Need some help with diagnosing my car. Young guy learning

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littleduster225

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hey guys. im new here, i see around the thread alot of helping going on and was hoping you guys could help me with my first car. i have a 75 duster and its been acting up since i got it. there would be days when it simply wouldnt crank and accessories like radio and lights wouldnt work then they suddenly work again. that was a couple months ago now something similar has happened and it hasnt been fixed for days. ive replaced the starter relay and the fuses, and made sure the battery was good. tested with a new one but still nothing. hope you can help out. Any thing is much appreciated
 
My first suspect would be the firewall connector. It's a large black plastic connector on the driver's side kinda sorta under the master cylinder. I caint remember on that one, but it either has a bolt in the center or maybe a clip on each side. At any rate, remove it and closely inspect the brass terminals inside it. They are probably nasty, corroded and possibly even burned or meted. That's where I would "start".
 
RustyRatRod said:
My first suspect would be the firewall connector. It's a large black plastic connector on the driver's side kinda sorta under the master cylinder. I caint remember on that one, but it either has a bolt in the center or maybe a clip on each side. At any rate, remove it and closely inspect the brass terminals inside it. They are probably nasty, corroded and possibly even burned or meted. That's where I would "start".
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Same here with my old 71, it overheated and melted. Sometimes it died on me and I would have to jiggle the red hot wire. Ended up having the thing rewired.
 
I agree with RRR, youve got a bad primary connection someplace. also check that your batt cables are tight, not corroded, broken, etc and neg cable has a good, solid ground. Its a tedious process, but if you have to go thru each connection 1 at a time, sometimes thats the only way. an afternoon with a brass wire brush & WD40 can do wonders.
 
I agree with all of the above and will add that I've seen battery cables that look fine on the outside but when we split them open, they were green with corrosion. Sometimes you have to get out the volt/ohm meter and start chasing voltage drop. Good luck!
 
Good factory prints are your best friend.
I've got 73 prints and extensive experience on that and a 74 car.
I can tell you there are some differences in the cars.
And not all the stuff matches the prints.
BUT those things can be "by passed" for a simple problem like yours.
People have made the best suggestions for the most likely candidates of your difficulties.
You can figure out why your engine won't turn over or crank without all that extra stuff.
 
General help on diagonosing electrical:
Electricity flows from high potential to low potential whenever a circuit is complete. That is a path back to ground on the battery or alternator.
The car has two sources of power. When a circuit is complete, current will flow from whichever one has the higher potential.
Engine off, the battery is the only source of power.
Engine running, the alternator should be the source of power. If it's output voltage is higher than battery voltage, then alternator supplies power.
That's the basics.

Do a visual and physical check on the main circuit, on the branch that doesn't work consistantly.
Get or make a test lamp, and get a multimeter so you can measure voltage and resistance.
These tools will help find trouble spots when they are not visibly obvious.
Chrysler included an ammeter in their cars and trucks. It indicates current flowing to or from the battery. Pay attention to it and it can be a useful tool.
Keep in mind that 1975 main feeds may be a little more complicated than shown in the schematics shown here. But the concept is the same.
Understanding Charging Systems with Ammeter

Learning to read the factory electrical diagrams is a big help.
Highlight or redraw the circuit you are interested in. That makes it 10 times easier to understand.
Chrysler had series of booklets and films for the service techs. They are a good resource.
Probably the best assemblage is here: Master Technician Service Conference - Chrysler's Training for Mechanics
There's a website called "mymopar" that has some that the Imperial Club does not. They also have some Service Manuals available for download. If you don't have a CD or print copy, this is a good and perhaps your only option until you can get one. A lot of their stuff has been copied without credit or permission so quality of the scans varies.
 
one more thing to try...run an extra ground wire from the block (on a clean bare metal area of course) right the battery ground
 
44070dart said:
Ammeter also a good place to look if equipped with one. Maybe a loose connection, move the wires make sure it is a firm connection. Dangerous place for a bad connection.
Click to expand...

And with moving wires around while investigating disconnect the battery
 
littleduster225 said:
hey guys. im new here, i see around the thread alot of helping going on and was hoping you guys could help me with my first car. i have a 75 duster and its been acting up since i got it. there would be days when it simply wouldnt crank and accessories like radio and lights wouldnt work then they suddenly work again. that was a couple months ago now something similar has happened and it hasnt been fixed for days. ive replaced the starter relay and the fuses, and made sure the battery was good. tested with a new one but still nothing. hope you can help out. Any thing is much appreciated
Click to expand...

Something you may want to try. Go to any parts store and buy some Evapo Rust. Make sure you get a gallon. In the engine compartment take your bulkhead connections loose. Get yourself a plastic container large enough for the connectors to fit in. You’ll have to loosen the cables a bit to allow The connectors to hang down. Fill the container with Evapo Rust. You’ll need something like cardboard to set the container on so it won’t spill. Take your connectors and submerge them in theEvapo Rust. Leave them submerged for 24 hours. After they have soaked take a squirt bottle of heat water and rinse out the connectors. Then blow dry. Good source for that are those cans of compressed air.

Now, you can remove the bulkhead connector from inside the car. Again repeat the procedure. Be care full not to spill any liquid on your carpet.

Once dry you’ll see the pins on the three connectors in the engine compartment clean and free of corrosion. Before putting everything back together take a q tip and dab some dialectic grease on the pins.Remember, disconnectyour battery before working on electrical.
 
You sure it's a 75?
I think 74s or 73s had a seat-bottom switch interlock with a module under the hood that would act up and cause a no-crank. I think it was a 1-year only deal tho.
 
diymirage said:
one more thing to try...run an extra ground wire from the block (on a clean bare metal area of course) right the battery ground
Click to expand...
Easy way to check this as a fix is hook up jumper cable to neg (-) only and clamp other end to bumper. Lights, accessories, horn should all work trying this procedure if the Neg ground was bad.
 
Thank you all for the resposes. i located the firewall connector from under the hood and cleaned them up to the best of my abilities but still nothing. i saw that there was another firewall connector looking thing on top of the pedals. maybe cleaning that up as well? or anyb other ideas on what to check? could it possibly be the ignition switch? but if it were the ignition switch, shouldnt the lights still power on regardless the swutch not working?
 
littleduster225 said:
Thank you all for the resposes. i located the firewall connector from under the hood and cleaned them up to the best of my abilities but still nothing. i saw that there was another firewall connector looking thing on top of the pedals. maybe cleaning that up as well? or anyb other ideas on what to check? could it possibly be the ignition switch? but if it were the ignition switch, shouldnt the lights still power on regardless the swutch not working?
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Yes.
See my response in your other thread.
No cranking, radio, interior lights or headlights working.
1976 Wiring is very different than previous years. 1975 I'm not sure what you have under the hood, or whether its been altered Take and post some photos.
Also might want to look at this thread for an example how meters can be used to pinpoint a problem location. Even with some communication confusion, the location was identified by the testing.
Had headlights, then high beam only, now nothing
 
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I get the same symptoms with corroded battery connectors on my Duster, every year or so I have to clean and reinstall the connectors and lugs on the battery. I think it has something to do with the high altitude and dry air, IDK.

Get one of those battery terminal brushes if you don't already have one and give the terminals and cable connectors a good scrubbing.
 
Mattax said:
Yes.
See my response in your other thread.
No cranking, radio, interior lights or headlights working.
1976 Wiring is very different than previous years. 1975 I'm not sure what you have under the hood, or whether its been altered Take and post some photos.
Also might want to look at this thread for an example how meters can be used to pinpoint a problem location. Even with some communication confusion, the location was identified by the testing.
Had headlights, then high beam only, now nothing
Click to expand...
is it possible for my ignition module connector to be the culprit? had a buddy sit in the car while i wiggled some wires around and i played with the ignition module connector and the lights turned on for a few seconds as well as the radio. also would like to add that i replaced the ballast resistor and the voltage regulator.
 
dart4forte said:
Something you may want to try. Go to any parts store and buy some Evapo Rust. Make sure you get a gallon. In the engine compartment take your bulkhead connections loose. Get yourself a plastic container large enough for the connectors to fit in. You’ll have to loosen the cables a bit to allow The connectors to hang down. Fill the container with Evapo Rust. You’ll need something like cardboard to set the container on so it won’t spill. Take your connectors and submerge them in theEvapo Rust. Leave them submerged for 24 hours. After they have soaked take a squirt bottle of heat water and rinse out the connectors. Then blow dry. Good source for that are those cans of compressed air.

Now, you can remove the bulkhead connector from inside the car. Again repeat the procedure. Be care full not to spill any liquid on your carpet.

Once dry you’ll see the pins on the three connectors in the engine compartment clean and free of corrosion. Before putting everything back together take a q tip and dab some dialectic grease on the pins.Remember, disconnectyour battery before working on electrical.
Click to expand...

is it possible for my ignition module connector to be the culprit? had a buddy sit in the car while i wiggled some wires around and i played with the ignition module connector and the lights turned on for a few seconds as well as the radio. also would like to add that i replaced the ballast resistor and the voltage regulator.
 
littleduster225 said:
is it possible for my ignition module connector to be the culprit? had a buddy sit in the car while i wiggled some wires around and i played with the ignition module connector and the lights turned on for a few seconds as well as the radio. also would like to add that i replaced the ballast resistor and the voltage regulator.
Click to expand...
specs03.jpg
 
littleduster225 said:
is it possible for my ignition module connector to be the culprit? had a buddy sit in the car while i wiggled some wires around and i played with the ignition module connector and the lights turned on for a few seconds as well as the radio. also would like to add that i replaced the ballast resistor and the voltage regulator.
Click to expand...
Tells me you need to take bulkhead connector apart and clean it. There may be melted connectors too.
You need to do a search on bulkhead connector repair, as i cant offer much info on procedure as i am not familiar with your type of connector.
All i can say is it will be brittle so proceed carefully.
 
littleduster225 said:
is it possible for my ignition module connector to be the culprit? had a buddy sit in the car while i wiggled some wires around and i played with the ignition module connector and the lights turned on for a few seconds as well as the radio. also would like to add that i replaced the ballast resistor and the voltage regulator.
Click to expand...
It tells me that your wiring harness is the culprit. A loose connection somewhere. As it’s been suggested before. CHECK EACH CONNECTION AND EVERY CONNECTION.

Start at the headlights and move back wards thru the car. Check it all or you’re going to end up with a toasted Marshmallow in the shape of what was a car
 
Go to mymopar.com and download every single manual for your car for free. Print off the schematic(s) that you will need.
I would disconnect battery 1st, then go thru each connector on bulkhead 1by 1.
Make a list and good luck!
 
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