Ignition turns but doesn't start the engine

[charmindog]

1973 Bronco and the ignition isn't turning the engine. I am getting power to my gauges. I thought it was a power issue with not enough battery to start the engine, so I have had the batter checked and ensured the terminals and cables are connected appropriately. Thought it might be going too far which can kill the power but that doesn't seem to be an issue. If I end up holding it a bit to the right rather than letting it go then I can eventually get it started. Any suggestions on what the problem might be.

 

[DirtDonk]

Without a little more testing, we don’t know for sure I don’t think.
However, there’s a very good chance that it’s the ignition switch itself, either having worn out, or just being defective.
The bronco looks well restored. Is the ignition switch new?
Obviously it’s getting power to the starter relay and the battery is working fine. You can’t have a battery that is so weak that it won’t fire the ignition, yet still crank the starter.
The starter is the biggest power hog by far on the truck, so if your starter spins quickly and easily like it sounds like yours is doing, the battery is more than fine.
But that doesn’t mean that there is power getting to the ignition when the key goes back to the ON position.
We need some more info too. For example, what type of ignition system is lighting the spark under the hood?
What wiring harness is in there, new or original?
Stuff like that.

Great that you posted some actual video. Definitely helps.
How about some pictures under the hood?

 

[gr8scott]

First off, don't do what you did in the 2nd video. You could end up damaging your starter or flywheel.

Second, what ignition? Stock points?

Seems like you're missing voltage at the coil + terminal with the ignition switch in the run position. Turn the key on and see if there's any voltage at coil +.

As a QUICK test, you could run a jumper wire from BAT+ to coil+ and see if it starts normally. Don't leave the jumper on too long as points don't like full 12 volts for very long.

EDIT: Ha! Paul beat me to it!

 

[Steve83]

You should put ALL your truck's details & history (as much as you know) into your signature(<-click that) so it shows with each post, as this page explains (even though eBs don't have a label like this):

(click this text)


Phone apps don't always show signatures, so you may need to switch to a real browser in desktop mode on your phone, or just use a desktop/laptop computer. Put your location (nearest city) in your profile &/or signature, & upload an avatar of the truck. The more pics you post (NOT in your sig) of the truck, engine, wiring, labels, & undercarriage, the more likely we can help you. Not all its details are relevant to these issues, but you don't necessarily know which ones are relevant, so just put everything in now.

 

[charmindog]

The ignition switch is about 2 years old. First ignition switch only last 6 months so have had some issues with these ignition switches.
I am not positive of the ignition switch brand, its one of the basic/cheaper ones and not the performance brand.
The wiring is all new

 

[DirtDonk]

The fact that it’s new, and that you have already had trouble with one ignition switch, tells me that first and leading suspect would be a second bad ignition switch.
The only other real culprit in the running would be a loose wire, or bad connection somewhere.

Turning the ignition switch to the start position is supposed to cut off all accessory power. So that’s normal.
What’s not normal is that there’s (seemingly) no power getting to the starter relay/solenoid to crank the starter.
That could be a switch, the wiring, and neutral safety switch, if so, equipped, or the starter relay.
A quick test of the starter relay would be to use a jumper wire from the battery to the S post of the relay. If the starter kicks in every time, then it’s not a problem with the starter, or starter wiring.
Of course, you should make sure the vehicle is in park and the brakes on before you try this.

If it works every time then the problem is still upstream somewhere.
Do you have a neutral safety switch on an automatic transmission?

 

[EPB72]

are you still looking for answers?? have you done any diag? Do you own/have a test light and/or multimeter you will need them.. As grtscott said you should test for voltage at positive side of coil ,,, should see power both in run and crank positions, if only during cranking I would remove brown wire at starter relay and recheck for power during cranking.. if theres none in both positions then you need to determine if its a wiring and or ignition switch issue , again you will need a test light/multimeter to pin point ,, new harness you mentioned but who knows how well installed ??? Having a wiring diagram is nice to have do you know wiring harness is installed??? Edit just read Pauls post,, Is this still a crank no start/run issue or is it a nocrank issue???