Blowing Maxi Fuse immediately...?

-

19Dart74

Active Member
Joined
Jul 15, 2023
Messages
40
Reaction score
6
Location
Montana
I am totally green around the ears and strictly trying to wire my 74 Dart with the Painless harness manual and OEM wiring diagrams. I believe that I have done everything to the book. I am jumpy about posting stuff due to trying to not look like an idiot... but here goes. I have wired the entire engine and ignition system less the coolant temp connector, which I'm waiting on a L connector pigtail. The problem is that when I hook up my battery, it immediately blows the Maxi fuse between the starter and ignition relay... I also have my alternator hot wire that painless provides for alternators over 65 amps, connected to the other side of the Maxi fuse. I switched the hot wire from the placement in the photo on the alt. to the blue wire connection which I believe is the positive field side. Maybe I have my alt. wired backwards or maybe I'm totally turned around... Again I'm doing my best with no experience. Any help would be greatly appreciated.

20230726_211247.jpg


20230726_211307.jpg


20230726_211338.jpg


20230726_211350.jpg
 
Do you have a diagram of what the painless harness should result in?

It looks like you have a heavy red cable from the battery to the starter. Then it appears you have a wire from the same positive solenoid stud through the maxi fuse to the relay. This doesn't make sense to me. The red wire from the battery to the relay should end there. Other stuff like the alternator can splice there (versus stacking at the battery terminal), but you effectively have a jumper going right from battery positive to the solenoid. Effectively you're trying to run the starter through that tiny wire, if I'm looking at your pictures correctly.
I'd remove the wire that goes from the relay to the stud on the starter. I would guess the maxi should be a "main" fuse between the battery and the relay hookup, and your alternator goes straight to the battery.
Your photo of the alternator looks correct. The big stud should go to the battery positive, often without a fuse. It wouldn't hurt to out a fuse in though, one about 1.2 times whatever your max alternator output is (65a x 1.2 = 78, Round up to 80). The two field wires should come from the regulator, and either one can be connected to either terminal IF you're using the later style regulator (you should).
Hope this helps.
 
1st No idiots on this site.
2nd you learned a valuable lesson... "Painless" isn't
3rd welcome to the site.

As for the fuse popping. There is a dead short somewhere in that cir. Start at the fuse and work your way away from it till you find the short.

As for the wires on the alternator.

Something is not right.

Where does the black wire go to?

Is the red wire bolted to the alt housing?

Screenshot_20230727-211651.png


This is how it should be wired ( the blue and green might be switched)

Blue would come from a switched 12v supply.

Green would come from the VR.

Large red would go from alt output terminal through maxy fuse to post on starter relay.


Screenshot_20230727-211837.png
 
1st No idiots on this site.
2nd you learned a valuable lesson... "Painless" isn't
3rd welcome to the site.

As for the fuse popping. There is a dead short somewhere in that cir. Start at the fuse and work your way away from it till you find the short.

As for the wires on the alternator.

Something is not right.

Where does the black wire go to?

Is the red wire bolted to the alt housing?

View attachment 1716120225

This is how it should be wired ( the blue and green might be switched)

View attachment 1716120226

I missed the black wire. It does appear it is on the charge stud in Ops photo.
 
When I first looked at the OPs photo I was thinking something is wrong.

The red should be below the field wires.

And the black wire is an unknown unless it is the 12v feed for the horns
 
Last edited:
You're no idiot at all. The idiots at Painless are the idiots. You need a factory wiring diagram so that you can basically install the Painless harness in the same manner, IMO. I've done a few of them on Mopars and that's what made it easier for me. ALL the Painless stuff is GM colored, so that can get kornfrooshing.
 
Thank you for the vote of confidence and welcome to the forum. The black wire is listed as going to the alt output post and leads straight back to the fuse block. As for the red wire it leads straight to the right side of the Maxi that is blowing. I attempted to switch the red in junction with the blue wire which appears to be how one of the diagrams depicts, but another Maxi blew even worse.

20230727_213152.jpg


20230727_213209.jpg


20230727_213243.jpg
 
Thank you for the vote of confidence and welcome to the forum. The black wire is listed as going to the alt output post and leads straight back to the fuse block. As for the red wire it leads straight to the right side of the Maxi that is blowing. I attempted to switch the red in junction with the blue wire which appears to be how one of the diagrams depicts, but another Maxi blew even worse.

View attachment 1716120227

View attachment 1716120228

View attachment 1716120229

Your original photo appears to show the field wires correct.
The red wire should attach at the same point as the black wire. Right now, your red wire has a direct short to the body of the alternator.
The last image in your reply shows a very good overview of how the wiring should work. Your current wiring doesn't quite match, both 915 and 960 should connect at the charging post of the alternator which is where that black wire is shown in your original post.
 
My advice is to break out a test light and check for voltage where it shouldn't be. If you have a multimeter with a continuity tester (the setting that beeps when you touch the probes together) you can disconnect the battery and start removing power wires until you find one that is shorted to ground causing your fuse to fail.

