Simple fuse box fix?

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cudaguy36

cudaguy36

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Hi all, i really hope i get to feel like a fool after someone points out how simple this fix is or were I should look to find the answer since ive been unable to find it so far.
My 1964 Barracuda with a 273 just wont start or show any signs of power to the dash or lights or anywhere. It was running fine yesterday and died right when I pulled into my parking spot luckily. I used a voltmeter to check the power to the firewall , then to the fuse box under the dash and thats where I get lost.
There are no blown fuses but only 2 of the 5 fuses have power to them. And now I noticed a red wire with a small boot on the end (looks like a spark plug boot) comming out of the fuse box and just hanging there (It is "Hot" I checked).
I think it may have popped off of the back of the instrument cluster or something but I dont know where. There is no power to the 2 fuses adjacent to the empty space in the box or the 1 farthest from the empty space in the picture ive included.
Pleeaaase help as I just recently got my motor rebuilt and this is now my daily driver. Sorry in advance for my total lack of electrical knowledge.
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There are NO fuses that prevent the car from running. Since you have only "some power" and I'm guessing?

no headlights? park tail dome?

And it won't crank?

But you DO have power at some point in the fuse panel

THIS IS LIKELY a failed "welded splice" up under the dash in the ammeter black wire from what you said
====================================

Start my making absolutely sure the battery connections are good

Test for voltage.......quick way is with a test lamp for now.

Check at starter relay "the big stud."

From there ALL MAIN POWER feeds in through the bulkhead through the fuse link. So follow that short wire to the bulkhead connector and check it and wiggle it.

Now jump over to the alternator main output stud.........the black nut connection. You have power there?

You can download service manuals and wiring diagrams at MyMopar.com

ALSO READ this article:

Catalog

In that article, pay attention to this simplified diagram, which shows in a nutshell the main power distribution:

amp-ga18.jpg


Follow along the diagram above. I am going from pos to neg which is AGAINST current flow, for "function"

From the battery, power goes to the "big stud" on the starter relay

From there the "fusible link" hooks to a short red wire and goes through the bulkhead connector AND DIRECTLY TO the ammeter (RED)

Through the ammeter, changes to BLACK and goes to the WELDED SPLICE

The splice is up under the dash in that BLACK ammeter wire, you will have to untape part of the harness to inspect it.

FROM THAT SPLICE branches off UNFUSED!!! to feed (depending on year/ model)

Feeds to headlight switch for HEADLIGHT power ONLY (not tail, park or cluster)

Feeds to IGNITION SWITCH

Feeds to fuse panel HOT BUSS

ALSO from that splice the BLACK continues on BACK through the bulkhead connector and ends up at the alternator main output stud

ALSO BE CAREFUL with your tests. You may have "wiggled" a bad connection and lead you down the wrong path

==================================

TO REPEAT........

If you do not have headlights or starter/ ignition/ engine, the problem IS NOT IN the fuse panel. NONE of those devices are fused
 
Last edited:
67Dart273 said:
There are NO fuses that prevent the car from running. Since you have only "some power" and I'm guessing?

no headlights? park tail dome?

And it won't crank?

But you DO have power at some point in the fuse panel

THIS IS LIKELY a failed "welded splice" up under the dash in the ammeter black wire from what you said
====================================

Start my making absolutely sure the battery connections are good

Test for voltage.......quick way is with a test lamp for now.

Check at starter relay "the big stud."

From there ALL MAIN POWER feeds in through the bulkhead through the fuse link. So follow that short wire to the bulkhead connector and check it and wiggle it.

Now jump over to the alternator main output stud.........the black nut connection. You have power there?

You can download service manuals and wiring diagrams at MyMopar.com

ALSO READ this article:

Catalog

In that article, pay attention to this simplified diagram, which shows in a nutshell the main power distribution:

View attachment 1715059279

Follow along the diagram above. I am going from pos to neg which is AGAINST current flow, for "function"

From the battery, power goes to the "big stud" on the starter relay

From there the "fusible link" hooks to a short red wire and goes through the bulkhead connector AND DIRECTLY TO the ammeter (RED)

Through the ammeter, changes to BLACK and goes to the WELDED SPLICE

The splice is up under the dash in that BLACK ammeter wire, you will have to untape part of the harness to inspect it.

