Step by step guide for idiots ( idiot, me )

-

nodemon

FABO Gold Member
FABO Gold Member
Joined
Mar 21, 2015
Messages
1,397
Reaction score
817
Location
St.Louis
Trying to get things buttoned up on starting engine for first time.. Doing a points to electronic conversion (anothe story)..
Before harness was removed, I had all lights, horn, etc working.. Removed engine bay harness, stripped and painted bay...set engine in.. Installed mini starter (my stock cables are a little short (another story)...
Was trying to follow conversion schematic and wire things up.. Piggy-backed to the ballast resistor, wire to coil and plugged in distributor... SO, I put a test light to the piggyback at ballast with key off, nothing...turned key to "on" and had power at piggyback... Dash lights worked, all seemed good... Battery was low so I put my charger to it...some "sparking" at battery terminal when attaching charger... Gave the key a quick turn to start to see if i had anything...Nothing... then I noticed no dash lights... nothing at ballst piggyback...
What did I f'up now...lol
Not really sure where to start and how to go about it even if i did.. I have a decent multimeter, but haven't much of a clue on how to use it on this situation...
Help..?
 
Test light! Check all your fuses & check the fusible link wire under the hood. should be near the driver's side hood hinge area & it might have a tag made right on it that says "fusible link"
If not, the wire is very flexible so it burns out quick, like a regular fuse. If you don't have a test light, get one, they're good to have.
Make sure you don't have a positive wire touching ground anywhere FIRST!
 
This wasn't a good time to tepair wiring, right before an engine break-in. You need to make sure your engine will fire on first turnover. Don't be one of those guys that grind and grind on their new engine figuring out you don't have any spark. It will end badly! Good luck and let us know how things went.
 
This wasn't a good time to tepair wiring, right before an engine break-in. You need to make sure your engine will fire on first turnover. Don't be one of those guys that grind and grind on their new engine figuring out you don't have any spark. It will end badly! Good luck and let us know how things went.
I agree. Nor would I have done the conversion. I would have started it up on the points. Oh well. Water under the bridge now.
 
Trying to get things buttoned up on starting engine for first time.. Doing a points to electronic conversion (anothe story)..
Before harness was removed, I had all lights, horn, etc working.. Removed engine bay harness, stripped and painted bay...set engine in.. Installed mini starter (my stock cables are a little short (another story)...
Was trying to follow conversion schematic and wire things up.. Piggy-backed to the ballast resistor, wire to coil and plugged in distributor... SO, I put a test light to the piggyback at ballast with key off, nothing...turned key to "on" and had power at piggyback... Dash lights worked, all seemed good... Battery was low so I put my charger to it...some "sparking" at battery terminal when attaching charger... Gave the key a quick turn to start to see if i had anything...Nothing... then I noticed no dash lights... nothing at ballst piggyback...
What did I f'up now...lol
Not really sure where to start and how to go about it even if i did.. I have a decent multimeter, but haven't much of a clue on how to use it on this situation...
Help..?
OK, look, WE can't imagine what you have

1...What year model is the vehicle?

2...I assume ?? from your comments that this is NOT ? a factory like harness, but a more universal harness? yes? no?

3...What is this "piggy backed to ballast?"

4...Post brand/ model and or a clear photo of your meter, we can step you right through some of that.

5...If your points dist. is in good shape it should not be that hard to "convert back." This would be a better path for engine break in. You want to minimize possible problems when breaking in.

IF THIS IS a factory wiring harness, do you have a diagram/ service manual? If not, you can download many years, free, from MyMopar.com. You may have to accept Dodge vs Plymouth, etc. Also in the wiring section there, are aftermarket/ 3rd party diagrams that are not as well detailed or complete (accessories, etc) but CAN be easier to follow. I often use both
 
This wasn't a good time to tepair wiring, right before an engine break-in. You need to make sure your engine will fire on first turnover. Don't be one of those guys that grind and grind on their new engine figuring out you don't have any spark. It will end badly! Good luck and let us know how things went.
Luckily, I guess, there's no power to starter from key...so no worries about grinding the engine, plus, it's not a fresh rebuild. Engine has miles on it but has been sitting for a few years. I did prime pump and had good flow just before electrical issue.
 
I agree. Nor would I have done the conversion. I would have started it up on the points. Oh well. Water under the bridge now.
I didn't have a points distributor. I'm assuming the previous owner was planning on a conversion, or just stuck a distributor in. It was a non running engine in the car. I bought a used 318 and dropped it in, primed pump with good flow to the rockers before this electrical issue. No power from key to starter anyway, so no grinding anything.
 