I would be looking very closey at the starter connections, starter relay wiring (is the NSS accidentally hooked to power?), and of course ensure the case of the alternator does not have continuity to the main power post. For safety sake check for voltage with battery hooked up, check continuity with everything unhooked.

Why are there three wires from the starter? There should be one for the solenoid and the main cable to the battery.
 
Last edited:
That make total sense now that you say it. I been staring at OE diagrams and this diagram for over a week straight now and over looked this. Probably not helpful that 915 is both black and blue apparently... this was very helpful. Very grateful for your time.
 
My advice is to break out a test light and check for voltage where it shouldn't be. If you have a multimeter with a continuity tester (the setting that beeps when you touch the probes together) you can disconnect the battery and start removing power wires until you find one that is shorted to ground causing your fuse to fail.

I would be looking very closey at the starter connections, starter relay wiring (is the NSS accidentally hooked to power?), and of course ensure the case of the alternator does not have continuity to the main power post. For safety sake check for voltage with battery hooked up, check continuity with everything unhooked.

Why are there three wires from the starter? There should be one for the solenoid and the main cable to the battery.
I will definitely look closer with a test light and multimeter. The NSS is hooked to the G pin on the relay as depicted in the manual. Ad for the starter the last image is why there is 3 wires to the starter. The battery side has the main battery cable leading to and the 8 gadge wire is leading from to the Maxi. The black wire leads from the solenoid to the center of the relay where the flathead screw is.
 
Do you have a diagram of what the painless harness should result in?

It looks like you have a heavy red cable from the battery to the starter. Then it appears you have a wire from the same positive solenoid stud through the maxi fuse to the relay. This doesn't make sense to me. The red wire from the battery to the relay should end there. Other stuff like the alternator can splice there (versus stacking at the battery terminal), but you effectively have a jumper going right from battery positive to the solenoid. Effectively you're trying to run the starter through that tiny wire, if I'm looking at your pictures correctly.
I'd remove the wire that goes from the relay to the stud on the starter. I would guess the maxi should be a "main" fuse between the battery and the relay hookup, and your alternator goes straight to the battery.
Your photo of the alternator looks correct. The big stud should go to the battery positive, often without a fuse. It wouldn't hurt to out a fuse in though, one about 1.2 times whatever your max alternator output is (65a x 1.2 = 78, Round up to 80). The two field wires should come from the regulator, and either one can be connected to either terminal IF you're using the later style regulator (you should).
Hope this helps.
This is very good insight, thank you. Can you clarify which "big stud" on the alternator that I should route to the battery and which image "looks right" of the alternator. Thank you for your time.
 
This is very good insight, thank you. Can you clarify which "big stud" on the alternator that I should route to the battery and which image "looks right" of the alternator. Thank you for your time.

As @Dana67Dart pointed out, the black wire is currently on "the big stud", which is the insulated stud and is where the charging current from the alternator originates. It, and the two field wires are all that should be connected. Do NOT connect either field terminal or wire directly to power or ground. The top stud, which your red wire is shown attached to in your first photo could be grounded, but it should not be necessary. Just stack your red wire with the black wire on that lower stud the black wire is already on. Make sure none of the ring terminals on that stud are touching anything else either. That would cause a short to ground and still pop the fuse.
 
I believe this would be correct for a "1Wire" alternator. Note in the photo the image of the alt is very different than the image from the one above in your post.

Screenshot_20230728-045646.png
 
This drawing shows wiring close to what was done in '62 -'63.
1690541916590.png


1690542255800.png



That was OK with a slant 6 but runs the battery circuit clsoe to the exhaust.

Wire it like a later vehicle and the battery feed and otehr wires can all be bundled into the inner fender.
1690542995615.png


The fusible link can be replaced with a maxi fuse.
Fuses, circuit breakers, and fusible links need to be sized based on the wires that need to be protected.
The wire to the starter solenoid is only hot when the relay is on, so it doesn't need a fuse.
The heavy wire to the starter carries too much current to protect.

The main wires all connect to the battery positive. So if the fuse is blowing, then something downstream is connecting to ground.
 
Key Off or On, these wires are always hot if the battery is hooked up.
1690543914652.png



Current flow for starting sequence illustrated here

Engine Running, current flow normally looks like this.
1690544274550.png


If the Battery needs charging, then current flow looks like this.
1690544514209.png


A wire with a fuse can be placed to directly connect the battery to the alternator output.
In that case any charging current will take that route as it is shorter.
1690544819865.png
 
If you receive a 90-degree terminal that fits the mopar coolant sender from aftermarket, I/we want to know where you found it. Most Chrysler senders had 3/16 studs on them while most 90-degree insulated terminals found online fit a 5/32 stud ( Ford/Chevy, etc..).
We resort to finding an old mopar in a boneyard and cut the OEM terminal off temp sender or fuel sender, or kast resort, just put a ring terminal on the wire and attach with a toothed washer and hex nut.
Good luck
 
If you receive a 90-degree terminal that fits the mopar coolant sender from aftermarket, I/we want to know where you found it. Most Chrysler senders had 3/16 studs on them while most 90-degree insulated terminals found online fit a 5/32 stud ( Ford/Chevy, etc..).
We resort to finding an old mopar in a boneyard and cut the OEM terminal off temp sender or fuel sender, or kast resort, just put a ring terminal on the wire and attach with a toothed washer and hex nut.
Good luck
Thanks for the heads up! I will let you know if it works.
 