FROM THAT SPLICE branches off UNFUSED!!! to feed (depending on year/ model)

Feeds to headlight switch for HEADLIGHT power ONLY (not tail, park or cluster)

Feeds to IGNITION SWITCH

Feeds to fuse panel HOT BUSS

ALSO from that splice the BLACK continues on BACK through the bulkhead connector and ends up at the alternator main output stud

ALSO BE CAREFUL with your tests. You may have "wiggled" a bad connection and lead you down the wrong path
Click to expand...
Thanks so much for the fast response! Thats why I love this forum . I will study this tomorrow morning when I have light (no garage) and try checking those things.Ill post my results as soon as I can.
 
Ok I just home and tried testing some things. Heres what ive got so far, Ive got power to the alternator, power to the starter relay, power to the top and bottom of the fusable link, power to both the black and red wires at the ampmeter . Cant seem to get a light on the firewall block of wires but im havent pulled it off yet since its so stuck and old. Heres a few pics so far.

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Ok also. The firewall bulkhead upper set of wires only has power to the thicker red wire and the thinner black one. No other connectors light up.
It seems like its just got power to alot of places but everything still seems dead.
Im still studying it and trying to figure it out so please bear with me . I dont want it to just sit because I spent all my money on the engine rebuild and cant swing $200 this month for a tow and an hour of shop diagnostic time. Again thanks for any advice and I really appreciate the help so far.

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1498088284490-820377152.jpg
 
If the red at the ignition switch has power you should have headlights, double check?

Also with your light on the ignition red, reach up under and wiggle a few things, the harness, and see if it comes / goes

You can't really test much with the connector apart like that, as that feeds the battery INTO the interior, and then back out through the ammeter circuit to the alternator................That is, leave the connector connected and probe one side of it Also, INSPECT the mating connector at the bulkhead for damage

(Has the wiring been modified?)

At this point I would retest, and see what you "don't have...........that is,.........making CERTAIN the red at the ignition is "hot" see if the ignition switch activates anything at all......

any accessory? wipers/ radio/ heater?
Does it crank?

Does that red go DEAD if you try to activate anything at the key?
 
67Dart273 said:
If the red at the ignition switch has power you should have headlights, double check?

Also with your light on the ignition red, reach up under and wiggle a few things, the harness, and see if it comes / goes

You can't really test much with the connector apart like that, as that feeds the battery INTO the interior, and then back out through the ammeter circuit to the alternator................That is, leave the connector connected and probe one side of it Also, INSPECT the mating connector at the bulkhead for damage

(Has the wiring been modified?)

At this point I would retest, and see what you "don't have...........that is,.........making CERTAIN the red at the ignition is "hot" see if the ignition switch activates anything at all......

any accessory? wipers/ radio/ heater?
Does it crank?

Does that red go DEAD if you try to activate anything at the key?
Click to expand...
Thanks a ton 67dart273. I am all done testing things for today as im exhausted and need sleep. I will try the things you just suggested after work tomorrow and maybe ill have a good update. I feel like the more I understand this cars wiring the closer im getting to a solution, I can just about taste success at the tip of my fingers now Lol.
Thanks alot for being patient and all the great advice.
 
OK, some suggestions. Refer to the MAD diagram

Pick something that does not work and concentrate on that. For example, let's say you have no headlights. Check for power at the proper terminal of the headlight switch, I think that is B1. Refer to the "real" diagram, either from MyMopar or the shop service manual.

If you HAVE that, obviously good thing. IF not, trace back to find out why. That power comes "in order"

Light switch..........welded harness splice......BLACK at ammeter.......through ammeter and back out on RED ammeter wire..........out through bulkhead connector.........and through fuse link........to starter relay stud

If all that checks, then attack the ignition switch

Does the big red have power? If yes, work the key "accessory" and see what you can get to work. If nothing, RECHECK the red for power, and wiggle the thing. Could be "a load" is opening up a bad connection, or switch itself might be bad, etc.
 
One thing to keep in mind... lets imagine every copper stand in a battery cable was broken except 1. Your test lamp would show power yet there wouldn't be enough current to operate anything. Since you said engine replaced recently, double check all positive and ground connections from battery onward, especially if you have those add on cable terminals at the battery. Just a loose bolt where ground cable attaches to block can cause the symptom you have. Good luck with it.
 
You can also check for "spread" female terminals. As stated above, crusty green ugly copper wires may show continuity, while troubleshooting, but will not carry the current load when asked to.
 
