I popped off the ignition switch connector and it sparked, now will not start

Hello my name is Dave.

While modern cars have fusible links they rely more heavily on mega fuses to protect circuits. On older vehicles like yours they mostly rely fusible links On yours they are at the starter where the main power lead comes in from the battery you'll see some other smaller wires most of which will have a block a short distance from the starter.

If you probe those with a test light I believe you find one that doesn't have power and that will be the one that needs to be replaced. To do this make sure your test light is well grounded and using the sharp probe carefully push it through the insulation of the wire you are testing, I usually turn it a little to be sure I make contact. Do this on the opposite side of the block from the starter.

Please keep us up to date on your progress and thank you for using 2CarPros!

Just in case fusible links are still questionable.

I copied this from another post I answered.

I have a 1977 jeep and a 1946 jeep.

I feel sure you don't have a ford type solenoid like mine, but the fusible links still should be in your system at similar locations.

Anyway, in an attempt to familiarize you with fusible links see my pic at the bottom and what i'm pasting in below.

Pasting:

"ford type" solenoid system, your acces, may vary

1) positive cable from battery

2) out to starter motor

3) on my jeep, this goes to the alternator

4) this feeds my fusebox (all of my accessories)

5) "s" wire is from key, 12v only while you are "cranking"

this wire activates the solenoid's electromagnet, which in turn, connects---a & b internally (only the 2 large gauge cables can handle the amperage the starter "pulls").

When the solenoid is activated, it throws 12v to starter using the large gauge cables (1) pos from batt--thru solenoid internal connection--(2) to the starter, while key is in "cranking" mode.

This is the total reason for a solenoid, because it would not be practical, to run the heavy cables to and from your key switch.

6) "i" wire (optional), feeds coil "full 12v", only while "cranking", after you release the key, the coil reverts back to reduced voltage, supplied by your key in the "run" position.

7) the solenoid's "mount" needs to ground, unit must have a good ground (battery to engine, engine to frame, frame to body [all must connect, somehow] )

(3 & 4, on my jeep) are fusible links, all are not marked, my #3 is, #4 is not. Its sort of a "wire" fuse.

If they are good, tugging on them will be just like a wire, when they are "burned up", they will stretch out like a rubber band.

Should one of these puppies be burned up, it is really important that it be replaced (not bypassed) with the same amp fusible link that was there!

Nothing like taking a shortcut then watching your vehicle burn to the ground!

Keep us (motor master and me) posted on progress!

The medic

Hello again.

No the distributor cap can not cause the engine to not turn over. And the pics that CJMedevac posted does show a good pic of a fusible link (the block with the tag on the left side of the solenoid) of a similar type the your truck should have however like I said yours will be right off the starter since your solenoid is connected directly to the starter. Make sure you are checking for power on the side of the block that leads away from the starter.

If your truck is an automatic there is the possibility that you damaged your neutral safety switch, if memory serves ( our data sources are limited for vehicles as old as yours ) unlike most newer vehicles (later 60's even) yours should be on the steering column under the dash, newer vehicles have it on the transmission where the shifter linkage connects. With your truck I would also pull the ignition switch out of the dash and check to make sure your switch is still sending a signal to the starter, which goes through the neutral safety switch on it's way to the starter.

Using your test light you should be able to see the connectors through the back of the plug on the switch, by touching the connectors you should be able to check for power to each of the wires. Start by checking for power to the switch, again if memory serves it will have to power input wires that will have power at all times. Next turn the switch to run and you should have power to all but one wire coming out of the switch. Then check for power to the last wire while turning the switch to start, you may need help with this as it's difficult to hold the switch, turn it and have the test light securely contacting the wire connector.

Again please keep us up to date on your progress and thank you for using 2CarPros!