Chevy with wiring issues

OK, champ

the ball's in your court

give me an example, and as Grandpa used to say 'This better be good'........................

Reply to
TranSurgeon
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Ya' think because you can install a car stereo, a remote start, a security system or goddamn neon lights you're in "the 12V industry?" Gimme a break...........................

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Doc

Reply to
"Doc"

hey my husband had the same problem on his 1990 fullsize blazer and he did the samething you did. we found that the ground wire in the lighting system wasnt grinded right so it drained the battery all the time.

Reply to
blazerchic

BlazerChic, You seem relatively new. I would suggest changing your reply-too email address w/ some spam preventatives, as well as finding the feature to quote the message you are responding too.

GMC Gremlin

Reply to
GMC Gremlin

its actually pretty easy bud. as voltage x current = power so, in a product like a car audio amplifier, power ratings are often at a fixed voltage of say 12.6 volts (resting battery voltage). If this amp physically makes 100 watts of power with an input of 10 amps at 12.6 volts, start dropping the voltage and watch what current does.

As the voltage dips, the current drawn INCREASES in an attempt to compensate and maintain the same level of power. There will come a point where either the amps protection circuit kicks in, or the power supply fails, and then current falls to zero.

Oh, and I believe that a few posts down yet another person has discovered how a grungy ground can cause excess current draw and, oops, drain a battery. I come back to my original point. Ohms law is a great thing, and if all conditions are perfect, it answers ALL questions. But in the automotive world - moisture, vibration, rust, heat, cold and a myriad of other factors play into things, making Ohms LAW a RULE at best in some cases. It doesn't always make sense.....and thats not an "upstart newbie talking", thats an MECP certfied 12V installer with 10 years industry experience talking....

so why ya callin me "champ" anyway? I sense a somewhat defensive stance? not sure why....

bmoney

Reply to
Hamilton Audio

thanks for the free advertising! ;) actually, what you see on that small website amounts to nothing more than hobby installations. interesting how defensive people get!! isn't it always what you /don't/ see that makes the man?? anyways....I work with 3 local, full time shops in town on a wholesale product/service basis year-round So I stay pretty well connected with the comings and goings of busy shops, and often participate first-hand in trouble-shooting and "interesting" cases....and believe me theres LOTS of em.

thanks for the note bud!

bmoney

Reply to
Hamilton Audio

great points gremlin. reminded me that my account was also setup as non-spam fighting. blazerchic - setup in your newsreader your email address with a few extra characters that make it false....then the bots won't getcha! ;)

bmoney

Reply to
Hamilton Car Audio + Security

Just here to help........

Doc

////////////////////////////////////////////

Reply to
"Doc"

figured you were. I guess the thing I was wondering most was....why so quick to jump on the offensive? i re-read this thread to see where I may have semantically gone wrong, and can't see it. I merely challenged the statement that ohms law cures all, based on MANY first hand experiences.. then we whip out the "you have no clue" flag on me, /assuming/ I'm a newbie. then it comes to a personal attack based on "you think you're in the industry?" when I try to tell you i'm not a newbie.

all of this without knowing a darned thing about me or my business. kinda made me wonder....thoughts?

Reply to
Hamilton Car Audio + Security

yes

I = E / R

Reply to
TranSurgeon

I can see that there is no reasoning with an unreasonable person. I guess you should give an ohms law lesson to blazerchic as well. seems that she solved the problem the same way that I proposed.

its clear you're not open to the idea that ohms law doesn't explain everything....

bmoney

Reply to
Hamilton Audio

what's 'unreasonable' about simple DC theory ?

YOU made the claim that you had 'seen current increase with a bad connection' (or similar), the upshot is that I asked you to post an example

none has been given

I'll give 'Ohm's Law Lessons' to anyone willing to learn how it applies, thank you.

