Just wanted to say thanks to everyone for the posted labeled pictures on the thread. I have a short I have had to deal with and the labels sure help in checking out what I have on the truck.

 

Hey Sere,
So.... Are you declaring victory on the 12V Re-wiring you were doing?
Everything working ok?

Ben in Austin
1950 F1

 

Not yet Ben. I'll definitely close this out when it's all done so folks can use it for future reference if needed. I tried to check for spark today and got nothing when I hit the push button........ Lights all work (well I had to figure out why the rear lights were not working first.)


Turns out the PO had towed it with a tow bar and rigged the lights up for it and never put it back together. Plus you can see the original harness goodness around the brake MC.
Back to the mission at hand: I don't know why I get nothing at the push button. I can arc it across the solenoid and it will turn (and it even has spark) but nothing at the push button. I had to do some adjusting to the alternator and when I took the bolt off the back I heard something fall inside.......


The nut was only glued on and it came off. Now I have to wait for that to dry, and meanwhile I put on a new push button
. I fear that it's a wiring problem though and will bounce it up against an old diagram that Julie had posted

 

I may be asking for some more advise if I can't beat this push button problem though. You guys are great and I appreciate the help! I'll keep you posted.

 

Don't use Julie's diagrams, there are too many problems with them. For one thing, as is noted on his diagram, "all start buttons are continuity type, not grounding type". That isn't what 48-51 trucks used, and they didn't use a 4-terminal starter solenoid. You have a 48-50 truck (you should say so in your Signature), and those use a grounding type starter button. But I also see you have a new-looking solenoid; is it for a 48-51 or a later-model truck? The difference is, a grounding type button grounds the small terminal on the solenoid to energize it. Later model solenoids need power to the terminal to pull it in.

You can tell which kind of button you have by looking at the back of the button. If it has two wires, it is a continuity type for '52-on, one wire is a grounding type.

Then you need to verify which type of solenoid you have. If grounding the small terminal starts it cranking, then you need an early (1-wire) button. If jumpering from the battery to the small terminal starts it, then you need a 2-wire button.

PS there are some errors in those diagrams, don't use them. Use the diagrams in the workshop manual. If the rest of the truck's wiring looks like the brake light circuit, I don't know that you should be connecting it up to a battery.

 

Thanks again for the help. I won't use the diagram but for the life of me I can't find the push button on the diagram from the manual.

1949-50

I'm not the greatest at deciphering these but I'll keep at it.

The "kit" I bought was suppose to be specifically for my truck 1949 F1 226 (I'll do my best to get a signature block, tried a couple times before but my computer skills are lacking I guess). I have a 3 post starter solenoid

As indicated, the red wire on the + side goes to my circuit breaker (same post as my ignition goes to, see next photo) and the red wire in the center connects to my 2 pronged push button.


The alt/coil/circuit breaker/12v reducer all connect to the BAT terminal. The radio is connected the ACC and ground is on the other post and connects to the grounded side of my gauges. The radio/ground/circuit breaker wires were connected to their perspective terminals when I received the truck.

 

Here is the push button (installed a new one just to see if it was the problem but have been unable to check it until I get the alt back together.


Red goes to small terminal on starter solenoid and green is grounded.


When I arc from the + side of the starter solenoid to the small terminal marked "push button" then it will crank. I have not tried arcing any other configuration.

I did have it running with a 3 pronged solenoid and 2 pronged push button before when it was still 6v. And yeah, I'll be replacing some more wire today if I have time. Soon he'll get a new harness all together.

I did install a fuseable link in the main line coming from the alt. Napa's wiring book had some great info about fuseable links. It recommended going 4 sizes smaller and said there was no difference in the type of wire. It went into pretty fine detail about the temps and protective coatings on wire etc. I went with 14 gauge for my 10 gauge main wire coming from my alt and connected it with 10-14 gauge butt end type clamps. My shrink wrap wasn't big enough so it got taped instead. I'll be putting another one in between the + side of the solenoid and the circuit breaker.

I have tried adding a wire from 'BAT' terminal of the ignition key to the push button and it tried to crank with the key off as soon as I connected the battery. I tried the same thing from the circuit breaker with the same result.

Thanks again and please keep the feedback coming.

 

If your engine cranks when you connect a positive source to the small (push button) terminal on the solenoid then you need a positive power source for your push button switch. I assume from your description that you are a negative ground system? If this is the case the green wire on the push button needs to connect to a positive source, not ground. If the engine cranks when hooked up this way when you are not pushing the button you have a shorted switch.

 

Here is the correct wiring diagram. The starter button is at about 11 o'clock on the diagram.

 

Pete's diagram is correct. But remember it is for a positive ground system. If you have a negative ground system the push button does not connect to ground.

 

I'm not sure that is correct. If you follow the diagram all that you are doing is completing the circuit to the solenoid. Ross, help me out here please.

 

Wrong; the alternator big wire should be connected (with the main power wire from the battery) at the circuit breaker.

The coil should be connected to the IGN terminal on the ignition switch.

"The radio/ground/circuit breaker wires were connected to their perspective terminals when I received the truck. " -- I don't know what that means but there must not be any ground wires connected to the ignition switch, period.

That is not a stock starter switch, it may work fine if it is a momentary contact, Normally Open switch. You need a '52 starter button to work with the solenoid you have. (two terminal, one connected to power)

 

Pete, most 12 volt solenoids ground through the bracket so you need positive current to the "s" (crank) terminal to make them engage. In the diagram below you can see that the solenoid grounds through the bracket a positive voltage at the "S" terminal completes the circuit. The "I" terminal supplies 12 volts to the coil during cranking. Not all solenoids have an "I" terminal, and it is not used on mos electronic ignitions.



This is for a positive ground system.

 

The only thing I'd add about Rimrock's diagram is that the wire shown to the coill from the ignition switch is really from the downstream side of the ballast resistor. Otherwise the wire from "I" terminal does nothing.

 

Ross, thanks for the diagram sure does make things easier. One observation, shouldn't the power going to the start button come from the "I" terminal rather than the "B" terminal? I don't know how ford did it but as shown you could crank the engine while still having the key in the off position.

Edit: I just tried mine and it will crank with the key off.