As @Dana67Dart pointed out, the black wire is currently on "the big stud", which is the insulated stud and is where the charging current from the alternator originates. It, and the two field wires are all that should be connected. Do NOT connect either field terminal or wire directly to power or ground. The top stud, which your red wire is shown attached to in your first photo could be grounded, but it should not be necessary. Just stack your red wire with the black wire on that lower stud the black wire is already on. Make sure none of the ring terminals on that stud are touching anything else either. That would cause a short to ground and still pop the fuse.
Thank you for all your help!
 
Key Off or On, these wires are always hot if the battery is hooked up.
View attachment 1716120285


Current flow for starting sequence illustrated here

Engine Running, current flow normally looks like this.
View attachment 1716120286

If the Battery needs charging, then current flow looks like this.
View attachment 1716120294

A wire with a fuse can be placed to directly connect the battery to the alternator output.
In that case any charging current will take that route as it is shorter.
View attachment 1716120295
I was not expecting this much support coming through this forum. Thank you so much!
 
HERE is how you troubleshoot this kind of thing

Get yourself an old headlight that works, or a stop/ tail lamp and socket

Wire the two pigtails of the lamp socket together as this causes a stop/ tail lamp to become one larger lamp

Connect the shell to a ground in the body/ engine, and connect the pigtails to the battery negative post with the normal ground cable disconnected. In other words the lamp is in series from the battery neg post to ground

Now, a short will simply cause the lamp to light, which does two things. As you disconnect various circuits, and the lamp goes out, you know you have found the area of the problem

Second, the lamp protects pretty much the entire harness as not enough current goes through the lamp to cause the short to do any damage

ALSO SUSPECT that the alternator itself may be shorted
 
HERE is how you troubleshoot this kind of thing

Get yourself an old headlight that works, or a stop/ tail lamp and socket

Wire the two pigtails of the lamp socket together as this causes a stop/ tail lamp to become one larger lamp

Connect the shell to a ground in the body/ engine, and connect the pigtails to the battery negative post with the normal ground cable disconnected. In other words the lamp is in series from the battery neg post to ground

Now, a short will simply cause the lamp to light, which does two things. As you disconnect various circuits, and the lamp goes out, you know you have found the area of the problem

Second, the lamp protects pretty much the entire harness as not enough current goes through the lamp to cause the short to do any damage

ALSO SUSPECT that the alternator itself may be shorted
I moved the red wire to the black and solved the fuse blowing issue. One other question if someone has time. With the replacement Painless harness, is the ignition module deleted? The painless Manuel doesn't mention anything about it. Is it better to remove or integrate it?
 
What ignition module. Unless you replace the OEM Mopar module with a different, complete system, you need it. The distributor is nothing but a magnetic trigger.

And what red/ black did you move and where did you move it/ them? If these are the ammeter wires? Which I was not aware painless provided? you just got lucky, and you may have an intermittent problem lurking to return.
 
It's easier to help when we all speak the same language.
Describing the connecting wires by color is generally difficult to decipher.
It looks like Painless has some painful numerical coding on their drawings.

My suggestion is to describe the wire by its connection points, and/or use the Chrysler equivalent.
Chrysler wire name method is pretty straight forward.
On the devices (like switches) the letter convention is slightly different, but if you are using that to describe the wire, just make that clear.
For example on a device B or Batt is a connection that somehow ties back to the Battery positive.
On the starter relay in the above 1963 diagram, St connects to the Starter Switch, and Sol connects to the Solenoid terminal on the starter.

On the wiring diagram, three wires connecting at the starter relay are coded S for Start circuit.
S2 is the wire from the starter switch to the St terminal on the relay
S4 is the wire to the neutral safety switch/clutch switch to insure the car is in N or P to complete the circuit and allow starting.
S5 is the wire connecting the Sol terminal on the relay to the Solenoid terminal on the starter.
1690629018768.png


A = bAttery circuit = any wire connected to the Battery Positive.
R = alteRnator circuits and R6 is almost always power out from Alternator
J1 = Feed to Ignition switch
J2 = Ignition Run (Feeds engine devices and alternator field)
J3 = Ignition Start
H = Horn
L = Lights
Q = Accessories (anything not needed to run the engine. One Accessory feed is always hot, the other is switched on by the key)

Since you are using Painless? wires my suggestion is to use the circuit names rather than the Chrysler coding.
The circuit names and the connection descriptions will help insure your new wires functionally do what they are supposed to do.
 
Last edited:
-
Back
Top