Hot Rods Technical Electrical Issue on Ignition Circuit

1934 Ford Pickup converted to 12 volt and GM style 3-wire alternator so that I can run gauges and an idiot lights. Same starter solenoid as on my '61 that Ford used from the mid '50s-88.

Went to start the truck, and got low current, then no current when I turned the key and lifted the ignition lever. Normally I can hear the fuel pump come on after lifting the ignition lever and before hitting the starter button. Now, nothing. No fuel pump, no gauges register.

Battery is fully charged.

Thinking it was the starter solenoid, I replaced it. When I turn the key now and lift the ignition lever, at first I heard the solenoid click; now it buzzes as soon as I lift the starter lever.

Where should I begin my diagnosis? Bad ignition switch? Bad starter solenoid?
Not sure what my next step should be?

Thanks for the guidance.

 

Did I inadvertently hook up the replacement solenoid wrong? That is, switched the wires on the small posts? The solenoid should not have juice going to it unless I have the starter button depressed. Just wondering.

 

Your battery should be registering 12.5 to 12.8 volts across the terminals as it sets non-running.
Check the current reading at your ignition switch, starter solenoid and coil.
Give results and we’ll go from there.

 

Might check for clean, tight battery cables and ground connections.

 

When I turn the ignition lever up in the On position, why am I hearing a buzzing from the solenoid??? It seems it is getting power. Why? Am I correct that no power should be going to the solenoid unless I have the starter button depressed?

Right or wrong?

 

There are two different types of three terminal solenoids.
One actuates when grounding. The other actuates with a hot wire. How much power do you have across the battery terminals????

 

13+ volts

 

yeah, you could have switched the small wires, then it would be trying to start when you just turn on the ignition.

 

purple should be on S, brown on I, if it's wired with the normal color code. Looks right.

The battery posts might be iffy, though.

 

Ok you have plenty of power. Now you could have bought the incorrect solenoid. See if your starter button is grounding when depressed or does it engage a voltage to the center post of the solenoid.

 

Correction. After seeing Your solenoid has four posts. Your running a hot wire button.

 

Not sure what that means. I have limited electrical knowledge.

I had two solenoids in my shelf. I thought both were for my '61 which is the same as this truck. But it might have been for my 1990 pickup that I sold. Ford made a change in the solenoids in 1989, so I could have the wrong one.

Is it possible the two small posts are switched???

 

look at the letters on them. S should be start wire, I should be the ignition ballast resistor bypass.

 

I hooked them up same as before.

So where is the solenoid drawing power from when I lift the ignition lever (but don't have the starter button depressed)?

How can I track that down?

 

Do you have a voltmeter or at least a test light? I would disconnect both small wires at the solenoid. Turn the ignition on and check to see which one has power. That should be connected to the I terminal on the solenoid. Now depress the starter button/lever. The other wire should have power on it with the starter button depressed and goes on the S terminal.

With that said I think you may be compounding your original problem. If you aren't getting ignition power, replacing the solenoid won't fix that. You need to do some troubleshooting before replacing parts. If you don't understand electrical you may want to find someone who does. Even if you have to pay him it may be quicker and ultimately cheaper.

 

Is the solenoid labeled S and I on the small posts?
The change Ford made was to eliminate the I terminal that feed full 12v to the distributor on point systems.
If you had the I and S wires switched you could be back feeding 12v from the Ign circuit to the solenoid.

There are also 4 wire solenoids used for large trucks and other applications where one small terminal is positive from the start terminal on the switch and the other goes to a ground though a thermal overload switch on the starter or interlock such as a clutch safety switch or neutral safety switch etc.

 

Not familiar with your solenoid but this may help you understand the leads running to yours.
Exactly what problem were you having before changing out the old solenoid?

 

Exactly what problem were you having before changing out the old solenoid?

See original post:

Went to start the truck, and got low current, then no current when I turned the key and lifted the ignition lever. Normally I can hear the fuel pump come on after lifting the ignition lever and before hitting the starter button. Now, nothing. No fuel pump, no gauges register.

 

That would have nothing to do with the starter solenoid other then a possible bad connection on the battery cable side.
Looking at the battery picture I would start by cleaning both positive and negative cables and posts.

 

The headlights come on- so the battery posts and terminals may not be great, but there would be enough current to run the fuel pump and see two idiot lights glow, I would suspect. I get nothing when I lift the ignition lever.

There is something else blown here or shorted out. Dunno what just yet.

 

Sounds like your '34 is using the stock ignition switch with the push button (the stock switch grounds to the dash when pushed). If it is you need to make sure you're using a insulated base solenoid, if you're using the grounded base one it will try to start or click (depending on how you wired it up) when you turn the switch on. I used a 12v one on my '47 that's a insulated base and the stock push button grounds the solenoid for cranking.

These are Standard Ignition part numbers (maybe older numbers)
Insulated base SS-587 and it's 3 lug
Grounded base SS-581 and it's a 4 lug

You might want to post what wires go where on your solenoid you have on there now. Because purple usually means starter solenoid wire (on GM).

 

You could have 13 volts but no amps due internal bad battery. It doesn't take much to turn on lights. Have the battery load tested if you are not sure about it.

 

I wondered about that. The lights were not very bright. I will have it tested. Thanks!

 

While it is out I would clean those terminals really well and eliminate rust, add some dielectric grease and tighten everything back down. Also, check the end of your ground cable for the same corrosion.

 

Interesting, the “click”you heard couldn’t be from the starter solenoid, when you lift your switch, that should just provide 12 volts to the push button, which when pushed provides 12v to the solenoid. When the solenoid gets energized, it then passes the voltage through to the starter.
Did this start correctly for a period of time when converted to 12 volts? I assume it’s also negative ground now?

 

Run it for 10 years with no problem, last five with the GM alternator. 12 volt system, 12 volt conversion to the starter as well.

Will take to store and have the battery load tested. Combination of bad ground(s) and no battery amperage? We'll see.

Thanks for all the guidance here.

 

I am wondering if the solenoid is fused up. I can test. I have had that happen before on another vehicle, especially with the cheaper solenoids. Never a problem with say Motorcraft, but at least twice with some of the cheap China stuff.

But there again, it may have been equally caused by faulty grounds.

 

The "I" post is only for resistor bypass. Nothing is connected to it if you do not have a ballast resistor on the rig.

Stock early Ford starter pushbutton does go too ground to activate the solnoid.

Looking at the photo of your solenoid and comparing it to one I have makes me wonder if you don't have the solenoid wired wrong. I can't tell if you have it mounted upside down in the frame or if it is the angle that the photo is taken from but from what I can see the issue is that you wired it backwards as far as powe in and out on the large posts go.

 

I don't think this is correct.

This has the starter side and battery side reversed.

Should be like this: