Ground Wires

[clivvy]

chaps,

I wanna check my ground wires in the engine bay. I understand cleaning them, but just to clarify, from engine block to chassis, where should each ground wire mount? should the surface be bare metal? Can I improve the ground wires in anyway?

 

[rayf3262]

Star/serrated washers are a good choice between painted steel and copper connections.

If exposed to the elements, keep the connection moisture free by using a grease or similar to avoid galvanic reaction between the dissimilar metals.

 

[rustic]

Star/serrated washers are a good choice between painted steel and copper connections.

If exposed to the elements, keep the connection moisture free by using a grease or similar to avoid galvanic reaction between the dissimilar metals.

Waxoyl does it for me.
I always keep a jar of it in the garage ready for action.:thumb2

 

[briggie]

Waxoyl does it for me.
I always keep a jar of it in the bedroom ready for action.:thumb2

 

[rustic]

You've been peeking in my drawers again.....:augie


:lol:lol

 

[clivvy]

Star/serrated washers are a good choice between painted steel and copper connections.

If exposed to the elements, keep the connection moisture free by using a grease or similar to avoid galvanic reaction between the dissimilar metals.

ahhh, thanks Ray, I dont have any of them on any of my ground wires, so I will pick some up this weekend. Is regular grease ok?

also, I read about fitting extra ground kits, is this possible?

 

[rayf3262]

ahhh, thanks Ray, I dont have any of them on any of my ground wires, so I will pick some up this weekend. Is regular grease ok?

also, I read about fitting extra ground kits, is this possible?

Rustic's suggestion to use Waxoyl is a good one, if you've got an eggcup full somewhere!
Otherwise whatever you have to hand will be better than nothing.
You can fit additional grounding cables, but before you do that it makes sense to check the existing ground points first.

A simple check: connect one of your test meter terminals to the battery -ve with a longish cable then you can roam around the vehicle with the meter and other test probe and check the ground points. You are checking for the ideal of zero volts between the battery -ve & selected ground point, a few 10's milli-volts is acceptable, ~250mV and above could suggest room for improvement.
You should carry out these checks with the electrical system loaded and un-loaded. Switch on/off headlights/heated screen/brake lights etc. and look for any abnormally high voltage reading on the ground point being checked when something is switched on/off.

 

[clivvy]

Rustic's suggestion to use Waxoyl is a good one, if you've got an eggcup full somewhere!
Otherwise whatever you have to hand will be better than nothing.
You can fit additional grounding cables, but before you do that it makes sense to check the existing ground points first.

A simple check: connect one of your test meter terminals to the battery -ve with a longish cable then you can roam around the vehicle with the meter and other test probe and check the ground points. You are checking for the ideal of zero volts between the battery -ve & selected ground point, a few 10's milli-volts is acceptable, ~250mV and above could suggest room for improvement.
You should carry out these checks with the electrical system loaded and un-loaded. Switch on/off headlights/heated screen/brake lights etc. and look for any abnormally high voltage reading on the ground point being checked when something is switched on/off.

nice one Ray, I will do just what you suggest tomorrow unless its blowing a gail hail!! youre advice and knowledge is being really helpful to me at the moment, so thankyou very much.

 

[Fez_uk]

Vaseline works well

 

[rustic]

Vaseline works well :naughty

You always change topic, try to keep to the content of the thread.:lol:lol

On every car I aquire I always brush waxoyl on all the body earths.
I also cover my nuts and bolts as well..

 

[clivvy]

ok, I have results. NO idea what I am doing, so bear with me.

I didnt know what setting to use on the dial, so I set to "200m" Volts (left of the dial)

I attached the black wire to the battery negative, and used the red to prod the ground wires.

loaded/Unloaded, I found:

2 small ground wires 16.5 (these are the two on the engine block)/00.3

Engine to chassis (next one in line) 23.2 / 00.3
small wire from loom near washer 23.5 / 00.5
battery negative to engine 08.4 / 00.1

does that mean anything to anyone??

also, I noticed that an old positive battery cable I have left in the car-detached or so I thought, is reading quite a high voltage, 43.2. Thing is, I thought this was detached as I fitted a new one, does this mean anything??

 

[kitchenman]

200m volts I think is milli volts thats 1/1000 of a volt, so the max reading will be 200mili volts, thats 1/5 of a volt AIR 1000/200 = 5

Check this out set your voltmeter to 20, put the probes on the battery terminals, should read 13.8 ideal but most likely around 12.5, if you get the probes round wrong way you will get -12.5 for instance

Set to 2 & will read around 1.5 on a AA battery

Hope this helps a bit

 

[rayf3262]

loaded/Unloaded, I found:

2 small ground wires 16.5 (these are the two on the engine block)/00.3

Engine to chassis (next one in line) 23.2 / 00.3
small wire from loom near washer 23.5 / 00.5
battery negative to engine 08.4 / 00.1

also, I noticed that an old positive battery cable I have left in the car-detached or so I thought, is reading quite a high voltage, 43.2. Thing is, I thought this was detached as I fitted a new one, does this mean anything??

The results of what you have tested look ok to me.
Under load, circa 20mV between batt. -ve and the ground points checked is good, certainly no cause for any concern.

Not sure I understand what the "old positive battery cable" is??

 

[rustic]

ok, I have results. NO idea what I am doing, so bear with me.
I didnt know what setting to use on the dial, so I set to "200m" Volts (left of the dial)
I attached the black wire to the battery negative, and used the red to prod the ground wires.
loaded/Unloaded, I found:
2 small ground wires 16.5 (these are the two on the engine block)/00.3
Engine to chassis (next one in line) 23.2 / 00.3
small wire from loom near washer 23.5 / 00.5
battery negative to engine 08.4 / 00.1

does that mean anything to anyone??

also, I noticed that an old positive battery cable I have left in the car-detached or so I thought, is reading quite a high voltage, 43.2. Thing is, I thought this was detached as I fitted a new one, does this mean anything??

Wow, what you are trying to do is actually quite advanced.:thumb2:thumb2
What you are doing is measuring the voltage drop in the cable in mV when under load and not under load. :augie
Thus you can determine the resistance of the cable or connection very accurately, more accurate than using the ohms range on the meter.:clap

Now, ok for me to do, as my first career was an electronic engineer, but was this what you really wanted to do?:doh


The detached cable is reading 43.2 mV not volts so this is 0.043 Volts not very much.

I'm nearly impressed, I think....

Best regards, Rustic

 

[clivvy]

The results of what you have tested look ok to me.
Under load, circa 20mV between batt. -ve and the ground points checked is good, certainly no cause for any concern.

Not sure I understand what the "old positive battery cable" is??

dammit, I was hoping it was wrong, so I could fix it!!

let me explain about the positive battery cable. basically, what I mean is, you know the cable that goes from the positive terminal on the battery, down to the starter? That. I had to change it a while back,. but couldnt remove the old one from the loom, so I just left it. Put the meter on it today, and its showing voltage!! should be just dead...

 

[clivvy]

Wow, what you are trying to do is actually quite advanced.:thumb2:thumb2
What you are doing is measuring the voltage drop in the cable in mV when under load and not under load. :augie
Thus you can determine the resistance of the cable or connection very accurately, more accurate than using the ohms range on the meter.:clap

Now, ok for me to do, as my first career was an electronic engineer, but was this what you really wanted to do?:doh


The detached cable is reading 43.2 mV not volts so this is 0.043 Volts not very much.

I'm nearly impressed, I think....

Best regards, Rustic

cheers Rustic!

I am not very good with electronics, but I want to learn so I am persistent and patient! anyway, this is what I was wanting to do yes, measure the voltage drop etc. I was actually hoping for a problem, but it seems all is well with the readings I achieved. which just adds to my current issue of not being able to find the source of my pedal electrical fault. anyhoo, plan now, is to fit new washers to each ground point after a good clean and maybe re position a few of the ground wires. If I am lucky, this will fix my random code 47 from the pedal!

 

[clivvy]

200m volts I think is milli volts thats 1/1000 of a volt, so the max reading will be 200mili volts, thats 1/5 of a volt AIR 1000/200 = 5

Check this out set your voltmeter to 20, put the probes on the battery terminals, should read 13.8 ideal but most likely around 12.5, if you get the probes round wrong way you will get -12.5 for instance

Set to 2 & will read around 1.5 on a AA battery

Hope this helps a bit

that certainly does help mate, thank you! I will double check the battery, but I think that's ok...

 

[rayf3262]

dammit, I was hoping it was wrong, so I could fix it!!

let me explain about the positive battery cable. basically, what I mean is, you know the cable that goes from the positive terminal on the battery, down to the starter? That. I had to change it a while back,. but couldnt remove the old one from the loom, so I just left it. Put the meter on it today, and its showing voltage!! should be just dead...

It sounds as though that old cable is still connected at least at one end!
It won't do any harm providing:
The other end is securely insulated and tied down safely out of harms way, if it shorts to ground anytime it won't take any prisoners!

 

[clivvy]

It sounds as though that old cable is still connected at least at one end!
It won't do any harm providing:
The other end is securely insulated and tied down safely out of harms way, if it shorts to ground anytime it won't take any prisoners!

hmmm....very odd Ray, because I am 99% sure its disconnect the bottom end, as that was the end that attached to the starter!! I wonder if its touching the starter, and if so, would that cause any anomalies??

next job is to insulate both ends or attempt to remove....

 

[kitchenman]

A shorted battery is a bomb:doh, massive discharge of hydrogen + sparks = boom

When I was doing national service a mechanic dropped a spanner across the terminals of a battery, boom, we wondered why he ran away about 1 second before the boom