DartGTDan said:
You can also check for "spread" female terminals. As stated above, crusty green ugly copper wires may show continuity, while troubleshooting, but will not carry the current load when asked to.
Click to expand...
Ok so I just got home and did the first check. When I put the tester light on the ignition red wire it lights up but when I pull out the headlight knob to on, the light goes out.
So power to the ignition until I try to turn on the headlights. Also no headlights with ignotion on or off. I havent checked the headlight switch yet but will in about an hour.
 
cudaguy36 said:
Ok so I just got home and did the first check. When I put the tester light on the ignition red wire it lights up but when I pull out the headlight knob to on, the light goes out.
So power to the ignition until I try to turn on the headlights. Also no headlights with ignotion on or off. I havent checked the headlight switch yet but will in about an hour.
Click to expand...
Also the red wire on my ignition has power but if I turn the key at all it goes out.
 
YOU ARE MAKING PRGRESS!!!

There is VERY LITTLE between that common point and the battery, now find out where you "lose" the problem

1....Move to the ammeter and put your light one each post, again turning on the key or the lights

2....Both ammeter post tests goes out?.......Check the bulkhead connector where the big RED goes through, and the fuse link OR it's the red wire wire end right at the ammeter

3....NEITHER ammeter post loses power? It's in the welded splice I mentioned earlier

4....ONLY ONE ammeter post loses/ goes out? Then it's right there, either a bad wire end on one of the ammeter wires, or inside the ammeter
 
Progress finally!
I finally got most of the tape off the welded splice so I can start following and inspecting the red and black wires (mostly the black one) and I I lost light and had to stop.
However I decided to poke around under the hood for the last ten minutes I had available and this time I was able to confirm that I had power at the thick red and black wires on both sides of the firewall connector.
Oddly enough this time I discovered I was getting power everywhere, with the wire clamp connected to the negative battery ground bolt on the engine everything I touched the light to had power like a bad ground? Different then what I saw yesterday.
Then I disconnected both wires from my alternator and yeah!!! Dash lights again. Momentary over excitement caused me to be dumb and try to crank it but as soon as I turned the key I saw a small spark at the positive battery terminal (loosely clamped) and nothing again : (
I think I blew my fusable link . The starter relay has power to the big bolt but not the small one that has a black wire poorly attached to a yellow one in the picture.
Im getting sooo close I cant stand having to stop to sleep Lol. Thanks again sooo much to everyone for the help and patience you guys rock! Any tips on where to look for the bad ground? Once I get power again.

20170622_204154.jpg
 
Whatever that is on the starter relay is not correct. The two "push on" blade terminals should have that yellow on one, and the other wire goes down the firewall, over the top of the transmission bell, and down to the newtral safety switch. That last wire grounds the starter relay when the trans is in park or neutral
 
I trouble shot a 1968 Hemi Roadrunner once that had similar problems. Everything was brand new. Battery fully juiced. Dome lights came on when the door was opened but when you tried to start it, everything died. I tracked it down to a new positive battery cable that had a factory defect. The crimped lug on the end to the solenoid wasn't crimped enough to carry the starting current. Replaced it with another new cable and the problem was permanently solved.

But don't just start replacing things to see if your problem is similar. Follow the advice you are being given in this thread to track down your specific problem. These guys know what they're doing! Plus, you will be proud that you fixed it yourself (with advice) and you will have learned valuable skills in the process!
 
68gtxman said:
............... I tracked it down to a new positive battery cable that had a factory defect. The crimped lug on the end to the solenoid wasn't crimped enough to carry the starting current.
Click to expand...

THIS IS a very good point. I got my brain entrenched in what the OP listed as results, and it just might be........

Try probing the "big stud" on the starter relay and see if that also goes dead, when headlights or key is activated............
 
Ok heres an update. Im really getting close now. Yesterday I lulled my battery out and charged it fully for the day while I was at work, then I put the wiring on my starter relay the way 67Dart273 said with the yellow wire on the tab where it belongs.I then swapped out my Voltage regulator with a new one from O'Reillys .Next I removed the negative battery ground connection to the engine and then retightened it back down after making sure its surface was bare metel. I connected back up the battery and pulled out my headlight knob and got headlights and dashlights and everything inside works even my radio ha ha. While the headlights were still on I checked the big bolt on the starter relay and it had power at the big bolt only but no other spots on it. Lastly I turned my ignition key to start and got nothing at all , but im super stoked that every thing didnt die this time.
I left the alternator disconnected still and then disconnected the battery again and called it a night. Im thinking about buying a new starter relay and positive battery cable but wont have any time this weekend unfortunately. Thats all for now and thanks again you all im really loving all the great advice and learning the ins and out of the old girl.

