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CASH For Assistance - From Scratch Wiring Dilemmas


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No offense taken....But ... I am the ignorant one who knows nothing. The guy w/ 38 yrs Aviation experience is Rolland who has been helping me. Two separate people.

Stan: I am surprised at what 240Hoke said about EZ wire. "use different amounts of copper strands". This is NOT GOOD. Not to worry Stan, the hand drawn schematic/wiring diagram done for the cooling fan has a separate 1 amp fuse for the relay coils. This fuse should be as close to the relays as possible. I worked at Learjet and we had a model 35 aircraft that for some reason burned a wire, which should NEVER happen in an aircraft, and all it needed was a fuse or circuit breaker in the relay/solenoid wiring. But this would be a hidden fault if it blew, which again should NEVER have in an aircraft. The head of engineering poo-poo'd same. But I never did and also found multiple bit of bad engineering in other circuits which I was not allowed to fix.

 

Being in aircraft engineering, I really know about wire size and current carrying capabilities and causes of electrical fires. I follow aircraft accidents very carefully. I come up with my own best synopsis as to why things happen.

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Rolland, thanks for the clarification. I contacted several of the [big] harness manufacturers and asked the same question "what AWG wire do you use for XXX circuit ?" They virtually ALL used at least TWO AWG 'sizes' SMALLER than every book that I have [recently] read. Some of the circuits that invariably used too small a AWG were Starting and Alternator circuits, among others.

 

I have posted on this finding more than once over the years on threads, since so many [threads] pop-up [in duplicate] again, and again. I have read about pending legal action against some 'kit' manufacturers for that very reason [presume resulting in damage of some sort].

 

Many reply saying that I worry too much, or that they must be good since they sell so many. I choose not to be a sheep, and follow [only] because so many others do it. Which is NOT a specific accusation by the way to those reading this thread. It is a generalization to illustrate a point. And, for worrying too much ... I spent a whole summer on a showcar build when I was younger. It had been complete maybe a couple of weeks, when I had a catastrophic electrical fire, resulting in the [literal] meltdown of the car ... right before my eyes !! I had just finished detailing the exterior, done some wiring to the stereo system, and gone inside for lunch. Came out when my house began to fill with smoke, and the car was ablaze IN MY GARAGE !!!

 

In retrospect, I surmize that what had happened was that there was an arc of some sort in the wiring that I had just done on the sound system, which ignited the glue under the carpet that I also had just sprayed. KABOOM !! Big flames !!

 

Since that event, which was more than 20yrs ago, I NEVER want to under-engineer ANY vehicle electrical circuit. I would much prefer extreme overkill engineering than to go through a fire again. If they are mutually exclusive events, fine. But, I have TONS of wire, and too much time, so I would rather take two extra steps to really ensure that it eceeds virtually any standard.

 

Rolland, my Father was an airline pilot, and my closest friend is a 30 yr jet mechanic at LAX [AiResearch ?? formerly Garrett ??], so I understand what you were saying about that Learjet. MANY lives are at stake with aircraft safety, which explains the [in most cases] rigid standards. I prefer to [almost] engineer my car to the same standard of accuracy, especially in the matter of electrical.

 

I am also aware that there are MANY grades & qualities of wire, separate from the AWG issue. I try my best to ensure that I am using QUALITY grade wire, often marine-grade, tinned wire. Ironically, when I pulled some harnesses off of luxury cars at PnP, when some of them did have a label, they were made in CHINA !!! This, on Lexus, Acura, Inifiniti cars !! I was shocked. EVERYTHING that I have read and/or assumed was to avoid Chinese wire at all cost. Who knows at this point ... ? Best that I can do is make an effort to be safe, and use quality components; but, some things are beyond my [reasonable] control .... just like Rolland, and his shift manager who denied his efforts [been there - done that ... worked for those that say 'Git Er Dun' ].

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Stan: You had a real life experience with fire. These will OPEN your eyes wide open to the possiblities. I have been an aircraft owner 3 times over. I actually worked at AiResearch at the LAX airport under contract. It was my first job as a designer/engineer. What an experience. The fellow I was replacing left the MOST difficult job for me on one project aircraft. I solved it and came out smelling like a rose. My boss at AiResearch was one GREAT fellow and had a drawing system that was second to none. I learned it well and everything since then about wiring diagrams will never compare to it. Then I went to Learjet and what a let down.

 

Getting back to wiring, TXL and GXL are similar in makeup to Mil 22759 which is what we used in aircraft. TXL has a thinner insulating jacket than GXL. I worked in the Santa Barbara area for a fellow with very strict wiring rules. He rightly maintained that what ever power wire we were going to put in the aircraft MUST pop its circuit breaker when grounded at the very end same. This is BY FAR the best wiring rule that I learned. FAA Advisory Circular (AC) FAR 43.13 has a wire length versus gauge, current, and heat rise in the wire that is very good. I still maintain all these FAA ACs on my computer.

 

The Datsun wires in my 240Z have much fewer strands than american made wire.

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My engine bay harness is complete [LS1], although I have yet to finalize the BEST way to handle the draw of my Lincoln 18" [not 17" Taurus] fan. I have to wire from headlight to tail light, again, with the exception of the engine bay. I have made three 'project boxes' that house 48 circuits for fusing, and am completing my second project box to house ten tab mount relays.