OK, look, WE can't imagine what you have

1...What year model is the vehicle?

2...I assume ?? from your comments that this is NOT ? a factory like harness, but a more universal harness? yes? no?

3...What is this "piggy backed to ballast?"

4...Post brand/ model and or a clear photo of your meter, we can step you right through some of that.

5...If your points dist. is in good shape it should not be that hard to "convert back." This would be a better path for engine break in. You want to minimize possible problems when breaking in.

IF THIS IS a factory wiring harness, do you have a diagram/ service manual? If not, you can download many years, free, from MyMopar.com. You may have to accept Dodge vs Plymouth, etc. Also in the wiring section there, are aftermarket/ 3rd party diagrams that are not as well detailed or complete (accessories, etc) but CAN be easier to follow. I often use both
72 Demon with 71 318.
Original harness...at least appears to be.
The piggyback is part of the conversion I was attempting, per instructions, and admittedly, I should have left alone.
I have schematics and thought I was doing ok with it..
20241227_105412.jpg
Screenshot_20241227_111108_Photos.jpg
 
Last edited:
I didn't have a points distributor. I'm assuming the previous owner was planning on a conversion, or just stuck a distributor in. It was a non running engine in the car. I bought a used 318 and dropped it in, primed pump with good flow to the rockers before this electrical issue. No power from key to starter anyway, so no grinding anything.
Understood. ....but you ain't no idiot. You're on here askin questions tryin to get it cleared up.
 
I hope it's as simple as that (fusible link)... A way to test JUST that..?

My schematic on my 68 shows the fusible link wire goes from the top post of the starter relay to the "J" terminal in the bulkhead (yours might be a different terminal but the same method applies). Set your multimeter to DC volts, place your black lead on the battery ground terminal and the red lead on the top post of the starter relay. Should see full battery voltage there. Then take the red lead and stick it in the J terminal in the bulkhead and make contact with the metal connector in there. You should see essentially the same voltage at that point. If there's no voltage or a much lower voltage, your fusible link is blown. Ensure you are making good contact with that terminal. You can fool yourself into thinking you don't have voltage if you aren't making good contact.

Also check your fuses under the dash. Set your multimeter to ohms and place the leads across each fuse and ensure that you have continuity across each one.

If anything is blown, you need to figure out why. There's more than likely a short somewhere.
 
When he said there was a spark at the battery, there's a load somewhere? Possible reason for low battery. Fuseable link should be at the bulkhead connector, blue? If blown wire would appear to have a bubble in the insulation or melted.
 
72 Demon with 71 318.
Original harness...at least appears to be.
The piggyback is part of the conversion I was attempting, per instructions, and admittedly, I should have left alone.
I have schematics and thought I was doing ok with it.. View attachment 1716344568View attachment 1716344600
OK, now if you can post the model or photo of your meter, we can give you a few hints, there. Or if you have a test lamp, that may be good enough, meter tho is better.

START VOLTAGE

Bear in mind there is only so much going in/ coming out of the key switch:

main power into the ignition switch, hot all the time, unless fuse link is blown


RUN: In the run position, ACC (accessory) and the "run" or IGN1 line is hot. This branches off, feeds the warning lamps and gauges and comes out through the bulkhead connector, usually dark blue, and feeds (depending on year/ model) the siwtch side of the ballast, the blue wire on the connector for the VR, and the light blue going to one of the two field connections on the alternator. Electric choke if used, and a couple other things if equipped

BYPASS: When the key is twisted to start, BOTH the ACC and "run" lines GO DEAD. The ignition power during starting comes from the IGN2 terminal on the key, often brown, comes out through the bulkhead connector, and terminates at the coil + side of the ballast

START: Meanwhile, a separate contact in the switch also is "hot" during crank, this is often yellow, comes out and connects to one of the small flag "push on" terminals on the start relay. This is the "start" signal, which would turn on the electromagnet (coil) in the start relay HOWEVER the SECOND flag / push on terminal MUST BE grounded. If you have an auto, that second terminal goes down the firewall, over the top of the transmission, and connects to the center terminal of the reverse/ neutral start switch on the Torqueflite. If you have a stick that goes through the firewall (single grommet) and connects to the clutch safety switch. When the start relay energizes, it feeds power and energizes the starter solenoid, cranking the engine

If nothing at all works in ACC or "run" you are likely not getting power through into the interior. DO THE headlights work?

