[Guest]

Car sitting for 5 days.............started up vehicle and I have none of the following:
seat settings
no gages working
trunk won't open
top of course will not work
side windows will not reset the last inch
DIC reading just about everything wrong with vehicle that can go wrong.
Vehicle running very erratic.
Called On Star to run a diagnostic...............lost connection between major components.
My buddy Hans suggestion in GERMANY was to,"Disconnect battery on one post for 20 seconds".
The people on the forum know more about this car than GM does and they come to your aid.
Thanks Hans

 

[harrysxlr]

Car sitting for 5 days.............started up vehicle and I have none of the following:
seat settings
no gages working
trunk won't open
top of course will not work
side windows will not reset the last inch
DIC reading just about everything wrong with vehicle that can go wrong.
Vehicle running very erratic.
Called On Star to run a diagnostic...............lost connection between major components.
My buddy Hans suggestion in GERMANY was to,"Disconnect battery on one post for 20 seconds".
The people on the forum know more about this car than GM does and they come to your aid.
Thanks Hans

It was a pleasure to help and I`m glad it worked in your case:thumbs :thumbs :thumbs

I know how bad we feel when somethings wrong on our cars and it`s even more worse when it happens on a weekend.

Hans

 

[XLR I FL]

Bob:

You just sucessfully completed the first "XLR USER REBOOT" congratulations!!!

 

[Guest]

I zip tied a small ratchet with socket near the battery in case I have to take off the POS strap again on the battery............Ya just never know what's going to happen next.
I'll probably have tools zip tied all over the car by next year
Bob (user friendly)

Bob:

You just sucessfully completed the first "XLR USER REBOOT" congratulations!!!

 

[Caly]

I zip tied a small ratchet with socket near the battery in case I have to take off the POS strap again on the battery............Ya just never know what's going to happen next.
I'll probably have tools zip tied all over the car by next year
Bob (user friendly)

It's always a good idea to remove the NEG battery cable first. It connects to the frame (and body panels in metal cars). The problem is that if the NEG is still connected when you disconnect the POS terminal it is possible to short the wrench between the battery and any metal (grounded) in the car. The result is very dramatic... lots of sparks, welding of metal and possibly fire.

Let's be careful out there.

 

[Guest]

Not to make light of your suggestion.

The correct way, as a member of the International Electrical Workers Union, is to attach the ground first to any system and it's the last wire to be disconnected. Reason: If your ground is attached you have a better chance of having any accident go to ground instead of going through your body.

I work with 12,000 volts HOT in my everyday job while protected by re-closures that will kick out a circuit within 1 second if it goes to ground which will give the person a good chance of surviving if they get into the 12KV.
As a side note............College students have proved that AC current is more expensive than DC current and in the future you will see more homes with DC current that will store current not used in a capacitor built into your home. Alternating current looses a lot of energy while traveling along wires. Many high lines do what's known as a transpostion which is the crossing of wires from positions to complete opposite postions in order to pull back energy from wooded areas. This transpostion takes place over three spans of poles or towers.

Thomas Edison was laughed at for suggesting DC would be cheaper, but AC was chosen as our power grid. We now find out he was correct and DC power, while being more dangerous, is a much cheaper fuel for everyday living. That new Hybrid will plug right into any DC outlet in the future.
Thank You
Bob
While information is great on any level, misinformation can harm as well. Also a ratchet with an extension doesn't get into anything else if properly used.

It's always a good idea to remove the NEG battery cable first. It connects to the frame (and body panels in metal cars). The problem is that if the NEG is still connected when you disconnect the POS terminal it is possible to short the wrench between the battery and any metal (grounded) in the car. The result is very dramatic... lots of sparks, welding of metal and possibly fire.

Let's be careful out there.

 

[Caly]

Standby,

I certainly agree that in earth grounded systems where one's body could become an intrigal part of a circuit... leave the ground attached first and last.

The key is the possibility of becoming a member of a circuit, which with a 12 volt DC system, the worry is amperage not voltage. Let's say you are holding a wrench to the positive terminal with the negative still connected. You get your wedding band or watch between the wrench and a metal part on the car... you will likely lose a finger at least as the ring will become red-hot instantly. If you do the same thing with the negative terminal absolutly nothing will happen... and once the negative is disconnected you can not complete a circuit from the postive to the frame.

The right answer in one circumstance may be the wrong one in another. This is a good example of that.

 

[Guest]

Caly,
I do apologize for gesturing and do agree with you if one is that clumsy to do the things you say, they need to be very careful, but being in this field for over 50 years and, "knock on wood", have never had one incident that was worth mentioning or repeating and work very hard at safety to make sure it doesn't happen to me or anyone I'm working with.
Being a very strong advocate on safety, I guess your advise is well taken.
Bob

 

[rufcar]

re boot

Hi guys I know this is a late post but then again im a new xlr owner 3 weeks! I have a bunch or cars and use the green knob battery disconects. They are available from Eastwood for about 10 bucks and once on ( 5 min job tops) just unscrew knob on neg post, You can also take the knob and no one can start the car! Or use the one with a trickle type diode then when charging over winter it lets enough power thru to keep all computers info intact! Im anxious to meet you all in BG in aug! Ill be home from the Rolls nat'l like 3 days then off with you guys YEA!!! The xlrs about as much fun as Iv ever had (other then racing!) Keep driving! Jim

 

[Sparky]

Not to make light of your suggestion.

The correct way, as a member of the International Electrical Workers Union, is to attach the ground first to any system and it's the last wire to be disconnected. Reason: If your ground is attached you have a better chance of having any accident go to ground instead of going through your body.

I work with 12,000 volts HOT in my everyday job while protected by re-closures that will kick out a circuit within 1 second if it goes to ground which will give the person a good chance of surviving if they get into the 12KV.
As a side note............College students have proved that AC current is more expensive than DC current and in the future you will see more homes with DC current that will store current not used in a capacitor built into your home. Alternating current looses a lot of energy while traveling along wires. Many high lines do what's known as a transpostion which is the crossing of wires from positions to complete opposite postions in order to pull back energy from wooded areas. This transpostion takes place over three spans of poles or towers.

Thomas Edison was laughed at for suggesting DC would be cheaper, but AC was chosen as our power grid. We now find out he was correct and DC power, while being more dangerous, is a much cheaper fuel for everyday living. That new Hybrid will plug right into any DC outlet in the future.
Thank You
Bob
While information is great on any level, misinformation can harm as well. Also a ratchet with an extension doesn't get into anything else if properly used.

I have to agree with Caly.
I too am a member of the IBEW and was taught that in a DC battery circuit, current flows from negative to positive, not positive to negative as most lay people think. Therefore inadvertently contacting the negative terminal to ground will not spark since they both have the same potential. In this case the negative terminal should be disconnected first. In an AC circuit the hot should be disconnected first, then neutral and ground last as you pointed out.

Also in regards to the competition between Edison and Tesla as to which was cheaper and more practical to implement AC or DC, Tesla proved AC was superior for power distribution, because AC is far easier and cheaper to transform to different voltages. This was one of the main reasons AC was chosen for the power grid.

 

[harry yarnell]

Good point Sparky. Can you say 'transformers'?

In this totally unrelated discussion on AC vs. DC power transmission, how do you step down DC?

 

[Guest]

Well, I almost had everything right..........I yield to Sparky with the DC knowledge.
I believe you use a converter to step down and and inverter to step up.
Bob

Good point Sparky. Can you say 'transformers'?

In this totally unrelated discussion on AC vs. DC power transmission, how do you step down DC?

 

[harry yarnell]

An inverter would be prohibitively expensive for the national power grid. Transformers make the transition in voltage very easy and cheap. And besides, we wouldn't have induction motors with DC.

 

[Guest]

Harry,
Sorry, I was talking about DC on cars, vans, trucks motorhomes. etc. not the national grid.

An inverter would be prohibitively expensive for the national power grid. Transformers make the transition in voltage very easy and cheap. And besides, we wouldn't have induction motors with DC.

 

[Guest]

sparky
This was also over a hundred years ago and these students are equipped with much more information today than back then and I would lean toward their studies and tests for the future. Line loss of electricity is one of the fall backs of AC. DC doesn't have any line loss, or I should say minimal.
Just an old clum sum.

Also in regards to the competition between Edison and Tesla as to which was cheaper and more practical to implement AC or DC, Tesla proved AC was superior for power distribution, because AC is far easier and cheaper to transform to different voltages. This was one of the main reasons AC was chosen for the power grid.

 

[jjxlr]

thank you

Thank you soooo much my xlr did the same thing. I think my battery is going dead. but like you said just remove the negative terminal wait 20 seconds, and then replace the terminal. and bam the car works perfect! thanks again:iagree

 

[xlr pilot]

AC versus DC

An interesting series of comments about electricity.
Long distance transmission of DC is more efficient than AC. I work for the Bonneville Power Administration here in Portland OR. We have a direct current line between The Dalles OR. and Los Angeles CA. It runs non-stop to L.A.(no enroute substations). The AC from our main grid is converted to DC by a series of Thyristors and then shipped to LA where it is re-converted to AC at Sylmar CA. When the line was built in the late '60s a device called a mercury arc valve did the voltage conversion work. That was later replaced by the thyristor group. Long distance AC transmission is now more often used because of the improvement of capacitor groups to maintain correct frequency (cycles). Inverters convert DC to AC in low voltage circuits (12 V)
Transposition structors that rotate phases of AC lines are there to improve power factor, a measure of efficiency. None of which has anything to do with XLR but is interesting nontheless. I agree that the negative lead comes off first in 12 V use. Eric:jester

 

[Guest]

Very good post, never to old to learn, BUT, being the thread designer of this post and a lineman for San Diego Gas & Electric my first instinct was to to leave the ground on to last. When working with secondaries or 12KV the ground is the first thing on and the last thing off, now on a car you may be right, but I did disconnect the pos. first just like in line work. It seems to have worked OK that way, so maybe it doesn't make any difference on a car.
On another note, is the reason you are sending power to us in DC because it is cheaper and less loss on the line or some other reason. Sure would like to know.
Long time Transmission Lineman at 75 and still working in the field, but not climbing.
Bobo

An interesting series of comments about electricity.
Long distance transmission of DC is more efficient than AC. I work for the Bonneville Power Administration here in Portland OR. We have a direct current line between The Dalles OR. and Los Angeles CA. It runs non-stop to L.A.(no enroute substations). The AC from our main grid is converted to DC by a series of Thyristors and then shipped to LA where it is re-converted to AC at Sylmar CA. When the line was built in the late '60s a device called a mercury arc valve did the voltage conversion work. That was later replaced by the thyristor group. Long distance AC transmission is now more often used because of the improvement of capacitor groups to maintain correct frequency (cycles). Inverters convert DC to AC in low voltage circuits (12 V)
Transposition structors that rotate phases of AC lines are there to improve power factor, a measure of efficiency. None of which has anything to do with XLR but is interesting nontheless. I agree that the negative lead comes off first in 12 V use. Eric:jester

 

[C-A-R-S]

I agree that the negative lead comes off first in 12 V use.

As a shop owner, always negative first in disconneting battery in 12V Direct Current auto applications. ( http://en.wikipedia.org/wiki/Direct_current )
In AC, as your home, of the two wires that feed a light in your home, neither is negative, they are both alternately negative and positve, hence Alternating Current.
( http://en.wikipedia.org/wiki/Alternating_current )
These two wires are usually black and white.
The third wire usually bare or green is the ground.
In your car, the red post or + cable represents the Hot wire or positive post, and the black or - cable the ground or negative post.
In a modern car, the metal frame and body of the car acts as the ground for the vehicle, so only one hot wire has to be run to most components.
Until the 1950's or so most American cars used a positive ground, meanig only one wire had to be run to most light etc. with the positve connection being the body of the car.
I believe the Army teaches electricity flows positive to negative and the Navy teaches negative to positive. It doesn't matter which way it flows as long as you understand it takes a complete circuit (positive connecting to negative or vice versa) to make electricity flow.

So in a modern car with a negative ground, if you are removing the negative wire and your wrench tiuches any metal part of the vehicle, nothig will happen.
However, if you are removing the positive cable and you touch any metal part of the vehicle, you would create a short to ground and possibly cause your wrench to weld itself to either or both ends or cause the battery to heat and explode.

 

[Guest]

Ya know now that I visualize myself disconnecting a battery you guys are all correct, even though I do it the opposite way with DC. I disconnect the neg first for the same reason stated here. You can drop the neg and not worry about it. I learned that lesson to many years ago by shorting out the battery by grounding out the hot post with a wrench, and I did it this way when I removed my wire to reboot the computer. Wish I could change that first post so people wouldn't do it the wrong way. Can you change it Marc?
Bobo

I agree that the negative lead comes off first in 12 V use.

As a shop owner, always negative first in disconneting battery in 12V Direct Current auto applications. ( http://en.wikipedia.org/wiki/Direct_current )
In AC, as your home, of the two wires that feed a light in your home, neither is negative, they are both alternately negative and positve, hence Alternating Current.
( http://en.wikipedia.org/wiki/Alternating_current )
These two wires are usually black and white.
The third wire usually bare or green is the ground.
In your car, the red post or + cable represents the Hot wire or positive post, and the black or - cable the ground or negative post.
In a modern car, the metal frame and body of the car acts as the ground for the vehicle, so only one hot wire has to be run to most components.
Until the 1950's or so most American cars used a positive ground, meanig only one wire had to be run to most light etc. with the positve connection being the body of the car.
I believe the Army teaches electricity flows positive to negative and the Navy teaches negative to positive. It doesn't matter which way it flows as long as you understand it takes a complete circuit (positive connecting to negative or vice versa) to make electricity flow.

So in a modern car with a negative ground, if you are removing the negative wire and your wrench tiuches any metal part of the vehicle, nothig will happen.
However, if you are removing the positive cable and you touch any metal part of the vehicle, you would create a short to ground and possibly cause your wrench to weld itself to either or both ends or cause the battery to heat and explode.