Won't start - Ignition Switch?

[chickenman]

Hi all, I haven't posted in a while but figured here would be the place that I could find the answers I need.

Background on the truck-
'73 with a 302, edelbrock intake carb and cam. I installed a painless wiring harness 6 years ago, an I have had no issues with the truck toll last night. Its been my daily driver for the last 2 months

I drove my '73 last night to work and came out 8 hrs later to a rig that wouldn't start(won't crank). I ubered home and went back today to see what the issue was.

there seems to be no power when I turn to crank. Radio works in the ON position but looses power when I turn it to crank. No blown fuses

I managed to 'jump' start it with a screw driver across the ignition coil posts and get it home. I swapped out the ignition coil and same issue, no crank

My next guess the the ignition switch is toast (original) and I need to just order a new one. It has always been a little sticky in the crank position and I need to make sure the spring returns it the I start the truck.

I pulled the ignition switch out to do a little further inspections and have had nothing but issues with it going back together, or being able to spring back from the crank position.

other than the switch that is now on order, are there any other thougts?

I appreciate the help
Dan

 

[Brush Hog]

I’ve had the same thing happen twice. Once was a broken ground from battery to body. Second time was a bad starter relay. Those are easy to check, test, replace. I’ve actually had multiple starter relays go bad. Don’t buy the cheap ones they don’t last long

 

[Broncobowsher]

Automatic transmission?
Neutral start interlock switch. Typically I will hold the key in start and row through the gears with the shifter. The switch won't just go out of adjustment. Unless the screws holding it on are falling out. If it is out of adjustment, it is probably in adjustment and the bushings on the shifter linkage are going out. Fix the bushings because it may not actually be going into park like you think it is. Even if you think it is, it might only be half into park and getting worse.
I remember someone in highschool had issues with a 60's cougar. Learned how to jump it with the solenoid. Shifter was in park, transmission was in reverse because the bushings went bad. Started it, and it ghost drove into a nursery.

If it is a stick, doesn't apply

 

[chickenman]

C4 auto. I’ve tried starting in Neutral with no luck.

Will be checking the grounds in the AM.

Thanks for all the suggestions

 

[Oldtimer]

I managed to 'jump' start it with a screw driver across the ignition coil posts and get it home. I swapped out the ignition coil and same issue, no crank

?? Do you mean "screwdriver across starter relay posts"?

 

[DirtDonk]

I installed a painless wiring harness 6 years ago, an I have had no issues with the truck toll last night.

Is it the Bronco-specific harness, or a generic setup?

I drove my '73 last night to work and came out 8 hrs later to a rig that wouldn't start(won't crank).

No click or anything?

Radio works in the ON position but looses power when I turn it to crank. No blown fuses

This is the normal action of an ignition switch. All accessory power is killed while the key is in the START position.
Bronco switches even have a nasty habit of killing ignition power if you turn the key too far to the right!

I managed to 'jump' start it with a screw driver across the ignition coil posts and get it home.

As Oldtimer asked, are you sure you don't mean "starter relay/solenoid" instead of the "ignition coil" by any chance?

I swapped out the ignition coil and same issue, no crank

Same question... Did you swap out the ignition coil on top of the engine, or the starter relay on the inner fender/wheel well?

My next guess the the ignition switch is toast (original) and I need to just order a new one.

Probably not a bad idea, but I would NOT throw away the old one just yet. When your new one arrives, keep the old one in reserve in case it's not the issue.

I pulled the ignition switch out to do a little further inspections and have had nothing but issues with it going back together

What kind of issues? Can't get it to click in and lock in place?

If you jumped the starter relay and got it to start, then the starter relay is perfectly fine. It would seem that it's not getting it's signal to start from the key.
This means that it's one of the following issues:
1. Bad ignition switch. We'll find out about that when you install the new one.
2. Bad Neutral Safety Switch. You can test this theory with a volt-meter. Got one handy?
3. Bad wire between the ignition switch and the NSS.
4. Bad wire between the NSS connector and the starter relay's "S" (the one you jumped) post.

A quick test with the volt-meter is to separate the two halves of the NSS connector at the back of the engine. Should be a square 4-wire connector with 2 Red w/blue wires and 2 Black w/red wires.
Pull it apart, note which one is the body side of the connector (you don't need to test the transmission side at the moment), then with someone turning the key to START, check for 12v on both of the Red w/blue wires on the body side connector. Should be power on only one of them, but I can't tell you which one from here. So check both.
If you don't have power, then hopefully the new switch takes care of that.
If you do have power on one of them, then it's time for another test.
With the key OFF and the shifter in PARK and the parking brake ON fully, insert a jumper wire between the two Red w/blue wires in the body side connector.
Turn the key to START again and see if anything happens. If so, then you can be relatively certain that you need a new Neutral-Safety Switch. By now you would already have verified that it's in adjustment and not just hanging there, in which case you would install a new one. You can actually test the switch too, but if you verify that it's adjusted and the starter won't crank in either Park or Neutral, then you need a new one.

Speaking of switches and new harnesses, you may want to verify that any connections/splices that you made when installing the new Painless harness, are still good.

Paul

 

[ared77]

^ Great tips/advice^

 

[Broncobowsher]

The painless harness can make that checking the NSS more difficult.

Just because you tried to start in neutral instead of park does not rule out an NSS issue. As Paul pointed out, that is a great place to check everything. Do you get voltage to the NSS in the start position? Is there continuity between the poles of the NSS in the correct gear selections? etc.

If you don't get a signal at the NSS, then start tracing your way back to the ignition switch. If you do, start tracing your way to the solenoid. You have proven the solenoid works. Won't be a ground issue, you have proven the solenoid has a ground. Everything else is a power circuit.

 

[Steve83]

Background on the truck-
'73 with a 302, edelbrock intake carb and cam. I installed a painless wiring harness...

That and ALL the truck's other details should be in your signature so you don't have to remember to post them each time.

...won't crank).

That's distinct from "won't start", so you should always be as specific as possible about what happens & what doesn't.

...across the ignition coil posts...

I hope that means across the STARTER RELAY posts. This is one place where pics are really useful. Was it like these?

(click this text)

I swapped out the ignition coil...

The coil with the thick wire going to the distributor? Or the starter relay with the thick cables from the battery to the starter?

My next guess the the ignition switch is toast...

Gue$$ing can be really expensive and confusing because it can rapidly lead you down the wrong rabbit hole. Study the wiring diagram & test the switch.

(click this text)

It has always been a little sticky in the crank position...

Have you cleaned & lubed the ignition lock cylinder (where the key goes)?

I pulled the ignition switch out to do a little further inspections and have had nothing but issues with it going back together, or being able to spring back from the crank position.

Post lots of pics.

 

[abrdn419]

I had my starter solenoid go bad last week. Turned the key and nothing would happen not solenoid click or anything. I tested the i terminal on the solenoid and had 12V when someone held the key in start position. I would test that and if you have 12v then your neutral safety, ignition switch is fine.