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-   -   Electrical Decay? TeamRush? Anyone hear of this? (https://forums.off-road.com/jeep-short-wheelbase/116572-electrical-decay-teamrush-anyone-hear.html)

**DONOTDELETE** 04-18-2002 11:43 PM

Electrical Decay? TeamRush? Anyone hear of this?
 
I remember reading years ago...somewhere...that after a vehicle is 5 years old, the electrical resistance begins to build up through corrosion of terminals, damaged wiring, shorts, etc. I recall something like 10% increase for every year after 5 years....does this make sense?

For instance: If you had a 100 amp alternator, after 6 years, due to decay of the vehicle's electrical system...you could only use about 90 amps? After 10 years 50 amps? I mean....It kinda makes sense, but....what do you guys think?

-remy
(known for ridiculous thoughts....remember last weeks corded cordless drill?)

JimmyZ 04-19-2002 06:49 AM

Re: Electrical Decay? TeamRush? Anyone hear of this?
 
My $0.015396 is that I have never heard of any figures before. Any connection or switch contact is susceptable to corossion resulting in resistance if not properly done. I'm thinking of doing a Painless wiring headlight switch relay because of potential resistance in a 23 yo headlight switch. I'm gettin' older and the more light on the road the better. Splices can also be a problem if corossion gets between the splice and strands. In a Jeep's wiring harness there are only a couple of splices. They are nothing more than a crimped band. The hard part is finding them on the engine harness. Use a wiring diagram and trace the wires. If water wicks between the insulation and the conductor it will cause corrosion on the outside of the conductor but I think the only detrimental effect would be for stranded wire carrying A.C. Higher freqs. like to travel on the outer parts of a conductor, skin effect. As far as an alternator there might be some depletion of the elements used for the electronics causing an inefficienty, but I'm sure you know as well as anybody else here knows that when it stops working it stops now. Generally speaking if you have clean connections to begin with and have some sort of moisture barrier, Dow Corning makes a good dialectric silicone grease, the electrical resistance would be so slight that it would require a very good DVM to measure it and the good connection should be maintained for many years. BTW I have my eye on a used 12V cordless drill at work to setup the same as yours.

Brhino 04-19-2002 12:39 PM

Re: Electrical Decay? TeamRush? Anyone hear of this?
 
Generally speaking this can be true. But it is not a time thing I have worked on good 50 year old electrical equipment and bad new equipment. Electricity acts the same way wether in a car, at a power plant (where I used to work) or in your home. Bad connections are high resistance and limit the amount of current and voltage it can carry. I would not downgrade your electrical system because of it, but I do check my important connections yearly both on my car and in the home. Battery connections, engine block connections including grounds, starter and main fuse box connections.
There is a problem when looking at the quality of a connection with a DVM. DVM put out 9V (from the little batteries in the back) at a small current. They are really not capable of showing how good a connection is. There could be one little knub make a solid connection and the DVM will read 0 ohms. Put 100 amps across that knub and you will have a whole lotta heat and problems. DVM help, but do not swear by them. There are things called DLRO that measure in microohms and put out some current that are the real deal. They are $3-5k so not in your normal Jeep budget.
All in all, again check your important connections and do use the conduction grease, maybe blow out the dust from your alternator and give it a go.

**DONOTDELETE** 04-19-2002 01:05 PM

Re: Electrical Decay? TeamRush? Anyone hear of this?
 
Jimmyz and Brhino just about covered the basics.....basically which means keep it clean and keep it tight. As long as you have a good gas tight (this means air can't get in between the contacts) connection, then there should be no corrosion...basically, the corrosion is any oxidation that takes place....and even copper oxidizes...ever hear of copper oxide?.

So....in a nut shell....wiring does not degrade unless you get corrosion between contacts or somthing damages the wiring (like constant moving). The only other issue is to make sure you have good grounds...TR can give you a real good book report on this issue. And one of the reasons grounds are so important is because it's typically between two different metals which creates a whole new set of problems. Hell...there are engineers out there who specialize in nothing but grounding. That is why it is sometimes called FM.

