bad ground, replacing it, where are all of them? please help

[SoCalGST]

hi, well i know i have a bad gound somewhere in my engine so i went ahead and bought a ralliart ground kit that comes with seven 8 guage wires a new aluminum thing to put on my battery's negative terminal and some little thing i hook all the wires too. Now heres where my problem comes into play. I can't find my ground wires, i checked the make your own ground wires faq, it had nice pictures but all the placs he hooked up his ground wires aren't there in my car. In my enigine bay i can only see 2 ground wires. He has a total of 8 in his faq, and im getting 7. Can someone please enlighten me as to what im supposed to do, and where i need to hook up my wires. thanks in advance.

 

[SoCalGST]

someone please help me, can someone tell me where all the grounds are at in a stock engine and maybe give me some pics... i need help.

 

[luv2rallye]

The car only comes with (and needs) 2 grounds - 1 to firewall, other to block. He is adding more just to improve grounding (so each high current area has it's own ground rather than having to go thru 1 of the 2 other grounds) to improve electrical power transfer (lower the resistance). If you want to do the same, pick some bolts on the same items in your car to connect the ground cables to.

 

[SoCalGST]

well my chilton's wiring diagram shows a lot of grounds at specific locations in my engine bay but i cant find them, so am i missing something? i found the 2 your talking about, so if... those are the only 2, and i know i have a bad ground then replacing them with the 7 im getting should do the trick right?

 

[luv2rallye]

Many of the grounds in your manual are the devices (eg. sensors) or units (eg. ECU) that are bolted to the engine or the body. Thus their cases are electrically connected to battery negative which is called ground (thus eliminating another return wire for each). Most manuals show a grounding type symbol for these. But there is only 2 factory cables that go to the battery negative which is also called ground. One from the body and one from the engine block.

There are also many harness connections to the engine and the body which are also called grounds (so the current can rtn to the battery negative thru those 2 battery cables). Perhaps this is what you're refering to. They are hard to find/see but if you really need to know, PM me with an email address and I'll send you the manual pics of them.

You can always add more wires from any "grounding point" to battery negative (or to another grounding point) if you think one is broken or you just want to distribute the current thru more than one wire (to reduce voltage drop which is what the ground wires faq is about). But if one of the harness ground connections is broken/missing, you are going to have to find and fix it since it is the rtn path for the devices on that harness.

 

[SoCalGST]

thank you so much, thats exactly what i needed to find out.

now i have more question, il ltell you my problem and maybe you can tell me if this sounds like a bad ground.

about 3 or 4 months ago i noticed a decreae in the power of my car, my headlights dimmed significantly, nad when i turned on my lights, i noticed my stock stereo went extremely dim, when my blinkers are on my tach blinks light, and dark, timed to the blinker. if i try and roll up both windows at the same time, i feel the car shake and struggle. well i had my battery tested and it came up 12 volts, my alternator came up at charging 14.7-14.9 volts. so i just recetly tried turning my a/c on, it was hot, so i tried filling it with r134a it didnt take it, so i took it to get serviced, they told me they couldnt get the compressor to turn on, the swich didnt work, and they evern hooked it up to a computer and tried overriding my ecu none of that got my compressor to turn on.
they said it was prolly a bad ground, and gave me a good electric shop to contact, i told the electric guy my problem and he said prolly a bad ground. My uncle is a mechaninc for honda, but he agreed with them about it being a bad ground.

heres my question. If it is a bad ground does that mean it can be any one of those grounds you were talking about, or just the one of the two main ones. And do you think that by me replacing those 2 main grounds and adding 5 more like in the faq, that i will eliminate my problem?

