Continue to troubleshoot or start from scratch?

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Bl1zzard

Bl1zzard

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I've been working on my 1974 Dodge Dart Swinger since buying it non-running last October. It was a slant 6 but the previous-previous owner swapped in a 360. As far as I can tell he never finished the project, so it's never run. We've got all the pieces and were ready to see if she would start. Got a new battery, hooked it up and tested a few circuits, headlights check, horn check, brake lights check, oil pressure dummy light check, so far so good. I decided to give it a kick just to see if we had cranking power. Nothing. I'm able to short the starter relay and it cranks. But I started to check for voltage at the coil, 3 volts. Ballast resistor got real hot real fast so I shut off the power. Started checking for shorts and ground. Seem like everything is shorted to ground, both coil wires, all the pins on the electronic ignition module, the ballast resistor, both field wires on the alternator, seems like every wire and connection I check is grounded/shorted. Damn, I don't even know where to start. Looking closer at the wiring, there are a number of plugs not connected to anything all go straight to ground. Question is, should I keep troubleshooting or start from scratch and replace the harness?
 
Unplug everything.

Pick one, plug it in, see what works, see what gets hot. There are three connectors at the bulkhead, grease them and see which one is under hood, one is interior, and the other is other stuff. I'd start by plugging one, then another, then the last, and see if anything goes crappy. Then hook up one thing at time. Brake lights are easy, they have power all the time due to hazard light switch.

This is also your chance to INSPECT EVERY CONNECTOR FOR SIGNS OF HEAT OR MELTING.


Keep going till you get your problem circuit. Fix that.

Also, your starter issue could be your neutral safety switch.
 
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When you say "shorted to ground" you may be leading yourself down a rutty road. If you are using an ohmeter, just because these circuits show continuity / some value of R does not mean that they are "shorted."

But I would agree^^ to unplug a few things until you start to see come pattern/ thought continuity

As far as cranking.............you likely have the annoying "seat belt interlock" device which disables the cranking signal. The functional path is (battery etc to the ignition swtich) ---twist the key to start---crank signal out of the ignition switch on yellow---through the bulkhead connector----to the seatbelt reset device---out of the device---to the start relay---through the relay coil----out the neutral safety terminal----and (depending on stick shift or automatic) either to the clutch safety switch on the pedal, or down to the automatic to the center neutral safety switch terminal---and grounds when in park or neutral
 
As far as hot ballast is normal. Do NOT leave the key on for long without the car running. Hard on the ballast, coil, and ignition box. There is a connector at one end of the ballast with a jumper ---2 of the pins are jumpered to gether. With key in "run" you should have "same as battery" there. The coil normally sees somewhere between 6 and 10V when sitting stopped "key in run"
 
i don't know about darts, but 74 dusters was 1st year mopar put a seat belt interlocking module, its a ivory colored plastic module next to fuse panel, it just unplugs, you need to check it for corrosion, mine was wet and corroded, you can't just cut it out, it controls 11 different things ,from dome light, dash light, turn signal, parking lights and several other things, and under the hood next to the washer bottle there is a reset button with 3 yellow wires that has to be by passed if you don't have wire going under seat that detects someone sitting in it. They have a green module and a orange , one from Canada and one from cars in Venezuela ,because they had no seat belt laws,and are bypass modules, but on ebay they go for about $150 . After 6 months trying to get my duster to start, i finally stripped all the under dash wiring and bought all the under dash wire from a 71 dodge dart and got rid of module, only $50 for wiring, then i rewired the reset button on the fender well under the hood and done away with the reset button. The modules caused so much trouble that Mopar quit using them in 1975. may not be your trouble but will give you an idea should you have the ivory module in your wiring harness. By the way i was doing a 6 to 318, so hope this gives you a clue, mine would start from crossing at relay like yours, but could never get the key to work until i change wiring and if you have 2 plugs hanging down , it could be that previous owner unplugged interlocking seat belt module, i found 8 or 10 ivory ones, but if you take the plastic off the modules most are white where moisture has taken a toll on them sitting for 20 and 30 years
 
