ground, we had the car running for awhile and the gauges worked perfectly fine, then i drove the car to the gas station (5mins) and shut it off, went to start it after pumping and fried the ground. Now im in the process of moving the battery to the trunk, after im done installing it, and i start the car, ill get back to you and let you know what happened. I also put a new ground where the burnt one was and a switch and fuse for my gauges, just to be safe. I also moved the power source from the fuse box directly to the battery. By the way, the negative terminal wasnt connecting tight to the battery, so the battery wasnt recharging while the car was running. When i tried starting it at the gas station, the battery was dead and the ground fried. I had to jump it to get it home.

 

[luv2rallye]

When i fried the ground it was when i was cranking the motor, it fried while trying to start the car. I checked the ground off the starter and it wasnt hooked up...

This I guarantee was the problem. All that high starter current MUST have it's own 4 gauge cable going DIRECTLY to battery negative.

So i installed the new starter right and grounded it under one of the bolts that hold the starter to the tranny.

Yes

Now im in the process of moving the battery to the trunk...

Make sure you follow http://www.dsmtuners.com/forums/showthread.php?t=147017 or http://www.dsmtuners.com/forums/showthread.php?t=98160.

 

[Spoolin98]

This I guarantee was the problem. All that high starter current MUST have it's own 4 gauge cable going DIRECTLY to battery negative. Yes Make sure you follow http://www.dsmtuners.com/forums/showthread.php?t=147017 or http://www.dsmtuners.com/forums/showthread.php?t=98160.

Thanks for your help man. Those walkthroughs are hard to understand though. The walkthrough for the 2g, is what its saying that i can put 2 of the white wires coming from the fuse box together into one spot on the distribution block? and do the same for the other 2 white wires in another spot, and use 60 amp fuses for both? The other walkthrough the guy says he uses different amp fuses for each thing, im just alil confused. My plan as of now is to get a inline ANL 200amp fuse and mount it like 2 feet from the postive terminal on the battery. Then take that line into the distribution block, and out the other 4 gauge spot thats not fused, put the starter wire. Then get 2 60amp fuses and put the 4 white wires coming from the fuse box into 2 of the 8gauge outputs on the block, 2 wires in each, using 60 amp fuses. sound ok? also, i am running power to my gauges off the block, i have a 10amp inline fuse on the wire already, does it matter where i tap power off the block at? If so, should i tap off a non fused port, a 60amp port, or one of the remaining 2 20amp ports i have. Right now all 4 fuses are 20 amp in the block, i need to find 2 60 amp fuses. Thanks again, appreciate your time and help. Also one guy says a 150amp ANL fuse for the battery and the other says 200amp, which one?

 

[Spoolin98]

I did some research looking for ANL style fuses, streetwires sells a ANL type fuse but smaller called AFS, which has fuses up to 150 amps, that should work fine right? By the way, from the research i did, i believe a 200amp fuse is too much for a 2 gauge wire, the wire will burn up before the gauge. 150 is what i read to go with.

 

[luv2rallye]

ok - lots of questions but it sounds like you've got it pretty much figured out. Some points:

1) I have never done the battery relocation to the rear. I gave you those links because I found them hoping they would be of help.

2) Even though I have not done the relocation, I am an electrical engineer of 30 yrs and been working on cars (and car electrical systems) for 40 yrs. So I do have some expertise and experience.

3) Notice that 9d2TSi is doing a 1g ('92 TSi) where koolade9 is doing a 2g ('99 GSX).

4) Both setups will work but I have some comments. I like 9d2TSi having a disconnect switch back at the battery. This is very convenient for working on electrical problems/installations especially when the battery is so far away from the engine/fusebox which can sometimes be a pain to find shorts, etc. (I think it's also mandatory for racing/rallying when battery is in rear).

5) I don't care for his battery negative going to the frame however. Starters draw 100A (and even can have a 200A initial turn-on spike). Going to the frame means you MUST then have a 4 gauge cable from the frame to the starter casing and it must always be a perfect connection. If it ever gets loose or corroded, all that current will find some other way to return from the starter - ie. through some smaller wire from the body/frame to the engine - melt time. Or you may have just created a nice unintentional welder. At bare minimum you have more connection points than with a single cable (every connection point adds some small resistance (which is significant at 100A) and possible future problems). Koolade9 has the battery negative going thru it's own 4 gauge cable to the starter casing first and then to the body/frame which in my opinion is the better way.

6) Koolade9 has a good point about radio ground loop noise to consider.

7) Make sure all your loads are distributed thru the fuses - not too much thru any one.

7) Do you have the manual? I have the '99 Mitsu Eclipse manual and could email you pics of the power distribution system so you can see what loads are put on what fuses if you like. Just pm me your email address if you want them.

 

[Spoolin98]

ok - lots of questions but it sounds like you've got it pretty much figured out. Some points:

1) I have never done the battery relocation to the rear. I gave you those links because I found them hoping they would be of help.