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Before you buy a starter relay check it out.

The brown wire is supposed to ground that relay terminal in park or neutral

The yellow is 12V from the key in the start position. Those two are the magnet/ coil of the relay

So "rig" a test lamp to the yellow, twist the key to start. You should have voltagle

"rig" the light to the brown connection. Do this with all wiring connected normal. If you get a light, the neutral safety switch is NOT GROUNDING

Hold the key to "start" and move the shifter from park to neutral and back. If it tries to engage or clicks, you are "in the area." Either the switch is bad, or the linkage is out of adjustment

You can also remove the brown wire, hook an alligator lead to that relay terminal, and ground it. Using the key, it should crank, be SURE it is not in gear

If the yellow is getting voltage (crank) but the relay won't engage, time to replace the relay
 
67Dart273 said:
Before you buy a starter relay check it out.

The brown wire is supposed to ground that relay terminal in park or neutral

The yellow is 12V from the key in the start position. Those two are the magnet/ coil of the relay

So "rig" a test lamp to the yellow, twist the key to start. You should have voltagle

"rig" the light to the brown connection. Do this with all wiring connected normal. If you get a light, the neutral safety switch is NOT GROUNDING

Hold the key to "start" and move the shifter from park to neutral and back. If it tries to engage or clicks, you are "in the area." Either the switch is bad, or the linkage is out of adjustment

You can also remove the brown wire, hook an alligator lead to that relay terminal, and ground it. Using the key, it should crank, be SURE it is not in gear

If the yellow is getting voltage (crank) but the relay won't engage, time to replace the relay
Click to expand...
67Dart273 said:
Before you buy a starter relay check it out.

The brown wire is supposed to ground that relay terminal in park or neutral

The yellow is 12V from the key in the start position. Those two are the magnet/ coil of the relay

So "rig" a test lamp to the yellow, twist the key to start. You should have voltagle

"rig" the light to the brown connection. Do this with all wiring connected normal. If you get a light, the neutral safety switch is NOT GROUNDING

Hold the key to "start" and move the shifter from park to neutral and back. If it tries to engage or clicks, you are "in the area." Either the switch is bad, or the linkage is out of adjustment

You can also remove the brown wire, hook an alligator lead to that relay terminal, and ground it. Using the key, it should crank, be SURE it is not in gear

If the yellow is getting voltage (crank) but the relay won't engage, time to replace the relay
Click to expand...
Thanks alot , thats super helpful! I was just looking at my wiring diagram trying to figure out what you just explained to me.
Im away from my car right now but am itching to try that out. Ill post another update as soon as I give it a try.
 
Success! 67Dart273 nailed it.
It was the brown wire on the starter relay not grounded. I tried the yellow wire with the key turned to start and it got power, I then held the key to start and went from park to neutral and back and it tried to start for a split second only then nothing.
So I used a jumper to connect the brown wire terminal on the relay to ground and then tried the key and it fired right up!
So it WAS the other end of the brown wire or switch for the neutral park ground.
I cant thank you all enough for all your help and patience. I have learned tons about the wiring in this car and now Im determined to tackle some of the weak spots that are corroded pretty bad like the firewall connectors and I plan to change out (one at a time) all the main circuit wires .
Im sooooo stoked and glad I stuck it out , I definitely wouldn't have been able to solve this problem nearly as fast or inexpensively without the help of all you knowledgeable Mopar guys on FABO.
Again you guys all rock!
 
Now I just need to find the time to fix the switch or linkage for that ground.
But now I can at least drive my car again until then.
 
Great!!! Possibilities you have with the NSS

Bad NSS

Linkage out of adjustment

Bad connector on the wire end (either end LOL)

In rare cases, the "rooster comb" inside the trans comes loose from the shift shaft
 
While swapping engine/transmission, the NSS on my '66 fell out of adjustment at the floor shifter. Not fun to diagnose, but an easy adjustment took care of it.
 
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