Ohm's Law explains current flow in DC circuits

and the bottom line is this: for any given voltage, an increase in resistance will cause a decrease in current flow

as I said before, however, an increase in resistance may cause an increase in heating effects, according to P = I x I x R

given a 12-volt supply, and a resistance of 1 ohm, current is 12 amps (with me so far?)

now if you have a bad connection in that circuit with a resistance of 0.5 ohms, current drops to 8 amps (12 / 1.5 )

BUT you have 6 x 6 x 0.5 = 18 watts of HEAT produced in the bad connection

wait, it gets worse: at 1 ohm 'bad connection resistance' current is only 6 amps..........BUT heat in the bad connection is now 6 x 6 x 1 = 36 watts heating up your bad connection

I feel THIS is the source of your confusion........current is going DOWN, but the 'bad joint' is getting hotter.........to a point:

the point of 'max heating' in the bad joint is when the joint resistance is equal to the load resistance, at 2 ohms extra resistance, the current is down to 4 amps, but the heating at the bad connection is now 4 x 4 x 2 = 32 watts

now, any other questions ?

in

experiences..

Reply to
TranSurgeon

look down a few posts brother - you'll see an example given by me dated

12/3/2004 at 10:21 pm. I make the claim of seeing current increase with bad connections in car audio EVERY DAY. its that simple.

I guess you're adverse to hearing examples of things that cannot be explained by your friend ohms law. Its it too much to bear that yet another person on here has had the SAME experience? I can recount numerous examples of shitty grounds causing dead batteries.....

how come you never seem to address the point - but rather keep leaning on formulas that nobody gives a crap about? the point is this - when all else fails in a circuit, and something isn't working right, CHECK THE GROUNDS!!!!!!!!!!!!!!!!! that was the original statement I made, and I stand by it. as backed up verbally by at least one other poster here, and probably hundreds who don't want you to jump on them.

ever been to a doctor? health SCIENCES are pretty neat eh? but there are plenty o' things that they simply cannot explain. oh, but its a science. it MUST be explainable....you need to open ur mind a bit man. put down the physics book and open your mind....not everything falls within the realm of "explainable by theories/laws of physics". whether you like it or not.

still with me?

bmoney

Reply to
Hamilton Audio

no, it isn't

a 'bad connection', by definition, is one with increased resistance

increasing resistance decreases current

it is THAT simple

rant all you want about 'what you've seen'..............you may think you have seen 'curent increase with bad connections', but if you check properly, you will be surprised at what you are really measuring

oh............I see NO example given by you in your post...........if you REALLY want to continue this discussion, I suggest you re-post the 'example' and I'll be happy to tear it to shreds

back to you, bucko

until then,

wrote

Reply to
TranSurgeon

there we go with "by definition". the end result, "bucko", is that a shitty connection can lead to dead batteries. I see it with my own two eyes, therefore it must be true. testing "properly" or not, the end result is the same, is it not? is that not the original point of the first post???????

condition - battery keeps going dead on its own (there is a draw on the system somewhere) solution - cleaning up and repairing a bad ground removed the draw, and the battery no longer goes dead on its own reason - bad connection caused "something", which lead to a draw, which lead to a dead battery

do I have to spell it out to you any clearer? bad connections can lead to DEAD BATTERIES. others have confimred it here (or do you just read what you want to read?) 10 years of personal experience shows it to me over and over. any reasonable person can conclude then. if the battery was going dead, and a connection was repaired (with no other changes made), and immediately the dead-battery condition is repaired, the connection must be at fault.

once again you dodge the original point and lean on ohms law. explains nothing my friend. you still have not answered with your friend, ohms law, why repairing a sending unit ground fixed a small current draw on the battery at rest. that is, perhaps ur theories aren't always correct?

ps...look a little closer. my post is there for everyone to see.

bucko

bmoney

Reply to
Hamilton Audio

I really hate to get into the middle of these love fests, but a bad connection prevents the alternator from charging the battery, by not allowing the current through it, and the regular electrical load on the battery is what discharges it.