Junk Yard Genius 04-19-2002 02:18 PM

Re: Electrical Decay? TeamRush? Anyone hear of this?
 
I think the subject has been covered, but there is one point I want to clarify...

It isn't that your alternator is putting out less amperage, it's that it's taking more current to blast through the crud...
What was a nice clean circuit that only took 'X' watts to power when new is now taking 'X' watts to power the device, and 'Y' or 'Z' watts now because you are powering all of the resistance and corrosion too.

You are loosing so much to the resistance from the corrosion, rust, gunk, moisture, ect... it takes twice as much current to power the device...
It's the same alternator you started with, but now your demand on it has increased by 1/3 or 1/2 because of all the losses to the support systems (wires, connectors, switches, ect.).

Why do you think I stand on my soap box every day and extol the virtues of Cleaning Connectors every time you take them apart and using Dielectric Grease in them?
Cleaning them makes a low resistance contact, and the Dielectric Grease keeps moisture and oxygen out of the connection...

How about Rosin Core (NEVER ACID CORE), Silver Bearing Solder for connections?
Silver doesn't corrode internally. Silver is the best conductor of electricity. Silver is more dependable than tin or lead. Silver self heals when the connection cools, and can be remelted if necessary with out damage.
Silver content will keep the dissimilar metals corrosion out of the joint.

How about Heat Shrink Tubing?
Heat Shrink isn't cheap by any means, but it's a great way to seal the moisture and oxygen out of a connection.
It's more trustworthy than 'vinyl electrical tape', it's easy to use, damn near fool proof, available everywhere, seals up connections better than anything I can think of , and looks good to boot!

How about Crimp Connectors...?
Crimp connectors are a blessing and a curse.
Crimp connectors save you the trouble of using solder to Tin the ends of wires, and keeps you from having to solder and de-solder connections all of the time, but they have their own problems...

Dissimilar metals will corrode when in contact with each other... If the terminal isn't say, made of copper like the wire you are attaching it too, (and most cheap ones aren't), you will have a built in corrosion factor as the dissimilar metals react to each other.

You can stop this with...
1. Solder. Silver bearing electrical solder (not silver solder) will stop the problem before it gets started.
2. Quality Connections. Use Copper connections when ever possible. Lots of connectors will have a tin, silver, or cadmium plating on them, but if you look closely at the edges where they were stamped out, you can still see the copper (like a quarter).
3. Oxidation guard. Like dielectric grease or RTV in a pinch. Squirt some in the connector before you stick the wire in and crimp it. This will keep the problems to a minimum, and delay the reactions for quite some time.
4. Don't use cheap wire. Use virgin copper wire, not alloy.
5. NEVER PIERCE THE INSULATION OF A WIRE!
I've seen those 'Poke-A-Hole' test lights, and they are a really BAD idea...
Use a wire, jumper, probe, ect at the terminal, but NEVER PIERCE THE INSULATION OF A WIRE!

6. Know the proper way to make a connection.
A. Crimp, Twist, Ect.
This is a MECHANICAL CONNECTION, not an Electrical connection.
You may have low resistance now, but with a bare, air gap filled crimp or twist it's not going to be long before moisture, oxygen and the electrical current have their way with the connection and corrosion starts in a big way...
B. Solder, this makes the electrical connection, and should be done after the crimp.
This doesn't make the connection 100%, but it will be a lifetime connection if you do the next step...
C. Protect. Use Heat Shrink, Tape, Liquid Sealant, Ect. to protect the joint.
Moisture, Oxygen and Electrical Current are the enemies, and you can't do a damn thing about the Current flow...

Mechanical Connection, Electrical Connection, Protection....

Jaffer 04-19-2002 10:20 PM

Re: Electrical Decay? TeamRush? Anyone hear of this?
 
A note about "Silver Bearing" solders...
These are "soft" solders with a melt temp.usually around 450* F. much like other "soft" solders.
They are labeled "Silver Bearing" and are usually an alloy of 4% siver with the remainder of Tin and/or Zinc.
They come in rosin core and are described as "for electronics" or are packaged with a bottle of clear flux, usually in a dropper bottle.

**DONOTDELETE** 04-19-2002 10:34 PM

Re: Electrical Decay? TeamRush? Anyone hear of this?
 
Thank you, Aaron. I was hoping you'd see this post, for I felt you could give me the excellent advice you did. I appreciate the time you took to reply. Have any idea why heat shrink is so darn expensive? I use it whenever and wherever I can, but that stuff isnt cheap! Whats it made of, gold? hehehe

thanks again,
-remy

speed_buggy 04-20-2002 12:38 AM

Re: Electrical Decay? TeamRush? Anyone hear of this?
 
about Crimp Connectors

Professionally, my biggest pet peeve is guys that don't use the correct crimping tool. For guys working on their own vehicle it don't bother me.

Crimp connections rely on a gas free bond. If air can get at the bonding surface then it will corrode (eventually). The dissimilar metals can't under go the oxidation process without oxygen.

It you squish a crimp onto a wire with a pair of pliers or with the 5 buck crimper you got at K-mart the connection will not last over 5 years, unless you got lucky. your bond may have pockets of air traped in it.

If you check out any of the spec sheets from AMP for their ring lugs, you'll see that they recommend a tool for crimping and the LUG will have a "UR" rating instead of a "UL" listing. This means that the ring lug is only recognized to meet electrical code requirements if used correctly. Which means to use the specified and calibrated crimp tool. they rachet so you can't half crimp them. They are expensive too.

Did you know that crimped ring lugs used to be a staple of the nuclear power industry. It took a lot of testing to get them away from ring lugs. And in Japan they wont buy any power equipment from you unless it's all ring lug.

Use crimps responsibly and they will treat you right.

Sorry, if this sounds pointy.. I had a bad day at work and just wanted to contribute.

Junk Yard Genius 04-20-2002 12:55 AM

Re: Electrical Decay? TeamRush? Anyone hear of this?
 
I guess it's not easy to manufacture (that's a guess only...).
I pay about $1 an inch for the kind with Glue in it (the best type to use),
and about $0.45 an inch for the thin kind with no glue (like Radio Shack and discount auto parts stores sell)

Anyone that's seen my harnesses know I don't cut corners (or hold back on the heat shrink).
It doesn't pay to cut corners when you are that close to doing everything else correctly...

<hr>
Just for the record, the only time I've read the term 'Electrical Decay' was in reference material about Super Cooled- Super Conductors... Something about Electron Decay rates when current is stored in a superconductor for long periods of time...

This is interesting for me, and I agree with the term for vehicle systems, but I'd change it to Electrical System Decay....
That's more accurate.

I damn sure agree with the principle!
I've seen way too much in the way of corrosion, and a multitude of other problems down through the years...
The factories are going to design the electrical systems to live through the warranty periods, and that's it!
With common fuel injection over 20 years old now, expect to see more cars in the bone yard from electrical problems than anything else...

Jim_Lou 04-20-2002 08:33 AM

Re: Electrical Decay? TeamRush? Anyone hear of this?
 
One more tidbit on the subject. Arron mentioned "RTV in a pinch." You might think that RTV would be perfect because it sticks well and is darn sure air tight. The problem with common RTVs is that they produce acetic acid as they cure, hence the vinegar smell. Acid of any kind is the last thing you want around wiring.

Dow Corning makes an RTV, product number 737, which is neutral cure and non-corrosive. Under the direction of an electrical engineer who worked on the Gemini capsules, I have used it without problems on 14 kilovolt power supplies and sensitive printed circuits. It is terrific but expensive; the last 3 ounce tube I bought was about $10 if memory serves, and it may not. You have to get it at an electronics supply house.


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