Car won't crank, Fusible link blown

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I drove my 318 powered 68 Valiant to work today, and when I got in it to go home, it wouldn't crank at all. No starter, no gauges, nothing. I've had the car do this to me before, but I had gauges and lights, I fixed it then by wiggling wires around on the starter relay. Today I didn't have gauges and lights, I tried wiggling wires around and such, but no luck. My dad came by with some basic electrical tools, we put a multimeter on different wires and found that the fusible link was bad. We went to a parts store and picked up more fusible link, and spliced it over the other link, cutting out almost all of the used link, stripping back the ends and using as little of the old link as possible (we were hoping this would work, because we didn't know how to disconnect the terminals, we were limited on time and tools). When we reattached the battery, everything was good, until I turned the key and the link smoked out and failed. Did the spliced link cause the fail, if so how do we make the connections the right way, or was it something else? Any ideas on how to tackle this are welcome, the car is 20 miles from home and we don't want to tow it home unless we have to.
 
Something important is shorted. If you must drive the car home here's what I'd do.......

Do NOT fix the link. Do this in daytime so you don't need headlights

Get some wire, clip leads, terminals, "stuff."

Disconnect the coil + wire and safe it off with tape

Disconnect the ballast (wait assuming you have points ignition?)

Hook one end of the ballast to coil + terminal and hook the other end to battery. The start relay "big stud" is a good place. Leave the key "off" and crank it up by jumpering the starter relay.

This should give you minimal "running" without danger of smoking something further

If you have electronic ignition, post what it is, might be able to hot wire that
 
If you are sure that turning the key on is what caused "the smoke" then it is something which the key supplies and which is NOT fused. This includes the "run" wire feeding under the hood to ignition and the regulator
 
67Dart273 said:
If you are sure that turning the key on is what caused "the smoke" then it is something which the key supplies and which is NOT fused. This includes the "run" wire feeding under the hood to ignition and the regulator
Click to expand...
We saw 12 volts at the bulkhead connector with the connector disconnected, plugged in the connector, turned the key all the way to start, and then off once the link burned out.
I've got cheapo GM style ready to run HEI distributor on it
 
So for the one wire distributor, just connect the positive wire directly to the battery and then start it by shorting the starter?
 
Yes!!

Don't forget, tho, that there could be a short right there in the ready-to-run set up

When you get to troubleshoot it, do this:

Scare up a tail lamp or backup lamp and socket, or a headlight. Wire that in series with the battery ground. This will allow you to do some testing while the lamp acts as a limiter

Since you think activating the key brought on "the smoke" I would check out the ignition "run" circuit. This would include all the wiring under the hood served by the dark blue "run" circuit

It might also be something in the cluster. Look for blown fuses you missed which would be a clue. If this is an UNFUSED problem, this includes the ammeter and wiring, headlights (only) circuit, and the "hot" buss in the fuse panel. None of those are switched by the key, but all are unfused. Also a shorted alternator

To check the key switched accessory buss, pull all the fuses (one at a time) and see if the short disappears.

Have you added anything to the "run" circuit that could have shorted/ failed? Stereo amp? Radio? Tach?

I would take a good look at the harness going to the alternator, regulator, and ignition system wiring.
 
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As usual, the MAD article might be a help, as they show a simplified diagram for most of the UNfused wiring:

Catalog

amp-ga18.jpg


Follow along. This is against current flow, but explained functionally. From the battery, power goes to the starter relay "big stud." From there the FUSE LINK goes through the BULKHEAD (RED) to the AMMETER. From the AMMETER (BLACK) power goes to the WELDED SPLICE, and back out the bulkhead to the ALTERNATOR

From the WELDED SPLICE power branches off several places depending on model/ year. Branches go to the HEADLIGHT SWITCH, the FUSE PANEL HOT BUSS, power to the IGNITION SWITCH

Notice that NONE of this above is fused or protected in any way except the fuse link!!!!

So far as "switched power" once primary power gets to the ignition switch, it feeds.....

