Won’t Start- Help trouble shooting

[Banjer Picker]

Tried to crank it today and the starter solenoid won’t even click.

Went through the following with zero success:

-Replaced starter solenoid with a new on
-Battery is 100% charged. Also tried to jump it from my truck and jump it with the charger.
-Plannning to replace the ignition switch tomorrow (O’reillys didn’t have any in stock)


How would I start to trouble shoot this one?

What electrical components are between the keyed ignition switch and the starter solenoid?

Any help appreciated.

 

[Calibronc66]

My neutral safety switch has been acting up does the same thing have to mess with the shifter then it fires right up.


Sent from my iPhone using Tapatalk

 

[Slowleak]

What electrical components are between the keyed ignition switch and the starter solenoid?

There is a neutral safety switch in there if you have an automatic.

Have you checked your battery cables? I had the same symptoms once. My negative cable was bad. I was taking it off to clean the connection and the cable pulled right out of the connector where it was bolted to the block.

 

[blubuckaroo]

Try jumpering from the battery to the solenoid coil.

 

[Pa PITT]

... I'd take each ground loose & clean them . Good Maintenance & IT'S FREE. 1ST.
ALSO you might Chock it up . IN park or neural & E-BRAKE ON . HOLD KEY DOWN & wHIP THE STARTER WITH A HAMMER . SEE If it moves the starter.
& Someone can tell you how to jump over the starter.

 

[Banjer Picker]

Mean to add that It’s a manual transmission and a brand new starter too.

 

[B RON CO]

Hi, to test the ignition switch, you need a test light or multimeter, and a helper to turn the key. the starter solenoid has 4 wires, one big one from the battery and one little one next to it, the S terminal. The other side has a big wire going to the starter, and (probably) a little one, on the I terminal.
And the solenoid must be grounded, through the mounting screws.
To test the ignition switch, remove the small wire from the S terminal and hook up the test light to the end of the wire, inside the little plastic elbow. Now have the helper turn the key to start and this wire should become hot, and stay hot when the key is held to start. If this wire does not turn on, trace it back to the ignition switch.
You can also jump the solenoid by crossing the big wire from the battery to the little S post, (with the wire off) and this should spin the starter.
When you jump the solenoid the bronco may start if the key is in the run position, so make sure it is in neutral and be ready.
So first verify if the wire on the little S post is hot when the key is turned to start, and next verify the solenoid is good by jumping it.
Good luck

 

[patterdale]

If you jump the solenoid and it turns over its from the switch to there, if not you probably have a rotten cable. They will rot well up inside the insulation and look normal.

 

[Banjer Picker]

If I connect a test light from the positive battery terminal to the post on the solenoid where the positive battery cable connects should the light come on?

 

[Banjer Picker]

Hi, to test the ignition switch, you need a test light or multimeter, and a helper to turn the key. the starter solenoid has 4 wires, one big one from the battery and one little one next to it, the S terminal. The other side has a big wire going to the starter, and (probably) a little one, on the I terminal.
And the solenoid must be grounded, through the mounting screws.
To test the ignition switch, remove the small wire from the S terminal and hook up the test light to the end of the wire, inside the little plastic elbow. Now have the helper turn the key to start and this wire should become hot, and stay hot when the key is held to start. If this wire does not turn on, trace it back to the ignition switch.
You can also jump the solenoid by crossing the big wire from the battery to the little S post, (with the wire off) and this should spin the starter.
When you jump the solenoid the bronco may start if the key is in the run position, so make sure it is in neutral and be ready.
So first verify if the wire on the little S post is hot when the key is turned to start, and next verify the solenoid is good by jumping it.
Good luck

Thanks for all the info!

When I test the S wire where do I hook the other side of the test light that is not inside the elbow?

 

[B RON CO]

Hi, the alligator clip goes to a good ground, or the negative battery post. Then touch the pointed tip to the positive post, then check the wire. Good luck

 

[Banjer Picker]

So the test light did not light up when connected from the negative terminal to the S elbow. Had he wife turn the key and nothing.

However when I jumped the solenoid it immediately tried to turn over.

Sounds like it’s an isssue between the starter switch and the solenoid. What is the recomendation for dialing it in from there?

I do have a new starter switch coming in tomorrow but it would be great if I could eliminate some potential causes tonight.

 

[B RON CO]

Hi, check to see if the key on things like radio and heater work. Then you will know if the ignition switch is getting power. Google up an ignition switch wiring diagram. Good luck

 

[blubuckaroo]

If I connect a test light from the positive battery terminal to the post on the solenoid where the positive battery cable connects should the light come on?

No. That solenid post should be the same potential as the battery's + post.

 

[DirtDonk]

If I connect a test light from the positive battery terminal to the post on the solenoid where the positive battery cable connects should the light come on?