 

I am open to ANY solutions. I am just too desperate to get it on the ground [in case I lose my house :~( ]. If you have a circuit board in mind, I am open to all alternatives. My soldering isn't bad at all. But, a jet aircraft mechanic friend of mine highly enouraged me to avoid soldering connections in main wiring runs. He isn't comfortable with relays, etc on 12V applications, so his assitance has been limited to more 'cosmetic' aspects.

 

Both of you guys are ENCOURAGED to PM me to discuss further. Thanks !!!!!

 

message me regarding your fan

i can help you out with a schematic i drew in fine detail.

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Well, I've seen cars burn down due to faulty electrical components. I've also wired cars or just engine bays from scratch. Just turn the dial down on the ranting and pick one thing at a time. Ask specific questions (as much as you can) and we will help you "spread the load".

 

I know you don't want to use Painless kits (which is fine), but if you need any more wire, they make good quality stuff. (this comment is mostly for others reading the thread that are behind you in preparation) They have good jackets and high strand count.

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Does anyone who might have read this thread have a 280Z, and have ever traced their Windshield Wiper circuit down completely ? The circuit has a component referred to as a 'Intermittent Wiper Amplifier' containing seven wires, including a ground wire.

 

Because I am using column controls from a 280Z, it would be helpful if I knew where this component was located on the car; and, try to find one at the jy. Wire colors coming out of it should be: Yel/Grn , Yel , Blu/Wht , Blu/Yel , Yel , Blu/Red , and Blk.

 

Thanks...

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Looking at my 1977 280z service manual, intermittent wiper amplifier is on the relay bracket next to the ignition relay, above these two will be the rear defogger relay-on the interior passenger side, right above the fuse block.

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That's all it is ?!? I thought that it would be some sort of metallic assembly with wires coming out of it [sort of like a miniature (old style) voltage regulator housing]. It is nothing more than a relay ? Is it possible for you to identify the specs on it ? My 280Z schematics printed from Autozone just show it as a 'rectangular' box.

 

Regardless, thanks for the info.

 

Then again, since you replied, I pulled out that Autozone Schematic, and it shows TWO Blu/Yel wires going to the Wiper Switch [from the "Amplifier"], which seems unlikely. So, now I question that accuracy of the schematics .... ? The 240Z schematics that I printed, prior to acquiring a factory Service Manual from 'FleaBay', did match the factory schematics in the book.

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That's all it is ?!? I thought that it would be some sort of metallic assembly with wires coming out of it [sort of like a miniature (old style) voltage regulator housing]. It is nothing more than a relay ? Is it possible for you to identify the specs on it ? My 280Z schematics printed from Autozone just show it as a 'rectangular' box.

 

Regardless, thanks for the info.

 

Then again, since you replied, I pulled out that Autozone Schematic, and it shows TWO Blu/Yel wires going to the Wiper Switch [from the "Amplifier"], which seems unlikely. So, now I question that accuracy of the schematics .... ? The 240Z schematics that I printed, prior to acquiring a factory Service Manual from 'FleaBay', did match the factory schematics in the book.

 

I cannot confirm that it is merely a relay just yet, but a relay could be called an amplifier. That's essentially what it is; feed it a low amp signal and it can spit out a larger amp signal, etc.

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I wouldn't classify a relay as an amplifier. it needs the higher amp signal to redirect the higher amp signal once the low amp tells it to.

 

therefore you are "relaying" and not "amplifying", so to speak.

 

but I know what you mean.

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Still a bit confused as to whether I need to try to hunt this piece down at jy, since I am now using 280Z column controls. I am also using the Honda Civic wiper motor ... if that makes a difference.

 

On to a different topic, since our cars are [relatively] small, it is crucial how close a relay or fuse is to the item that it is operating/protecting ? [e.g. the distance from the fuse box and/or relays to say, the fuel pump or the electric fan] Is it important to have the fuse or relay close to the electric fan?

 

Thanks...

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On to a different topic, since our cars are [relatively] small, it is crucial how close a relay or fuse is to the item that it is operating/protecting ? [e.g. the distance from the fuse box and/or relays to say, the fuel pump or the electric fan] Is it important to have the fuse or relay close to the electric fan?

 

yes and no.

 

you sound like this is your first time dealing with wiring, and i think the fact that you're asking these questions is great, because a lot of the time they are assumed and neglected and further down the line people who search for this because they think these questions are dumb is gonna stumble on this thread and it's going to have alot of good info...

 

always ask questions. good stuff.

 

to answer your question, the thicker the conductor the more voltage drops off as the wire gets longer. Never go by wire thickness as it feels with the insulation... you must look at the CONDUCTING WIRES inside the insulation. Look for a "wire amperage gauge chart" on google. it will show you what wire conductor thickness you need for certain amperages... use a wire that is rated for 5 (upto 10) amps more than required. This will make sure the fuse goes before the wire does. using anything overly thick will delay reactions from sensors that operate using a voltage like a steady 5 volts if your alternator is struggling to keep other things running at full speed.

 

also, it adds weight.

 

in reality, general automotive wire and a fuseblock up near where you can access it is best. you don't need to position fuses all across the car in different locations... BUT if it will make it easier, sometimes it's not a bad thing, as long as you cover them properly... remember where they are, and make sure they won't burn up.

 

and when choosing wire, take note of where it passes through. if it's going from a rubber tube into the door jamb so that when the door closes and opens, you still have a connection, then make sure there are MORE WIRES in the insulation, that are THINNER so it's more flexible, as opposited to LESS WIRES that are THICKER to make it more rigid (like battery main wires).

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