-Bret

Reply to
Bret Chase

hey, don't confuse him with facts, his mind is made up........................

Reply to
TranSurgeon

so where, exactly, was this 'bad connection' ?

c'mon, let's have it........WHERE did you find this mysterious 'bad connection that caused a current draw' ???

Reply to
TranSurgeon

which wire exactly ?

where is it located ?

specifics, please

Reply to
TranSurgeon

Some things defy rational debate. Religion, politics and now Ohm's Law. :-)

Someone makes an observation about poor grounds and/or connections. Then a conclusion that 12 volt DC circuits don't necessarily follow Ohm's Law.

When that conclusion isn't acceptable to others, the validity of the observation itself is questioned. Then other's add their experiences of similar circumstances.

One group is saying "I've seen it, therefore its true." The other is saying "I've never seen it, therefore its false."

Well, "I've seen it before, the observation is true, but the conclusion is false." So there!

It might have been more accurate to conclude that today's automotive wiring systems appear to defy Ohm's Law. Other voltages in both DC and AC are often used and the wiring diagrams available to the backyard mechanic are poor at best.

To illustrate the possibilities, here's the horror story of my wife's Buick.

After a lengthy highway trip with a full car, I parked in the garage, turned off the ignition, removed the cell phone adapter from the cigarette lighter and tried to replace the lighter. It didn't go in properly until I removed a piece of the adapter from the socket. The interior lights have a delayed off feature (as do the headlights) so it was normal for lights to remain on when I left the vehicle.

On leaving 20 minutes later for a short trip, the interior lights were still on which I assumed was due to someone leaving on a light switch during the recent trip. However, there wasn't any power to the dash. No lights, no heater, no radio and no cigarette lighter power. Everything else was fine so off I go. Within an hour and a half after the next stop the battery was dead. A boost got me home and the fun began.

With Ohm's Law more or less the guiding principal, I started troubleshooting. The problem initially started with the end of the cell adapter shorting the cigarette lighter. But none of the fuses labeled, dash, interior, heater, lights, radio etc. were blown. And the only way of turning off the interior lights was to remove the fuse for them. Anyway how could a blown fuse turn an interior light on? I suspected the short heated a wire, melted the insulation, etc. etc.

I eventually had the dash stripped to the firewall tracing the orange power wire that feeds the cigarette lighter, the radio, the heater/AC control module and found nothing. No shorts, no breaks, and no power. It was clearly time to give up and send this mess to the wreckers. (We're talking 100 + manhours now.) So for the hell of it, I took a wire from the battery and touched the center of the lighter socket. The interior lights went out. ????

There turned out to be only one problem. A fuse had blown but was labeled as something else and consequently missed at the start. Being quite annoyed with mysellf, I quickly slapped it back together without invetigating the exact reason for the apparent illogical behavior - namely blown fuse = discharged battery.

My conclusion does not dispute Ohm's Law, nor does it question the validity of my observations. So what might have happened?

The interior lights are on with the doors open and for a delayed period after they are closed. The power to these lights is fed through a relay. The cicuits controlling that relay, including a time delay may be a little convoluted. Consider that the coil is de energized when the potential across it is zero. That can be grnd on both sides OR 12 volts on both sides.

Now consider power fed to both sides of a relay coil and a resistor to ground at each side. Grounding either side energizes the relay. Similarly removing the 12 volts from either side energizes the relay. I think this was my situation with a missing voltage on one side due to the blown fuse. (Note to purists: Yes the polarity matters. But diodes, duplicate coils/relays could provide the stated effect)

So can a bad ground, poor connection or blown fuse discharge a battery? Indirectly yes! Does that contravene Ohm's Law? No. Now I really doubt that this type of circuit was unique to the 1994 LeSabre interior? How about delayed off headlights? Seatbelt warnings? etc. etc.

We're all correct. Let's play nice.

Bob

Reply to
noone

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