[SNYP40A1]

I have looked at the wiring diagrams and even though I have a degree in electrical engineering, I find them confusing to trace through. I am rebuilding the electrical system in a friend's challenger which is being completely rebuilt and "enhanced". However, I think I want to start from scratch in hopes of making a simpler and more efficient electrical system. I do not plan on wiring many of the components in the car. For example, the car will not have a stereo, no air-conditioning, no wiper fluid cleaner, etc. My friend plans on using the car for racing and only wants to power the necessities. The battery placement is also different, battery will be in trunk for better weight distribution. So the stock harness will not work anyway. I am confident that I can build the wiring harness myself, but I need to know the electrical properities of the devices that I will be supporting. For example, what are the inputs of the windshild wiper motor? What type of signal is supplied to the motor to make it wipe? What type of signal does the horn require? I have to figure that there are kits which integrate most of this for hot-rod cars. I do not wish to keep the origional wiring as I think it can be simplified. I just find the wiring diagrams over-complicated, what the hell does L3-16R mean? I don't understand the pin connection boxes either. They number the pins, but do not show how they are connected. I feel like the diagram is too cut-up. I would rather understand the wiring in terms of the input signals required by each device. Anyone have any suggestions? Is there a place for modern generic hot-rod wiring kits?

[dave-r]

Not sure what you mean by types of signals? It all works on battery voltage. Maybe it's a language thing?
Only the tach and electronic ignition use a "signal".

The wire codes are explained in the "Key". The bulkhead connector (back of the fuse box) is where most of the diagrams terminate.

Being a Hot Rod I am suprised it is using ALL Chrysler parts.

However you have come to the right place. I have simple diagrams (or I can draw some) that you will be able to follow for each individual system.

If you do not wish to make your own harness then Painless Electrical make universal Hot Rod wiring kits that include full instructions and everything you need.

I will get back to you with the diagrams.

[fbernard]

Like Dave said, Painless wiring makes modular harnesses that are way better than anything that an amateur (even an engineer such as you - or me) can reasonably do. Especially in terms of connectors.

Another very interesting spot for wiring info is the tech section on http://www.madelectrical.com
This site gives a lot of details on common mopar drawbacks, which you'll get rid of by not using the original harness.

[dave-r]

I don't need to supply any easy diagrams for you because this great book already has them!

http://www.amazon.com/exec/obidos/tg/de ... ce&s=books

I forgot I had a copy myself. It is a very good book. Great diagrams and very easy to follow.

Also Painless are researching a Mopar specific wiring harness at the moment. Hopefully it will be out sometime early next year.

[itsfred]

i think what he means is do they switch the neg or positve side.
the horn button is switched neg side , ground to the horn relay.
wiper use a combination of switched power and applied grounds.
SNYP40A1 if you need help i have done both, modified original and home fabricated harnesses. email me
fred

[dave-r]

OK gotcha.

[Jon]

If you are getting rid of the old stuff would you give us vultures a shot at it? The parts must be a living working thing though.

Jon

[SNYP40A1]

Jon:

Whatever I no longer need, when I am done, which will be about 3 months or so from now, I will post the extra parts that I want to get rid of on this board and people can claim.

Dave-r:

"Types of signals" I suppose was badly-worded. What I really meant was generally, what types of electrical inputs are needed to make the device function. For example, a horn, 12 V, 1 Amp = on? 0 V, 0 Amp = off? Or does it need a 1000 Hz sinusoidal signal with +5/-5V peaks? Windshild wiper, how do I make it swipe? +12V up, 0 V down? I am not really sure. But I think that if I did know, I could design a more efficient electrical system using modern components and not have to worry about the components that my friend is not including.

Painless is a good idea, but I can get all the wiring parts, including connectors for free and immediately (friend has a connection). (I am talking about modern wiring of course, not origional).

Thanks for all the help. So I guess what I am looking for is more information about how the devices that I am using work, such as:

Ignition switch (2 positions: Accessory, Start)
Starter
Alternator
MSD Ignition
Electric fan (with thermostatic control)
Horn
Left Turn Signal
Right Turn Signal
L & R H.L. (Low beam and High Beam)
Marker lights
Turn Signals
4-way Hazard light
Brake lights
Wiper motor
Electric Fuel pump
Tachometer, Speedometer, water temp, oil temp, oil pressure, fuel level, trans. temp

That's it. The hardest part will be installing the new (non-original) gages. Most of that list involves installing the lights. The lights require a simple signal, 12V = on, 0 V = off, just need to make sure that the relays support the required current and that the wire is of the proper thickness/resistance. But in terms of how the brakes actually work on the electrical side -- what makes the brake lights turn on when pressure is applied to the brake pedal, this is what I want to find out. For example, what type of device is responsible for translating applied break pressure into an electrical signal (not a complicated signal, just DC). Or maybe the brake pedal sensor just changes resistance as pressure is applied to the brake. I don't know. I don't need to know how the brake sensor, for example, works at the physical level, I just need to know its output characteristics. "What does it output when brake pedal is pressed -- what does it output when brake pedal is released". Stuff like that. Dave-r, does your book explain stuff like this? If so, then I will just buy the book and save everyone the trouble of explaining this stuff to me.

[dave-r]

Yup. That book expalins the lot. I can't think of anything it does not cover. It lays out each Mopar, Ford, and GM system.

Ignition system, charging system, lighting etc etc.

You will find most everything works with a plain 12-14v positive feed. Almost everything grounds via the chassis as the return path. Things like the wipers work themselves because they switch internally. They just need 12v or a feed from a vairiable voltage output speed control. No frequencies are involved.

Some of the dash guages work on 5v or something like that. Chrysler use a primative on-off regulator to get that.

Honestly. That book and the mad electrical web link will give you everything you need.

[fbernard]

For example, what type of device is responsible for translating applied break pressure into an electrical signal (not a complicated signal, just DC). Or maybe the brake pedal sensor just changes resistance as pressure is applied to the brake. I don't know.

That is usually a switch to ground (grounded when the brake pedal is depressed). Same kind of switch that is also used to detect door or hood opening.

[SNYP40A1]

Sounds good guys, thanks for help. I shall come back if I have more questions. fbernard, I love the quote on binary

[SNYP40A1]

I have another question actually. Where is a good place to buy automotive electronics online, like flashers, power relays, etc.