As said, no.
To test that you need to ground the lead on the test light, then when you put the poker end on the positive side of either the battery or the starter relay, you should get light.
If you don't, then your battery cable is bad, your battery is bad, your ground contact is poor, or the test light is bad.
You can test the test light by hitting both the positive and negative sides of the battery to see if it lights. You can test the ground by trying different grounds, or just going straight to the battery negative (easiest).

Another test is to disconnect the Red w/blue wire on the "S" post of the relay, have a helper turn the key to START and look for the test light to illuminate when touching the conductor inside the Red w/blue wire.
If you do not get a light (and I just read that you did that and it did not light), then as mentioned either your ignition switch is bad, or your NSS circuit is open.

If you have a '73 or later EB with a manual trans, then you still have the NSS circuit. Just without an actual switch. If this is the case (what year is your Bronco?) then a very common issue after all these years is the little loop of wire on the NSS/Backup lamp connector goes bad.

To check this find the 4-wire connector at the top and back of the engine. The chassis side should have two Red w/black wires (backup lamps) and two Red w/blue wires. The engine compartment side will have two Red w/black wires and a loop of Red w/blue.
Separate the two halves and run a jumper wire between the two Red w/blue wires and try the key again. Should start.
Make sure that the S wire at the relay is connected for this obviously.

Good luck.

Paul

 

[Jedeka]

When I got my 74 home, I wanted to see if I could get it running. I put a new starter and starter relay on, but still would not start. I took my jumper cables and connected the black clamps from the battery (-) to the alternator housing. It would now crank over with the key. I replaced the ground cable and cleaned the block, where the cable made contact.

 

[Rustytruck]

As said, no.
To test that you need to ground the lead on the test light, then when you put the poker end on the positive side of either the battery or the starter relay, you should get light.
If you don't, then your battery cable is bad, your battery is bad, your ground contact is poor, or the test light is bad.
You can test the test light by hitting both the positive and negative sides of the battery to see if it lights. You can test the ground by trying different grounds, or just going straight to the battery negative (easiest).

Another test is to disconnect the Red w/blue wire on the "S" post of the relay, have a helper turn the key to START and look for the test light to illuminate when touching the conductor inside the Red w/blue wire.
If you do not get a light (and I just read that you did that and it did not light), then as mentioned either your ignition switch is bad, or your NSS circuit is open.

If you have a '73 or later EB with a manual trans, then you still have the NSS circuit. Just without an actual switch. If this is the case (what year is your Bronco?) then a very common issue after all these years is the little loop of wire on the NSS/Backup lamp connector goes bad.

To check this find the 4-wire connector at the top and back of the engine. The chassis side should have two Red w/black wires (backup lamps) and two Red w/blue wires. The engine compartment side will have two Red w/black wires and a loop of Red w/blue.
Separate the two halves and run a jumper wire between the two Red w/blue wires and try the key again. Should start.
Make sure that the S wire at the relay is connected for this obviously.

Good luck.

Paul

You make damn sure your truck is in neutral, parking brake set and big tire chocks on the tires. You go cranking on the motor with a jumped neutral safety switch and forget to put the truck in neutral the truck is likely to start and run you over especially if you been trying to start it and its full of fuel.

 

[Slowleak]

You make damn sure your truck is in neutral, parking brake set and big tire chocks on the tires. You go cranking on the motor with a jumped neutral safety switch and forget to put the truck in neutral the truck is likely to start and run you over especially if you been trying to start it and its full of fuel.

That’s for sure..... I was troubleshooting my backup lights once. Figured I would jump the wires, on the firewall side of the four wire plug mentioned above, to bypass the backup switch. Well, I accidentally jumped the backup light (red/black) wire over to the neutral safety (red/blue/)wire.

Damn thing fired right up with me under the hood..... I’m lucky that I had not left it in reverse...

 

[Banjer Picker]

Mystery SOLVED!!

Thank you guys!

It turned out to be 4 wire plug that was mentioned and thank goodness Adam Huggins got super specific with it today in a text message.

As it turns out I was trying to clean up my engine bay and pulled out this “crusty brittle old piece of wire harness that doesn’t connect to anything” lol.

The way it was taped it looked like somebody just cut off the ends of the wires and taped them off. I’m guessing hat if I pull the 30 year old electrical tape off it is actually where they created a loop.

I’ve had my bronco for 12 years now and never ran across or even heard of that being “a thing”. Never a dull moment with these broncos!!!


Thank you again for all of the input!!

 

[Banjer Picker]

Next question...

The wires and plug are in REaLLy bad shape. Brittle casing, exposed wires...looks like it could collapse into dust at any second.

Is there a way to make a temporary replacement until I can install my new wire harness after OCBR next month?

My bronco is a ‘73

I’ll search the vendors but do you guys know if anyone of the vendors have this part?

Paul..any chance y’all have one?

The wires are shot and I don’t think I can salvage he plug on the one I have because the wires are bad all the way up to where they go in to the plug.