 

[GTM]

...
my headlights dimmed significantly, nad when i turned on my lights, i noticed my stock stereo
...
the swich didnt work, and they evern hooked it up to a computer and tried overriding my ecu none of that got my compressor to turn on.
they said it was prolly a bad ground, and gave me a good electric shop to contact, i told the electric guy my problem and he said prolly a bad ground. My uncle is a mechaninc for honda, but he agreed with them about it being a bad ground.

heres my question. If it is a bad ground does that mean it can be any one of those grounds you were talking about, or just the one of the two main ones. And do you think that by me replacing those 2 main grounds and adding 5 more like in the faq, that i will eliminate my problem?

You may have as many grounds as you like, on 1G there was one from the intake manifold to the firewall and another from the front of the engine mount to it's bolts on the frame. If you forget to install those two then the alt has no body ground except through the throttle cable which can then burn and cause the throttle to stay wide open.

I don't know how familiar the electrical shop is with your A/C, there is a low pressure switch which prevents the compressor clutch from engaging when the system pressure is too low. If this switch fails or it's associated relay is bad then no matter if the system is full it will prevent the compressor clutch from engaging. With the engine off you can reach down and grab the center magnetic clutch which should rotate independent of the pulley to verify the compressor can turn. You can unplug the clutch activation wire and make a hot wire straight from the battery + to see if the clutch is able to be engaged when power is applied. Forgot to ask do your fans turn when the A/C is switched on?

Start the engine and now apply you clutch hot wire and the system should now blow cold air. If it doesn't then let us know and we can go from there.

After you car has been running for say 1/2 hour feel the ign switch and see if it's warm or hot. These switches can develop a lot of resistance and result in voltage drop. It does sound like you do have a bad ground somewhere so make sure the battery connections are clean, sand anything that looks like it has corroded. Check all the major harness plugs including those under the dash. Your schematic should show where the grounds are physically located.

You can probe these grounds which are contributing to the various function problems by using a voltmeter at the terminal and the other to body ground.

Cheers,
GTM

 

[luv2rallye]

well my chilton's wiring diagram shows a lot of grounds at specific locations in my engine bay but i cant find them, so am i missing something? i found the 2 your talking about, so if... those are the only 2, and i know i have a bad ground then replacing them with the 7 im getting should do the trick right?

I would start with the main battery cables. If you have a voltmeter you can measure any voltage drop from 1 end of the cable to the other with everything turned on (first with engine off then running). There should be none (or less than 0.1 volt). If you suspect one of the cables you can jumper across it with another known good one (like battery jumper cable) to see if problem goes away (or voltage drop decreases). Then remove the cables, clean their ends and places they attach to with sandpaper. Bend them along every inch to see if they feel cracked or old. If so replace them. Remember, even a 0.1 ohm resistance hairline crack in a cable that's running 30 amps will drop 3 volts which will produce problems. Battery cable internal cracks and poor connections are the #1 cause of electrical problems.

If satisfied with battery cables, remove alternator main cable and do the same. Be careful not to touch any metal as this one is hot. Disconnect battery before attempting this. Also make sure you have zero resistance from the alt. casing to battery negative, engine block, and body.

If that is ok then start looking for bad harness grounds using pictures from the manual to locate them (under Component Locations – Grounding). If you have any voltage on any harness grounds (to battery negative) with things turned on, you have a problem there (poor connection, broken wire - remember wires can be broken inside their insulation but look normal from the outside). The location of an internal break in a wire can be found by measuring continuity from one end to farther and farther places in the wire using a safety pin (attached to other meter lead) stuck thru the wire's insulation. Wiggle harnesses/wires/connections to see if problem changes and measure voltage at the ground points or resistance thru suspected wires. If a wire is shorted you will have to find it - installing another wire across it will not help. I have an article in Tech Guide electrical on finding shorts.

 

[eburg2490skillz]

so i have symptoms of a bad ground wire from loss of charge, flicker lights at idle after jumped and buzzing in the speakers. i found that my ground wire was spliced and flared pretty bad on the firewall. most of the wires are intact, but about a fith of them are torn and sticking out the cable. sorry i suck at electrical and im just making sure i should buy a new one and not try to crimp the wire and put electrical tape on it