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67Dart273, you may think its not true, but as Bill Cosby says the (PROOF IS IN THE PUDDING) i dealt with the above problem 6 months, the U.S.had white or Ivory, if you sat a bag of apples in the passenger side seat that weighed 40lbs or more , the car had a sensor under each person the belt had to be buckled, you could unplug them under the seat and not worry about the module, but you still had a switch on the inner fender that had 3 wires , all yellow, one with a black tracer that had to be wired on bypass in order for the car to start, if its not true ,go to ebay and you will see green modules, these were put on cars shipped to Canada, and automatically by passed the need for seat belts, the orange ones were put on cars shipped to Vezeuala ,also were no seat belt laws at that time, so Bl1zzard , if you don't beleive that ivory module controls 11 things by cutting the plugs off go for it, cut the plugs off and try to rewire around it, if its not true look at other threads on this site and you will see that the 75 and 76 dusters ,Chrysler done away with those modules because they caused so much trouble. All i have to say , IV'E BEEN THERE AND HAVE THE T SHIRT to prove it, one last thing if you use a different year model wiring harness , there is a little different at the bulk head, mine was the brown wire to the ballast and the yellow wire to the starter relay go out on different letters than the 74 model. I wasn't trying to say definely that seat beat module was your problem, just giving you an ideal of possibility of things to look for now and in the future should you have trouble,but you made mention in starting thread about some connectors handing down is the reason i added this thread, until you have wrestled with problems like this, sometimes we over look thing, i thought maybe previous owner had tried to locate a good seat belt module ,and couldn't find one , i went to junk yards and pulled a half dozen or more and all were white with corrosion, so if this helps fine ,if not maybe in the future it will , but i located 3 other people that posted about the dreaded seat belt module , same section as this Aug/2/19, july/22/19, june/18 2019, and that was just the people that posted, but if Ma MOPAR done away with them, on the 1975 model, thats proof enough to me that they were crap from the start.
 
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Is people from Idaho the same as people from Missouri, are they called the SHOW ME STATE? LOL...make a post of possible trouble and get a colored 1973 mopar brochure touting how great their product is, but discontinued it in 1975 ? Just shows me that Chrysler engineers over thought the situation and made a pile of **** that we are dealing with 46 years later..
 
Thanks for all the suggestions and tips guys. I'll say that I'm quite sure that none of the wiring for the seats are connected and neither is the neutral safety switch. I know that because I had to install the upholstery on the seats and there were no wires to be seen. The neutral safety switch harness is not connected because it was taped up to the headlight harness. I'll have to start from way back at the beginning and see where it gets me. Thanks again for the advice, it gives me some good places to start.
 
Hi again, been crawling around the car for the last few nights tracing wires, cleaning terminals, etc. I unbundled the neutral safety switch harness from the headlight harness and fished it down to the transmission. Jacked up the car and crawled under. Having never hooked up a neutral safety switch before, I assume I'm looking at the right place, right below the shift lever. What I found there won't connect to the 3 prong plug I fished down from above. Any ideas what this is? It's a threaded stud with a nut on it.
IMG_20190814_192634.jpg
 
OK, I've discovered that is a single pole NSS after doing some Google sleuthing. My question now is, can I swap out that switch for the 3 pin switch and use the existing harness, or do I have to do some rewiring and just connect a single wire to the ignition relay?
 
Bl1zzard said:
Hi again, been crawling around the car for the last few nights tracing wires, cleaning terminals, etc. I unbundled the neutral safety switch harness from the headlight harness and fished it down to the transmission. Jacked up the car and crawled under. Having never hooked up a neutral safety switch before, I assume I'm looking at the right place, right below the shift lever. What I found there won't connect to the 3 prong plug I fished down from above. Any ideas what this is? It's a threaded stud with a nut on it.
View attachment 1715379226
Click to expand...


Bl1zzard said:
OK, I've discovered that is a single pole NSS after doing some Google sleuthing. My question now is, can I swap out that switch for the 3 pin switch and use the existing harness, or do I have to do some rewiring and just connect a single wire to the ignition relay?
Click to expand...

That is the 60's style neutral safety switch... Someone put the old style NSS in instead of the newer 70's style...

Order the correct neutral safety switch for 70 or later... Since you're working on a 74 car, look up a NSS for a 74 Dart...

However, be ready for some trans fluid may leak out when you remove it if the trans is full...
 
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