Wow that's quite a difference!

What would you suggest For coil wires?

I would simply install an entire set of new spark plug wires from NAPA. This will include the coil/distributor wire. That is what I have on my car and they work fine. I think the cost is pretty modest. Something like $24. While at it install a new cap and rotor on the distributor. The better NAPA parts for the slant are MO-40 for the cap and MO-3000 for the rotor. I am using these and they work noticeably better than the stock rotor. The MO-3000 has an extended tip, so it is best to make sure there is clearance inside the rotor by spinning the parts together and checking for clearance. If you are afraid at this point to remove the distributor, or do not have a spare, then just get a stock rotor. It will work OK.

MSD makes a nice set of 7.5mm spark plug wires that are shielded for around $45. The are universal, which means you must cut the wire to length and install the boots, but the set includes the crimping tool, which is nice. And, (this is big) it includes both straight and 90 degree connector boots for the cap connection. This will allow you to route the spark plug wires away from the fender and each other. It is common for the slant spark plug wires to wear clear through and short against the inner fender, thus shorting out and creating a miss. My local Pep Boys stocks this set.

Here is a tip that will make your life easier. Get a label maker from the office supply store and start labeling your wires, especially the spark plug wires when you install new. Just print out a length of number "ones" for instance, and then wrap that around the number one wire etc. You would be amazed at how many experienced techs have gotten the spark plug wires out of order and wanted to pull their hair out looking for the problem somewhere else. Good luck.



Sam

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Yup, those voltages are on the high side indicating that voltage regulator is most likely seeing low voltage in ignition circuit caused by corroded connections, and old worn switch contacts.

As Sam said, you need to find which component or components are adding resistance to the ignition circuit and repair, or renew the connection and or conductors. These increases in resistance are additive in a series circuit. Don’t forget to clean battery terminals, grounding conductor where it connects to block, and the ground from head to fire wall.

Next to be sure all components in ignition circuit are at the same potential by running a ground loop picking up spark controller & voltage regulator cases or chassis, alternator case, and negative battery terminal. This method will often eliminate voltage drop in the ground side of the circuit. When testing for voltage along circuit, always use the same ground location such as negative battery terminal.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Good advice on the ground loop Bill. Grounding the alt case is an often overlooked detail.

Sam

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Ok, I am going to have to do some studying for a minute or two...its like Spanish class all over again

What is being advised is make a wire connection from the alternator case to one the mounting screws on the spark control box, to one of the volatage regulator mounting screws, then to the ground post on the battery.

Richard

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Part of Tyrde-Browne Racing

Dave sorry, I don’t know about Spanish class, but Latin was Greek to me, and I suspect my explanation that Fopar translated correctly ranks right up there with Spanish.

Chassis, chassius, chassioirum…. Whatever… LOL… My brain’s now on fire just recalling those days.

I use the term chassis as one would regard electronics of yesteryear. Back in the day when radios and TV’s had all their bits, and pieces mounted on a steal platform, AKA Chassis, its function was to act as the earth, or ground in the system.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

I am pretty sure it's not the explanation, but my lack of knowledge in this subject, but thanks for the clarification Richard.

I think I follow now, I'm making a ground loop in order to have all these components grounded equally(?) This way when I test the individual components in the ignition circuit, I can see more accurately which one(or which area)may be acting up?

[quote]I think I follow now, I'm making a ground loop in order to have all these components grounded equally(?) This way when I test the individual components in the ignition circuit, I can see more accurately which one(or which area)may be acting up?[/quote]



By George I think you have it; connecting all the frames, chassis whatever one wants to call the outside of a widget where it bolts to the car with one wire back to battery puts all these devices on the same playing field, electrically the same, or same potential.

I try to explain this electrical stuff so someone not familiar with the jargon can understand. For example “Potentialâ€￾ is what the volt meter is showing between two points in a circuit. If you measure voltage between chassis of voltage regulator, and negative battery terminal and get 0v than both points have the same potential, or they are not connected. If on the other hand you measure the same two points and find +0.5 v than those two points have a different potential, in this case this would be voltage drop of 0.5 v caused by resistance between the two points.

This resistance can be from loose connections, corroded connections, high temperature, length of conductor, and or too small wire gage. Check out [url=http://www.the12volt.com/ohm/ohmslaw.asp]Ohm’s law[/url] to see how the three components of electricity inter act. This maybe real boring or an interesting topic, but something we need to be aware of when messing around with our car’s electrical systems.

Bill

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC