replacing factory 10 gauge wire did wonders

food for thought

all i can say is wow!



I sure as hell can't seem to understand why my car don't have all these voltage drops/ amps dropping due to having the stock wire on the alt.


well lets see here!

I have dual fans, hi-output Fuel pump, silver star headlights, a/c with auto climate control, power windows/locks, Fast XFI, am/fm cd player with 3 amps in the trunk! 2 100 watt amps and 1 500 watt amp.


For some dang odd reason my battery stays charged. So do i happen to have the accident that gm built. no


BTW your taking the voltage reading from the scan master did it ever occur to you that the ecm curcuit could be having a issue thus causing your voltage drop.

Try taking another voltage reading at the battery then another at the cigerette lighter and note the diffrence. then compare those to what the scan master shows.


I also find it amazing as people think you need a larger wire from the alt to the battery.

But not up sizing the fuse links and wires that feed all the switched acc and non switched acc that get powered from inside the car?

The alt wire has nothing to do with those wires. Those fuse links/wires connect at the starter.

So your voltage issues are from the starter connections to inside the cab of the car.

Someone mentioned about running the larger alt wire to the starter VS the battery. Did it ever occur to you that the battery cable to the starter is way bigger than the larger 6 gauge wire. So there is nothing to gain by doing that.



Turbo loyd

I like how you mentioned the fuse ratings and added them up for a grand total of 172 amps. Did it ever occur to you that the Alternator on a TR is 120 amp unit or hell the upgraded one is 140 amp. So adding the larger wire does nothing to the battery and its having more power drawn off of it than what the alt can provide. so that don't make any sense to me?


Also the fuse ratings have a little give in them as well. do you really think if the radio has a 10 amp fuse in it that it really is consuming 10 amps .

Fuse sizing has to deal with faults. If one were to pull 10 amps on a 10 amp fuse, the fuse would eventully fail due to thermal resistance and then the fuse melts and thuse no connection.




Something that i learned along time ago is basic electronics is. "The root of all evil is nothing more than a bad connection"
 
more to the truth about electricity/wire size

Let’s take a look at a couple facts. First let’s look at the factory charge wire. It is not a 8 gauge. It is not a 10 gauge. It is a 7 gauge. It is approx ..1425” in diameter. It is made up of 19 conductors of 21 gauge wire twisted together.



The wire supplied in the GN harness the wire is exactly 65 inches long. Since 7 gauge is about 498 micro ohms per foot that equates to about 2.697 milliohms for the entire wire.



Now consider the video made by Richard.

He said he paralleled the factory wire with a 1/0 cable. Since most jumper cables are in the 8 foot ranges lets do a few calculations on what that might have been like. Since a single foot of 1/0 is about 98.3 micro ohms an 8 foot piece would equal about 786.4 micro ohms.



A comment was made that the charging increased by about 25 amps when the large wire was connected so that showed an improvement. But Richard clearly stated that the increase of current in the large wire is accompanied by an identical DECREASE in the factory wire. This means that before the large wire was attached the current in the factory wire would have been much higher. How can you guys think that the increase of current of 25 amps as was shown could have happened if the voltage drop was not more than a few tenths of a volt?



How much higher was it? I believe he took it for granted that everyone would either listen or logically understand that is what was actually happening. The ratio of resistance between the two conductors is about 3.43:1. Using the standard formula found in virtually all elementary electronics textbooks



1/Rt = 1/R1 + 1/R2



the parallel resistance of the two wires would be approximately 608.8 micro ohms. If the current in the large wire was 25 amps the above formula says the current in the factory wire would have been about 32 amps before the large wire was connected. At that rate the drop would have been about .08 volts until the large cable was paralleled. At the same time the drop would have been about ..02v as the large wire hogged most of the current due to its lower resistance. Likewise as the large wire conducted the 25 amps the current in the factory wire would have dropped to about 7 amps.



The load would have been relatively constant and the change of voltage drop would have been about the .1v as was shown.



