Key turn...Nothing. Solenoid jump works

[bronco italiano]

So I have replaced the starter solenoid. Noted that the ignition switch had literally fallen apart. Changed that. Still nothing when key turned (not even solenoid click).
-Coil has 12v with key on.
-Solenoid "I" has nothing when key turned "on" and to "start"

-Centech wiring harness
-Mean Green starter with wiring per RAAAAAYY
-No burnt fuses

-Could the ignition key cylinder be bad?
Thanks,
BI

 

[Broncobowsher]

Automatic transmission? Neutral safety switch? First check is the shifter aligned, bushings in good shape? I've seen bushings go bad and a solenoid jump turn into a runaway car. Poor mercury.

Stick shift, the ignition switch is where I would start. Automatic, that is where I would be down low on the list after the neutral safety switch. Test lights are nice.

 

[bronco italiano]

Manual Trans (Sorry, forgot that important detail)

 

[Broncobowsher]

I would start for a start signal at the switch at this point. It should only be one wire with no splices between the switch and solenoid. Not much to check.

 

[bronco italiano]

T4, will do. Thank you.
BI

 

[DirtDonk]

You should have power to the I wire when the key is in the ON position. It's not powering anything in the relay, and it's not coming from the relay, it's just feeding in from the ignition coil.
But that does not have anything to do with the relay/solenoid not working.

When you jumped it, you went straight from the battery cable to the small "S" terminal where the Purple wire is?
With a volt-meter or test light you should be getting power on the Purple wire when the key is in START. If not, then the problem is the key or the wiring.

Are you just now installing the Centech harness? Or has this all been up and running for awhile and you just had a problem with the starter not working?
If it's a new Centech install make sure you're using the correct Purple wire. There are two and one is hot with the key while the other is meant to have a neutral safety switch installed in it.

Paul

 

[Broncobowsher]

Thinking about it, if the I and S wires are switched at the solenoid, the solenoid will be trying to pull in with the ignition in run. Start will do nothing. Solenoid may not pull in with the ballast resistor dropping too much voltage.

Pull the wire off the I post and check for power at both run and start positions. What does it do?

 

[Jfryjfry]

The I only gets power when the solenoid is engaged - it sends a full 12v to the coil as it cranks.
So if your solenoid is not clicking, the I post will not see power.

Check to see if you have 12v to the wire that is connected to the S post when you turn the key to start.

If you do but nothing happens, then you likely have a bad solenoid. Confirm this by jumping the hot side of the solenoid (power in) to the S post. It should click and crank So make sure it is in neutral!!!

Other things to check are the wires’ connections and the solenoid body's connection to ground.

 

[Rustytruck]

Make sure you have good ground connection between the body and the mounting bolts of the solenoid and good ground from the negative of the battery and the body. Ground is just as important as power to the solenoid when the key is turned..

 

[Broncobowsher]

If it starts by jumping the S post off the battery lead, the ground is good.
The I post does have power to it with the key in run, just not full power as it is after the ballast resistor. That wire is not dead except when the solenoid is engaged, that is incorrect. It is a bypass of the resistor during crank. It must be connected to the positive side of the coil between the ballast resistor and the coil to be able to provide power bypassing the resistor.

 

[Jfryjfry]

I can only speak to mine which is a 72 and the wiring diagram for it. The I post is connected to the positive post of the coil. The I post itself is open except when the solenoid is engaged at which point it is closed and provides a full 12v to the coil. When the solenoid is not engaged you should read reduced coil voltage at the I post but it doesn’t go anywhere because the connection inside the solenoid at that post is only completed when the solenoid is engaged.

Perhaps we are saying the same thing.

Bottom line is the OP needs to start by checking for full 12v at the S post when turning the key to start.

 

[DirtDonk]

Yep, I think you are. I basically said the same thing in an earlier post too.

To separate the two functions for purposes of this discussion then:
The "I post" itself, without the "I wire" does not have any power on it until the starter relay is energized with the key in START or when jumped.
The "I wire" itself has whatever voltage the ignition coils sees (anywhere between 6v and 15v depending on when and how it's being tested) anytime the ignition switch is turned to ON.
Therefore, when the wire is connected to the post you will see voltage when testing the post because it's being fed backwards from the ignition wire.
Pretty sure that's what we were all saying, but because B.I. did not specify whether he tested it with, or without the wire connected, we don't know if there is an issue with the wiring.
There is power to the coil, but no power as far as we can tell through the Purple wire from the ignition switch.
Starter relay, starter, grounds, battery all good because the starter spins when the relay is jumped.
Presumably the jump action was done between the battery and the S post, but that is not specified.

Paul

 

[bronco italiano]

Yes, jumped between hot battery side and "S" at solenoid.
Checking everything again tomorrow.
Thanks, BI

 

[bronco italiano]

Thanks a bunch CB members.
-Lock cylinder was also bad (besides ignition switch that fell apart).
-Starts as a bronco should now.
Sure appreciate all the assistance.
BI