Go out to the engine bay and probe the large black connected to the output stud of the alternator. This should be 12V at all times. If not, you have a blown fuse link, bad connections in the bulkhead connector or other problems

FUSE LINK: This is a special looking wire, with a molded tag attached. it usually goes from the big stud on the start relay ( battery power) to the big red wire going through the bulkhead connector. Probe and test those, should be 12V at all times. If not, go back to the starter relay "big stud." If that is dead, you likely have main battery cable issues
 

My schematic on my 68 shows the fusible link wire goes from the top post of the starter relay to the "J" terminal in the bulkhead (yours might be a different terminal but the same method applies). Set your multimeter to DC volts, place your black lead on the battery ground terminal and the red lead on the top post of the starter relay. Should see full battery voltage there. Then take the red lead and stick it in the J terminal in the bulkhead and make contact with the metal connector in there. You should see essentially the same voltage at that point. If there's no voltage or a much lower voltage, your fusible link is blown. Ensure you are making good contact with that terminal. You can fool yourself into thinking you don't have voltage if you aren't making good contact.

Also check your fuses under the dash. Set your multimeter to ohms and place the leads across each fuse and ensure that you have continuity across each one.

If anything is blown, you need to figure out why. There's more than likely a short somewhere.
11v right now to starter relay and "j" terminal, so I guess fusible link is intact.. Also continuity across all fuses.. I'm thinking I may have fried something on the cluster..?
I just hate to pull it out until I can eliminate everything before...but maybe I need to..?
 
I'm not an electrical person, but we could talk a little, get you calmed down and establish what you do and don't have. We talked about your clutch a couple of weeks ago.
 
I'm not an electrical person, but we could talk a little, get you calmed down and establish what you do and don't have. We talked about your clutch a couple of weeks ago.
Right on..!
OK, now if you can post the model or photo of your meter, we can give you a few hints, there. Or if you have a test lamp, that may be good enough, meter tho is better.

START VOLTAGE

Bear in mind there is only so much going in/ coming out of the key switch:

main power into the ignition switch, hot all the time, unless fuse link is blown


RUN: In the run position, ACC (accessory) and the "run" or IGN1 line is hot. This branches off, feeds the warning lamps and gauges and comes out through the bulkhead connector, usually dark blue, and feeds (depending on year/ model) the siwtch side of the ballast, the blue wire on the connector for the VR, and the light blue going to one of the two field connections on the alternator. Electric choke if used, and a couple other things if equipped

BYPASS: When the key is twisted to start, BOTH the ACC and "run" lines GO DEAD. The ignition power during starting comes from the IGN2 terminal on the key, often brown, comes out through the bulkhead connector, and terminates at the coil + side of the ballast

START: Meanwhile, a separate contact in the switch also is "hot" during crank, this is often yellow, comes out and connects to one of the small flag "push on" terminals on the start relay. This is the "start" signal, which would turn on the electromagnet (coil) in the start relay HOWEVER the SECOND flag / push on terminal MUST BE grounded. If you have an auto, that second terminal goes down the firewall, over the top of the transmission, and connects to the center terminal of the reverse/ neutral start switch on the Torqueflite. If you have a stick that goes through the firewall (single grommet) and connects to the clutch safety switch. When the start relay energizes, it feeds power and energizes the starter solenoid, cranking the engine

If nothing at all works in ACC or "run" you are likely not getting power through into the interior. DO THE headlights work?

Go out to the engine bay and probe the large black connected to the output stud of the alternator. This should be 12V at all times. If not, you have a blown fuse link, bad connections in the bulkhead connector or other problems

FUSE LINK: This is a special looking wire, with a molded tag attached. it usually goes from the big stud on the start relay ( battery power) to the big red wire going through the bulkhead connector. Probe and test those, should be 12V at all times. If not, go back to the starter relay "big stud." If that is dead, you likely have main battery cable issues
20241227_141730.jpg
 
OK, now if you can post the model or photo of your meter, we can give you a few hints, there. Or if you have a test lamp, that may be good enough, meter tho is better.

