I had a 1972 Dodge Dart I bought new. The electrical system in general was designed by monkeys. I was warned early on to keep a spare ignition resistor in the glove box as these fail without notice and leave you stranded. It seems Chrysler chose to run the ignition system (points) on 6 volts and the rest of the car on 12 volts. Why on earth they did that is beyond me as all other makes used 12 volt systems.
I think averagejoe72677 may misunderstand the function of the "ballast" resistor in conventional ignition systems. First, it was used by virtually all auto makers since the sixties and was used to make starting easier. When cranking, battery terminal voltage for a "12-volt" battery can drop to 6 or 7 volts ... the load during cranking can be several hundred amps! The ignition switch bypassed the resistor during cranking so that a good spark could be produced by a nominal "6-volt coil". Once the engine was running, the resistor (typically about 1 ohm or so) was back in circuit - to avoid overheating the coil and burning the "points".
No argument about the stupidity of assuming mechanical fasteners automatically have good electrical conductivity. I've seen hundreds of Chevy tail-lights that didn't work because they used the clip that mounted the socket for ground contact. Some old headlights made the same mistake. More electrical engineers (make that good electrical engineers) need to inspect and approve car designs!
I had a 1973 Duster, w the famous slant 6, which was a hand-me-down from my father. The problem I had, when the car was about 15 years old, is that the column shifter wouldn't stay locked into Drive. Being disinclined to disassemble the whole steering column, I never figured out what the minor part was, that was holding the thing into the detent.
I had the 73 Valiant with the slant 6 which was handed down from Pops in '76. I had a bad motor starter after a few months at school. Crawling under the car and hitting the starter with hammer worked for a while but finally I bought a rebuilt starter. When that starter started to fail a few weeks later I took it apart on the kitchen table. Not seeing anything wrong, ( like I would know) I reassembled it with some difficulty. I installed the starter and it worked fine. I was quite sad to see the next day that a retaining collar and spacer had fallen off the table and were not back in the starter. The starter worked fine without the missing parts, I sold the car in 79'
The fact these cars are easy to work on shows in the photo as the owner of this Scamp must be having a lot of fun with it. The engine compartment shows a lot of modifications from stock. Aftermarket valve covers and spark plug wires, Carter Competition Series 4 barrel carb on an aftermarket aluminum intake which necessitated the mounting of the coil on the firewall, the windshield wiper motor has been removed. A fuel pressure regulator is mounted on the inner fender panel which most likely means the car has an electric fuel pump feeding it. The heater has been bypassed or removed because the hose which typically feeds it has been rerouted to the intake manifold. This car isn't your typical "grocery getter" anymore!
I had a Chrysler Horizon the first year that they were made and after having front wheel bearings replaced six or sever times (every 1500 miles), they finally sent a top guy out to check the car. What they found was that the ground strap from the starter to the frame ground was missing and every time the car was started all the current went through the wheel bearings and cooked them.
1973 is before my time, but did any of the automanufactures use star washers that much? I would expect a flanged bolt to be used on the inner fender apron. That's the way my 67 Mustang was done. Body clips and flanged bolts is what is on a mustang. I think star washers are kind of a new thing. And.. wouldn't the engine ground strap take care of this? Mustangs are front of block to right-hand frame rail.
I worked at Chrysler during that era and the truth is that the purchasing folks did what they wanted, which often included reducing costs by purchasing materials that were less expensive than what the engineers called for. Probably the single bolt holding the voltage regulator was touted as holding tight without needing that extra lock washer, with no mention of the electrical connection properties. I had a similar problem, except that the poor connection was on the large post of the starter control relay. That split lockwasher did not keep the connection quite tight enough, and so the charging system dropped a volt between the voltage sensing point and the battery, resulting in a chronicly undercharged battery. The solution wound up being remembering to tighten that nut every few months. That was OK because I did my own car work. Pity those who had to have somebody else do it for them!
After reading the story some question arise; I have read the posts listed on the electrical issues on the 1973 Plymouth Scamp. This sight has always seamed to be above some of the careless biased stories that I have read in years past from other sources.