2) Even though I have not done the relocation, I am an electrical engineer of 30 yrs and been working on cars (and car electrical systems) for 40 yrs. So I do have some expertise and experience.

3) Notice that 9d2TSi is doing a 1g ('92 TSi) where koolade9 is doing a 2g ('99 GSX).

4) Both setups will work but I have some comments. I like 9d2TSi having a disconnect switch back at the battery. This is very convenient for working on electrical problems/installations especially when the battery is so far away from the engine/fusebox which can sometimes be a pain to find shorts, etc. (I think it's also mandatory for racing/rallying when battery is in rear).

5) I don't care for his battery negative going to the frame however. Starters draw 100A (and even can have a 200A initial turn-on spike). Going to the frame means you MUST then have a 4 gauge cable from the frame to the starter casing and it must always be a perfect connection. If it ever gets loose or corroded, all that current will find some other way to return from the starter - ie. through some smaller wire from the body/frame to the engine - melt time. Or you may have just created a nice unintentional welder. At bare minimum you have more connection points than with a single cable (every connection point adds some small resistance (which is significant at 100A) and possible future problems). Koolade9 has the battery negative going thru it's own 4 gauge cable to the starter casing first and then to the body/frame which in my opinion is the better way.

6) Koolade9 has a good point about radio ground loop noise to consider.

7) Make sure all your loads are distributed thru the fuses - not too much thru any one.

7) Do you have the manual? I have the '99 Mitsu Eclipse manual and could email you pics of the power distribution system so you can see what loads are put on what fuses if you like. Just pm me your email address if you want them.

I have the battery grounded in the trunk and the starter grounded to the frame with the stock ground, is what your saying is thats bad? I just ordered a 150amp circuit breaker for my 12v wire and 60amp fuses for my distribution block for the 4 white wires going to the fuse box from the distribution block. Im am following Koolade9's 2g installation guide. Does all this seem ok?

 

[luv2rallye]

Ya that's ok. Just make sure you have a 4 gauge or larger (smaller gauge number) cable from the battery negative to the frame (not the body) using a large copper ring terminal and large bolt. Use as much surface area of the terminal to contact the frame as possible and scrape paint off down to the metal where it contacts the frame (don't rely only on the bolt for contact). Tighten securely. Under the hood same thing - 4 gauge or larger from frame (not body) to starter casing bolt.

As for the positive (+12v), make sure to do as koolade9 says "You’ll run the main lead into this block, and then run the lead from the starter, into one of the side ports of it, not through a fused end." It's important to NOT run the starter positive thru a fuse (it's never fused on any cars). This is because it can draw such a wide range of current depending on load, temp, battery condition, wire resistance and connections, etc. that it will blow any fuse you use (also any other devices on that circuit would then have too big a fuse to protect them). A typical starter range is between 60 - 120A. It has it's own solenoid for protection and your 150A fuse back at the battery.

You might want to run two 10 gauge wires from the battery area up to the dash just in case you have radio ground loop noise (leave them unconnected till you need them) - as long as you're tarring up carpet and stuff - you never know what you might need them for.
Good luck.

 

[Spoolin98]

Ya that's ok. Just make sure you have a 4 gauge or larger (smaller gauge number) cable from the battery negative to the frame (not the body) using a large copper ring terminal and large bolt. Use as much surface area of the terminal to contact the frame as possible and scrape paint off down to the metal where it contacts the frame (don't rely only on the bolt for contact). Tighten securely. Under the hood same thing - 4 gauge or larger from frame (not body) to starter casing bolt.

As for the positive (+12v), make sure to do as koolade9 says "You’ll run the main lead into this block, and then run the lead from the starter, into one of the side ports of it, not through a fused end." It's important to NOT run the starter positive thru a fuse (it's never fused on any cars). This is because it can draw such a wide range of current depending on load, temp, battery condition, wire resistance and connections, etc. that it will blow any fuse you use (also any other devices on that circuit would then have too big a fuse to protect them). A typical starter range is between 60 - 120A. It has it's own solenoid for protection and your 150A fuse back at the battery.

You might want to run two 10 gauge wires from the battery area up to the dash just in case you have radio ground loop noise (leave them unconnected till you need them) - as long as you're tarring up carpet and stuff - you never know what you might need them for.
Good luck.

Your the man, thanks for your help. Now i just have to wait for the circuit breaker and fuses to come to finish the job. Ill keep you posted on whats going on. Thanks again, by the way, not too worried about stereo noise, i dont listen to it, i listen to my car

 

[Spoolin98]

Update: I didnt install the circuit breaker yet but i did finish the rest of the install. I used 20amp fuses for the 4 white wires going to the fuse box. They worked fine while idling, i havent drove the car yet. Overall, everything seems to be working well, including my gauges. No burnt ground so far.

 

[94TalonEs]

Does anyone happen to know where all of the grounds are supposed to be on a 94 non turbo? My car has horrible ground, and I've tried everything I can think of to fix it.
Jason