IGNITION RUN circuits, that is powered with key in "run" position

This includes power to the cluster, which feeds gauges, oil and brake warning lamps, and out through the bulkhead to the voltage regulator and ignition system

and ACCESSORY. This power goes direct from IGNITION SWITCH to the SWITCHED BUSS in the FUSE PANEL. That much is ALSO not fused except for fuse link
 
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The hotwire trick didn't work because the starter solenoid would engage, but no starter. Bought the mini starter at napa, hoping it solves the problem
 
Nothing should have changed "down there." The fuse link should not have fiddled with that. You may have some interesting problem
 
67Dart273 said:
Nothing should have changed "down there." The fuse link should not have fiddled with that. You may have some interesting problem
Click to expand...
Something is wrong somewhere. The car runs with jumper cables attached, but wont without. The alt tested as ok, so somewhere something isnt working right.
 
The alternator should not be in the circuit when jumpered as we talked. If the battery won't run it the battery is dead or defective. With a decent battery and no lights (daytime) you should be able to run that car for many many miles "off the battery." The ignition system, by itself, probably draws less than 5A

"Back in the 70's" my RR developed an overcharging problem. We were going back to Miramar (San Diego) from Vegas. I pulled the VR connector loose, and we drove that thing hundreds of miles on the battery with no charging system.

Yeh......that's right!! I'm old!!
 
I have an electric fan on the battery, hardwired through a relay and in-cabin switch. Is it possible that that is what is causing the problem?
 
Of course it could. If you need that fan to get home, you better have at least one extra battery
 
The fan doesnt go thru the fusible link, and we disconnected it with no difference, so thats not it. Got the car home on one battery, minimal fan usage and a truck battery saved it. Now to track down the short
 
When my fusible.link died in my 67 cuda with MP electronic ignition, Del/67Dart273 diagnosed it as a bad alternator. Took 5 minutes of talking on the phone with Del. Lol
Local auto store had it in stock. Problem diagnosed and repaired in under an hour.
Thanks again Del!
 
4spdragtop said:
When my fusible.link died in my 67 cuda with MP electronic ignition, Del/67Dart273 diagnosed it as a bad alternator. Took 5 minutes of talking on the phone with Del. Lol
Local auto store had it in stock. Problem diagnosed and repaired in under an hour.
Thanks again Del!
Click to expand...
Alt checked out. Passed the test 3 times.
 
68Valiant225 said:
The fan doesnt go thru the fusible link, and we disconnected it with no difference, so thats not it. Got the car home on one battery, minimal fan usage and a truck battery saved it. Now to track down the short
Click to expand...


EXCELLENT!!!
 
Re-read post 6. Start by making CERTAIN all loads are off, including lighter, dome light, etc etc. If you have a big stereo unhook that as some of the "final" transistors are hooked up all the time

Wire in a light as I told you and start looking. If you cannot find it, start to isolate stuff........example, notice which bulkhead terminal the "big red" fuse link and the "big black" to the alternator hooks to. Unhook the engine side. With your ground lamp hooked up jumper power to the red and the black on both harness "halves" with the bulkhead connector separated. Neither should light One probably will THAT is the clue

You have diagrams/ shop manual? Download them free, MyMopar.com
 
I've got the manual, I'll probably get going on tracking it down tomorrow, just putting together a game plan now .
Looking at the fusible link, it needs to be replaced, and I can get the packard 56 connectors, but I'm not sure about that end away from the bulkhead. Does that need to be on the factory style connector, or can I just put new terminals on the wires and heat shrink it? Just unsure of if heatshrink will change the characteristics of the link.
 
That connector at the fusible link is basically a service disconnect ( disables everything inside the cab ), So sure you could patch to if there enough wire left there, install a alternative male/female connector of similar rating, or just delete it with solder and heat shrink.
My plan of attack would begin with download the factory service manual, then remove instrument panel. Everything about under dash wiring would be much easier seen/diagnosed/serviced.
 
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