I recently went thru an ordeal replacing my ignition switch actuator. After finishing the job, the truck started up perfectly. I didn't run it for long.

The next day, I go to start it and there's nothing. No dashboard lights, no interior lights when the door is open, no radio, nothing. The headlights won't even turn on.

It's as if there isn't a battery in the truck. (There is, and I had it tested at AutoZone and it came back good.) There are 12.6+ volts between the top of the starter solenoid and the battery negative.

I'm not sure where to start looking.

As always, your help is appreciated.

 

So the battery shows good so we need to check more why no power to the IGN switch or anywhere else.
At the starter solenoid where the battery cable is you should have 1 or more wires bolted to the same stud.
They would be fuse link wires. They are fuses that take a little longer to blow so they can support a "spike" of power before dropping off to normal.
It sounds like 1 of the links has blowen but can also be a bad connection at the solenoid. Disconnect the battery and clean all the wires and cable at the solenoid first.
There are a few ways to check for a bad fuse link.
Using a test light check for power at the wire just before it goes into the main harness. If no power move up the wire to the solenoid to see if you get power.
If you get power up a little bit the fuse link blew.
Sometimes you can pull on the wire at the harness and if it stretches it most likely is bad.
Sometimes you can make a arc of the fuse link and if it makes a sharp bend it is most likely bad.

The local parts store should have replacements links.
There should be a rubber block where the link joins the normal wire and it should have a amp number on it to get the right size fuse link wire.
Dave ----

 

Thanks, Dave. I'll try giving all the connectors a good cleaning and see if that helps. (I'll be really happy if it's that easy of a fix.) If not, I'll test the fusible links.

 

The fuse links are not all that hard to replace either. Hard part is finding it.
Some come with a butt connectors but if not get some, just strip the insulation off and crimp the connector on and done.
Dave ----

 

Here are the fusible links on my 86 302EFI.

 

I see the start/ignition link is a red one, 18 GA
The red wire on the stud.

 

FML. I replaced the 4 fusible links. (2 16s, an 18, and a 20.) I turned the key and it made 1 click. No radio. (Interior light does come on.) Tried again and nothing. Battery is showing 12.58V. Tried again 10 minutes later and the fasten seatbelts warning buzzer and light came on, 1 click, and then nothing.

 

So we're dealing with a new ignition switch... just because it worked once...

Can you turn the switch to On and jump the solenoid and see if it cranks ?

There are trouble shooting steps to follow, Karl likes to post them.

You say (2) 16ga, I think there should be one. You have a 86' 302EFI like mine, see the photo above of my solenoid with wires.

The 18ga is for the ignition/starter.

Here's where the info/diaphragm comes from, https://www.garysgaragemahal.com/1986-evtm.html
This may not help but,

 

Leave the door open so the interior light stays on. When you turn the key and it makes a click, what does the interior light do? If it goes out, and then comes back on when you let off the key you have a poor connection at the battery, or the battery is dead.

I do not care what voltage you get by just sticking the meter on the battery. If you want to do some testing with the meter in and around the battery area, you must have a helper hold the key to start while you take your readings. Otherwise, your readings are not telling you much. That is what the interior light is being used for, a crude voltmeter. If the interior light stays bright when you turn the key and get the click, then you have other problems.

 

Funny about the dome light, that's something I find myself doing just about every time I start the truck after it has sat for a while. I also always let the fuel pump prime in "On" before cranking the engine over to "start" after the truck has sat.

 

Only 3 fusible links on your truck, Max? There definitely are 4 on mine, and 4 shown in the diagram below. Maybe it was a mid-year change?

I'm now impatiently waiting for the work day to end so I can get out and check on the battery. I'll get my wife to turn the key, and also use the inside light as a voltage indicator.

 

Yep, only three, see 4th pic in post 5. The fourth link is for a "carb" vehicle, as shown in the diagram.

 

If you look at the diagram in post #5, you can see the number of fusible links can vary, depending on how the truck is equipped and the options it has.

 

Max, I think I figured out the difference between our # of fusible links. One of them is for a trailer, and my truck does have a trailer connector in the back. It looks like it came from the factory that way. Does your truck have a trailer connector? Also, you have two additional wires coming off your positive battery post. What are they for? (I'm guessing something like an aftermarket amplifier.)

Anyhow, I tried checking voltage when the key was turned and the multimeter didn't budge. (And the intermittent lights/radio persisted, now with mostly nothing happening.)

I noticed when replacing the ignition lock cylinder there was a copper strip, presumably an electrical connector. I'm wondering what that does. It looks like when the key is switched into the ACC position the ignition actuator doesn't move, so I'm guessing that connection is made separate from the ignition switch. Wondering if the problem lies in that area.

And now that I've stared more at the diagrams, I see there are more fusible links "downstream". It looks like the 37Y goes to the ignition switch. Maybe that's where the problem is. Does anyone know where in the engine compartment that would be?

 

IIRC MAX extra wires at the battery are for electric trailer brake controller, I have the same wires as I also have a trailer brake controller.

As far as I know all fuse links are in the same place at the starter solenoid.
I have had harnesses out of 2 trucks and never seen any others.

I have not had a Ford column apart but if it is like the GM one I rebuilt that copper part was for a key in the IGN buzzer or something like that.
So I dont think that would be the cause of your problem.
Go back ove the battery connections, both sides and if that dose not help I would then go back over the IGN switch / key install.
Dave -----