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No Crank, No start

400iso

New Member
Joined
Jul 19, 2018
Messages
30
Loc.
Inglewood
Hi Guys,

My father and I just finished installing our rebuilt 302 in the 73 Bronco this weekend.
However, we don't have crank or start from the ignition switch. Wondering what else it could be as we've installed all of the following items new..

- Rebuilt Engine
- New Voltage Regulator and condenser
- New Alternator
- New Solenoid
- New Battery
- New Starter
- New Ignition Switch

The Bronco fires up from the solenoid right away, but nothing from the key. Fuses all look good.. Could it be a wiring issue? Also, our bronco doesnt seem to have an ICM. Any help or direction would be appreciated!

Thanks
 

77RHINO

Full Member
Joined
Feb 22, 2011
Messages
308
Did you disconnect the square NSS plug running from the firewall behind drivers valve cover down to the transmission?
 
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400iso

New Member
Joined
Jul 19, 2018
Messages
30
Loc.
Inglewood
Thanks for your reply! Yes - we definitely reconnected the cable at the transmission. Would you recommend replacing switch? I'm lost!
 

Hotrodjohn

Full Member
Joined
Feb 12, 2016
Messages
264
try bypassing the neutral safety switch from the C4 and see if thats the problem. Mine failed and did that and was actually shorting out pegging the amp meter in the negative. You will see 4 wires on it, two complete the circuit to the starter solenoid, and two complete circuit to the reverse lights. Just pull the plug on, and engine side and put a jumper wire on there and see if that fixes it. (however if you do this MAKE SURE your in park as it will start in any gear so beware). Im not sure which color wires are which on a 73, maybe someone can chime in on that but I think its the red with blue wires.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
with the key on do you have any voltage at the coil?

with the key turned to start do you have any voltage at the small wire I terminal at the starter solenoid?
 

Boss Hugg

Contributor
Bronco Guru
Joined
Jun 8, 2010
Messages
2,140
Thanks for your reply! Yes - we definitely reconnected the cable at the transmission. Would you recommend replacing switch? I'm lost!

Make sure the shift lever on the transmission is fully engaged in park... Sometimes the adjustment on the column shift lever will get off a bit and the transmission can actually be in reverse when you think it's in park.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
You can always put the truck in neutral with the parking brake on to start too.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,275
...My father and I just finished installing our rebuilt 302 in the 73 Bronco this weekend.

Congrats on getting it installed.
The question I always ask on rebuilt engines is, are you using a flat-tappet cam, or roller cam? And if flat-tappet, have you already broken it in?
I ask because of the difficulty in getting it started, and you didn't mention cam break-in or keeping it running for awhile.

I scrambled some of your items around a bit to work with my comments.

However, we don't have crank or start from the ignition switch.
The Bronco fires up from the solenoid right away, but nothing from the key.

That says that your starter relay/solenoid is not getting a signal from the Red w/blue wire. Could be the key, could be the neutral safety switch, could be the wiring in-between.

Wondering what else it could be as we've installed all of the following items new..
- New Voltage Regulator and condenser
- New Alternator

Those are ok to ignore for the moment, since they have no effect on starting.

- New Battery
- New Starter

Also ok to ignore for now too since the engine started when you jumped the relay. Proves the battery and starter (and starter cable) are good.

- New Ignition Switch
- New Solenoid

Now these could still be at fault. You need to do some testing.
Disconnect the small Red w/blue wire from the "S" post on the starter relay and have someone turn the key to START. You should be able to measure 12v at the wire with the key in the START position.
Likely this is the issue, as you've already tested the relay with your jumper.
If you don't already have a multi-meter (volt-meter, volt-ohm meter) for testing electrical circuits, you should. Bronco owners should have one at all times it seems!

The reason you can't rule out "new" parts anymore is that they often fail quickly, or are faulty right out of the box. And the ubiquitous Ford Starter Relay is probably the most often failed new part there is.
The fact that you already tested yours by jumpering it with a wire to the S terminal (that's how you did it, correct?) you've proven that the relay itself is still good. So my money is on no power at the Red w/blue wire.

So check for power on that wire at the starter relay, then check for power on that same wire up at the ignition switch.
If no power is found in START at the switch, the switch is at fault. If you do find power up there, but not at the relay, then likely something with the neutral safety switch or it's wiring is at fault.

Fuses all look good..

That's always a good thing to check, but there are no fuses in the way of this problem. No fuse controls the starter circuit.

Could it be a wiring issue?

Definitely. Follow the Red w/blue wire as your main suspect.

Also, our bronco doesnt seem to have an ICM.

Correct. They only started using the Dura Spark ignition system in '74 on some Broncos, then '75 on all the rest if I remember.
If you have not already, you can pull the distributor cap off and look for points and condenser, or an electronic trigger. If original, yours has points.
They seem to be working too, as you said the motor runs when you jump the relay/solenoid/thingy. Otherwise, the ignition has no effect on the starter cranking.

Good luck.

Paul
 
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400iso

New Member
Joined
Jul 19, 2018
Messages
30
Loc.
Inglewood
Thanks for the detailed response Paul! My plan is to test the solenoid today to make sure we have power and also test the red and blue cable at both ends. I have a new NSS switch I plan on installing to eliminate as many variables as possible.

The bronco fired up beautifully when we jumped it. We let it run for a while to check other components. Thanks for the tips, going to go at it again tonight after work.
 

DirtDonk

Contributor
Bronco Guru
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Nov 3, 2003
Messages
47,275
Before you replace an old NSS with a new one, make sure it's the problem first.
The reason is, if it's a really old one it's likely a better quality unit too!
Sure, they get old and can fail. Then you have no choice but to replace it. But the new stuff is such junk (sorry, had to call it like I see it) that keeping an older original one is very desirable.
The secondary related reason is that any new part is suspect. Sad but true, that just replacing a part makes you think you have eliminated that as a suspect, when in fact you have simply added another double-secret probation suspect to the mix!

The good new is that it's not always the case. But the bad news is that it's happening way more often these days than it should.
Ford starter relays and neutral safety switches are actually prime players in this game. With the nod going to the starter relays, which fail on such a regular basis that many of us recommend going to the junkyard to find a good factory installed one before buying one from the local discount store.

The jury is still out on the expensive ones however, as not many have forked over the $50, $60 and even up to $80 bucks for one of the supposedly good ones. Not easy to do when a standard one with a lifetime warranty still costs just 20 bucks. But the aggravation of changing them out every two weeks kind of trumps the savings at the pump. So to speak...

Sorry for the rant. Just wanted to catch you before you just threw a new part at it without testing.
Like I said, if yours is bad, 'ya gotta do it. But if it tests good, don't throw away the old one just yet.

Good luck.

Paul
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,275
Oops. Didn't read back and what was already written first, or I'd have seen we touched on the whole "new parts suck" syndrome already.
Oh well, never hurts to emphasize.;)

Paul
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
make sure the small wires at the solenoid are not crossed it won't turn over if they are. since it started and ran being jumped
 
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400iso

New Member
Joined
Jul 19, 2018
Messages
30
Loc.
Inglewood
Thank you guys for all the amazing tips and advice on this. Your expertise helped me not only check but I also learned a bit in the process. Thank you for all of your help with this. After eliminating every possible variable one by one, It came down to the red and blue wire from the starter switch which looked cut and patched up. All of the cables were previously taped together and was able to take the tape off and find the problem. Starts up like a charm.
 
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