I have worked on Mopar vehicles and other vehicles from a variety of other OEM;s for over 30yrs and have sean many strange items so I never say any particular failure is absolute. That being said.
Yes the electrical wiring and systems on early 70's cars were not weatherproofed very well and compared to today's sealed connectors and routing which are much much better.
But this was an issue with all cars back in the day. Domestic and import.
Reading the same old naritive; According to the author about buying an americain car and then having these terrible quality issues with no talk about any issue on the preffered imports seams a little fishy.
Some one should have done there home work about the type of typical repairs to this perticular design of charging system. Chryler used this system for many years in all there vehicles from the early 70;s to the early 90's.
Your diagnosis seams to be a bit faulty and the assumptions stated are just plain wrong.
First the Altanator field windings are grounded through the voltage regulator so if the ground is lost the altanator would not charge not over charge.
This typical failure had a number of root causes.
Faulty Voltage Regulator; simple to replace and follow proper installation instructions point to making sure the bolts / screws to the firewall surface is clean and have good contact.
Faulty wiring with short to ground of the field wires this wire was typicaly a grean color wire to the regulator gounding it will cause the Altanator to max charge output.
internal short of the alternator to ground which also causes max output.
Next the voltage regulator always has atleast 2 Bolts / Sheet metal screws and typicaly having star washers and or serated flange bolts included so either the car was used and had a poor repair previously or were not installed in production and after seeing thousands of new cars I have never seen just one bolt / screw. fastening the regulator from the plant that is why there are 2 to 4 holes per voltage regulator.
My 1971 Plymouth Scamp rusted to death as its mileage progressivley failed due to the heavy amount of bondo on its quarterpanels. It did have a black vinyl roof that outlasted even far better luxury car roofs and still looked darn good years later with just a fresh application of vinyl renew. Like a cadaver with boyish looking hair...
It's oversized compressor could put out AC to freeze ice cubes, even in the hottest of weather with a black interior. When the compressor would kick in at an intersection the pedestrians would jump. I could get the slant six to run siliently by adjusting the valves, but that was only good until the first spin around the block. It dropped oil like BP does in the Gulf and had its own little plastic parking pad in my driveway that had to be wiped every week or so.
It was the last car that I could fix using a flat head screwdriver and an adjustable wrench. It bested a later model Chrysler Cordoba that rear ended it and the Scamp left the Cordoba in tiny plastic pieces all over the road, suffering nothing more than a chipped chrome finish.
Never had the resistor issue though, perhaps because it was a 1971 model and the beancounters had not yet gotten around to ridding it of the star washer. My wife had a 1972 Plymouth Valiant with similar traits and she got quite good at fiddling under the hood to fix whatever ailed it. You could fix just about anything under the hood in about ten minutes! I STILL see one or two of them around the area and they still run, no smoke!
What I can tell you from looking at this post is that the only Monkeys at work here were the ones who modified the living H out of this poor car. And a lot of it involved mods to the electrical system to make their hacked up mods work.
Having been a gearhead from conception forward I can tell you that less than 1% of those attempting to zoop up their coupe have a clue about how to actually do it without trashong the rest of the car.
And from what is visible here, these cats are among the 99%. And more often than not alcohol combined with simple ignorance is a contributing factor to the disaster.
I still have my '73 Dart I bought new in January of 73 and its electrical system is still fully entact. And it runs high 12's
So don't blame the car or Chrysler, think things through and spend a little time with one of those 1%'r's.
It isn't that repairs to one of these cars is an overwhelming task: The problem here lies in the modifications attempted. Google a few images of the engine compartment of a few of these in stock dress to compare to what is in the post picture.
If you look, and not even very close you can see that there is little visible that came on the car new and what might have has been relocated in such a way that the wiring had to be modified to accomplish the task. Most of what is visible probably came from Jegs or Summit Racing and was installed with little or no thought given to purpose or functionality.
It is very possible to make substantal mods to one of these and have the work come out clean with a nearly stock appearance.
I guess this post put me on a bit of a rant. After 45 years tuning and seeing messes like this and hearing them blame anyone but themselves for the ensuing problems just strikes a sour chord with me.
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