If this doesn’t make sense and the logic fails you imagine the following. You are carrying a piece of furniture that weighs a hundred pounds and you ask for help carrying it. A much stronger person than you grabs to help you and he actually exerts 70 lbs of lifting force on the furniture. You are going to now be carrying only 30 pounds of the weight. It would be pretty weird to think that the furniture was going to gain 70 lbs of weight and you were still going to be carrying the original hundred pounds. That’s exactly what that interpretation of the video seems to be.
 
daves87gn said:
2. and here is the biggie, resistance of the stock wire once heat is applied? the stock wire is wrapped all around items that generate a lot of heat?

heat = resistance and if your stock cable is having a issue heat will multiply the problem IMO

I highly doubt there will be much difference in the the new wires, the old wires resistance being the bigger problem.
QUOTE]



It has been expressed that things might change a lot if the wire got hot. It
is true that temperature changes the resistance of wire. Since most element
charts use STP (standard laboratory temperature of 32 degrees and pressure
of 1 atm) we should make allowance for temp in our calculations. It is true
that the voltage drop would increase but just how much? And how hot might
the wire get under the hood of a GN? With air flowing even on a hot day the
air temp sensor might record 150 degrees but for the sake of being
conservative we will go with 200 degrees. Also to make the calculation
easier we will assume that the entire length of the wire is the same
temperature.

The resistivity of copper is approx 1.724 x 10^-8 ohm*m and the temperature
coefficient of copper is 3.9 X 10^-3/C

Rounding the 65 inches to 5 feet to make calculations easier the resistance
of 5' of 7awg solid wire is 0.002491 ohms @ 20 C (68 F). The resistance of
the same wire would be 0.003203 ohms @ 93.33 C (200 F). The difference in
resistance with the 73.33 C temperature increase is 0.000712 ohms. This
would create an additional voltage drop of about 0.03 volts.

Additional heating would be caused by the actual flow of current in the
wire. This is easily calculated by the formula of E^2/R. In this case the
answer would be 2.761 watts at 68 F and close to a whopping 4 watts at 200
F. About the heat of a flashlight bulb distributed throughout the length of
the wire. Pretty insignificant overall.

Fact remains that the issues here are very minor. The engineers at GM knew
exactly what they were doing when they designed the charging system to begin
with and nothing about electricity has changed much since 1987.
Click to expand...
 
my head hurts...

after reading all this. ohm's law isn't really a law, is it? i always thought it was more like a rule of thumb... :p
 
On my work truck - 3-batteries, 1-aims 5000, 1-air compressor

Because of this thread i think i figured out why my 240 amp alt couldn't keep up with my Aims 5000.
I have all the batteries (three) tied together via a Zero gauge wire and the aims 5000 tied to the lead from the batteries is also a Zero gauge. I just never up dated the Wire from the alt to the main vehicles battery which is where i started with the Zero gauge wire to the other 2 batteries.

According to this thread if i connect a Zero gauge wire from the alt to my main battery i will/should be able to use the full 240 amps that my alt is suppose to be putting out?????
 
so what is the proper way to check the fusible links from the starter to the inside of the car ?
 
TURBOPOWERED68 said:
On my work truck - 3-batteries, 1-aims 5000, 1-air compressor

Because of this thread i think i figured out why my 240 amp alt couldn't keep up with my Aims 5000.
I have all the batteries (three) tied together via a Zero gauge wire and the aims 5000 tied to the lead from the batteries is also a Zero gauge. I just never up dated the Wire from the alt to the main vehicles battery which is where i started with the Zero gauge wire to the other 2 batteries.

According to this thread if i connect a Zero gauge wire from the alt to my main battery i will/should be able to use the full 240 amps that my alt is suppose to be putting out?????
Click to expand...

Yes exactly, you need the proper size wire to transfer the power.
 
Put a volt meter to a good ground on each fuse in the panel and run/turn on the circuit it protects.

If it's over 12 volts car running, drive it. :)
 
Any Stock replacement wire from the alternator to the battery would of worked because after 27+ yrs, there is plenty of corrosion causing more resistence (ohms law) which makes your alternator work harder and less efficient. It would also greatly improve your electrical system by having larger grounds, not necessarily larger positive cables (than stock). As stated before, larger diameter wires can cause voltage drops too do to the increased resistance created. A larger ground helps no matter what. Lots of body grounds would be more beneficial as well.
 
I beg to differ on larger pos wire causing voltage drops from increased resistance. Larger wire ...copper stranded for example... will conduct and handle more current easily with less resistance.
 
turbo nasty said:
I beg to differ on larger pos wire causing voltage drops from increased resistance. Larger wire ...copper stranded for example... will conduct and handle more current easily with less resistance.
Click to expand...
Let me rephrase since it is winter and everyone is so friggin literal and up tight ... sized accordingly.
 
Wahoo said:
Where are they located?
Click to expand...
there are quite a few fusible links throughout the harness a few are in the dash wiring where they are very hard to access these rarely fail or GM would not have put them in such a location the main ones are a few inches from the starter Positive terminal on the three red wires that lead to the wiring harness at the rear of the engine don't worry about them they are either good or bad almost all the wiring in the car is fed from these links and if EITHER of them has failed you will have no doubts LOTS of things will not be working think of them as air bags for electricity air bags only fail if you have an accident that you are not likely to drive away from or if someone that doesn't know what he is doing goes poking under the dash into the wiring same with the fusible links i have worked on many hundreds of GN's over the last couple decades and a problem with these is extremely rare unless some electrical genius like some of the gurus on this thread have been piddling around the car if these links worry you I would suggest that you worry more about godzilla eating your car since they both have about the same chance of happening and this silly thread is a great example of the downside of the internet as a source of information lots of misinformed people posting thoughts as if they have more than a clue what they are typing about EXAMPLE # ONE we have some that doubt Ohms law is it written in the constitution? no but it is a physical law that some very smart men have discovered that all relevant forces in the known universe adhere to truly knowledgeable people know that when something doesn't seem to obey it that their observation is somehow flawed case in point someone mentioned that they measured a wire and the drop did not agree with a voltage drop chart odds are that in their flawed analysis they failed to use a Kelvin style attachment to the wire under test and left the connectors in the equation slogn stated it well when he said "the devil is always in the connections" think about it we have technically challenged folks measuring voltage drops (some in the tenths of a volt) sometimes with soldered connections most voltage drop charts relate to copper or aluminum since those metals are the most practical to use from a cost/performance standpoint if low resistance is the goal solder is NOT a good conductor lead, tin and the other things we find in solder and some connectors can create a totally inaccurate measurement when trying to compare actual measurements to a wire resistance chart from a "good connection" standpoint there is no better connection than a "properly done high pressure crimp" where the metal is cold flowed solder is a substitute connection where a good mechanical connection is not practical or cost effective the research on this has been substantiated over and over again from the early days of the telephone and electrical power industries to the work done at NASA in the 60's to this day there is no electrical connection that surpasses a cold fused crimp for strength or conductivity try telling this to a car audio installer and his head will explode EXAMPLE # TWO someone mentioned the "skin effect" as a possible contributor to error since we are concerned with automobile applications here i think it is safe to assume that we are concerned with DC and not AC since skin effect only occurs with alternating current (the higher the frequency the more the affect) and not with DC this seems like a silly thing to even mention EXAMPLE#THREE someone mentioned that bigger wires helped ease the load on the alternator WOW! where do i even start with this one? if you want to make things easy for your alternator you need to put the smallest wire you can put on it that doesn't melt now i'm not saying thats going to make your electrical accessories work better but it will sure take a load off your alternators back a smaller wire (ie higher resistance) isolates the alternator from the load and serves to limit the current the alternator can produce at any given voltage output not a good idea but it illustrates the genius in that line of thought EXAMPLE# FOUR someone added up all the fuse sizes in the fuse box and somehow came to the conclusion that a nominal load in a GN could reach into the 170 amp range i once put a moderately modded GN with lots of accessories on a chassis dyno (to do this test on the street would have been impractical) and did measurements to see what kind of load really existed since the car was stationary i could do what was impractical when it was moving i had several people operate virtually every accessory while the car was running at 65 miles an hour coolant fan, high beams, wipers, AC blower, power seats, CD player with large amp, XP pump, window defogger, emergency flashers, power windows ect etc it was virtually impossible to exceed 105 amps no matter how hard we tried a simple understanding of how fuses work and how engineers select them for use in a circuit would easily clear up this silly notion need something to ponder? go to the fuse/breaker box in your house add up all the fuses and or breakers then check what size service you have just did my house for kicks total breaker amperage not counting the 200 amp main = 635 amps yet i have a 200 amp main breaker and service and the power company wire is appropriate for 200 amps i have lived in this house for 32 years with no electrical issues should i call the power company and recommend that they could ease the load on their nuclear plant if they ran wire sized for 600 amps to my house ??? from the comments on this ridiculous thread i could come up with a dozen more exampled of electrical misunderstandings/voodoo but i will leave things as is only to make a point the great thing about electricity is that is a useful servant for virtually all of us no matter if it is understood or not one thing is for sure there is virtually NOTHING about it that is not understood by some i don't claim to know everything either but if you are disagreeing with me about electricity there is almost virtually zero chance you are right................................RC
 
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