START VOLTAGE

Bear in mind there is only so much going in/ coming out of the key switch:

main power into the ignition switch, hot all the time, unless fuse link is blown


RUN: In the run position, ACC (accessory) and the "run" or IGN1 line is hot. This branches off, feeds the warning lamps and gauges and comes out through the bulkhead connector, usually dark blue, and feeds (depending on year/ model) the siwtch side of the ballast, the blue wire on the connector for the VR, and the light blue going to one of the two field connections on the alternator. Electric choke if used, and a couple other things if equipped

BYPASS: When the key is twisted to start, BOTH the ACC and "run" lines GO DEAD. The ignition power during starting comes from the IGN2 terminal on the key, often brown, comes out through the bulkhead connector, and terminates at the coil + side of the ballast

START: Meanwhile, a separate contact in the switch also is "hot" during crank, this is often yellow, comes out and connects to one of the small flag "push on" terminals on the start relay. This is the "start" signal, which would turn on the electromagnet (coil) in the start relay HOWEVER the SECOND flag / push on terminal MUST BE grounded. If you have an auto, that second terminal goes down the firewall, over the top of the transmission, and connects to the center terminal of the reverse/ neutral start switch on the Torqueflite. If you have a stick that goes through the firewall (single grommet) and connects to the clutch safety switch. When the start relay energizes, it feeds power and energizes the starter solenoid, cranking the engine

If nothing at all works in ACC or "run" you are likely not getting power through into the interior. DO THE headlights work?

Go out to the engine bay and probe the large black connected to the output stud of the alternator. This should be 12V at all times. If not, you have a blown fuse link, bad connections in the bulkhead connector or other problems

FUSE LINK: This is a special looking wire, with a molded tag attached. it usually goes from the big stud on the start relay ( battery power) to the big red wire going through the bulkhead connector. Probe and test those, should be 12V at all times. If not, go back to the starter relay "big stud." If that is dead, you likely have main battery cable issues
Battery is 10v - 11v right now.. Connection at alternator stud is same.. as well as link at bulkhead. No lights work, interior or exterior... Weird, just out of the blue, my door buzzer went off for about 10 seconds, then stopped...
 
11v right now to starter relay and "j" terminal, so I guess fusible link is intact.. Also continuity across all fuses.. I'm thinking I may have fried something on the cluster..?
I just hate to pull it out until I can eliminate everything before...but maybe I need to..?

11v at the starter relay is low. Is it also 11v at the battery terminal? You'll want to either get it charged up correctly or replace it if it's bad. You could have a parasitic draw that is draining your battery. A bad or poor performing battery could have you chasing your tail on troubleshooting everything else if you don't get that corrected.

To test for parasitic draw, disconnect the negative battery cable from the battery. Clip the test light to the battery cable and then touch the test light probe to the neg battery terminal to complete the circuit. If the light is on, this means something is drawing power. Ensure all switches are off and no lights are on anywhere in the vehicle. If everything is off, remove the fuses one at a time until the test light goes out. That will tell you which circuit to start troubleshooting.

A short somewhere can cause a parasitic draw.

I wouldn't worry about guessing about frying something in the cluster. Use your tools, some simple troubleshooting and the schematics to find out exactly where the issue is. It'll save you a ton of time and you'll get a good grasp on how the electrical system works and how to troubleshoot it. Keep asking questions when you're stumped and we'll get you there.
 
11v at the starter relay is low. Is it also 11v at the battery terminal? You'll want to either get it charged up correctly or replace it if it's bad. You could have a parasitic draw that is draining your battery. A bad or poor performing battery could have you chasing your tail on troubleshooting everything else if you don't get that corrected.

To test for parasitic draw, disconnect the negative battery cable from the battery. Clip the test light to the battery cable and then touch the test light probe to the neg battery terminal to complete the circuit. If the light is on, this means something is drawing power. Ensure all switches are off and no lights are on anywhere in the vehicle. If everything is off, remove the fuses one at a time until the test light goes out. That will tell you which circuit to start troubleshooting.

A short somewhere can cause a parasitic draw.

I wouldn't worry about guessing about frying something in the cluster. Use your tools, some simple troubleshooting and the schematics to find out exactly where the issue is. It'll save you a ton of time and you'll get a good grasp on how the electrical system works and how to troubleshoot it. Keep asking questions when you're stumped and we'll get you there.
Test light lit, but very dim..
Light went out when "dome / cig lghtr" fuse removed.
 
Last edited:
A fully charged battery should measure 12.6v. If you have less than this after charging the bat, then:
- the charger is faulty
- if the bat is still connected, something is drawing a load
- battery is stuffed.
 
-
Back
Top