My 73 f100 (360) will not start and I am running out of ideas. Any help would be appreciated.

The other day I turned the key and I heard a rattle from what sounded like the starter solenoid. So I changed it. But nothing changed. The battery it fully charged. So I took the alternator and the starter down and they both work fine.

So I am wondering if it might be something else. I know the ignition switch is loose and the shift lever needs to be in a certain position to allow the truck to start.

So my next guess is to change the ignition switch... and if that isnt it I wonder if it might be the pin neutral switch or something to do with the steering column.

 

Maybe play around with the shifter when starting to start it. I know you can bypass the NSS to check if that is it but I don't know how to do it.

 

I am guessing the rattling you're hearing is the starter solenoid, that noise can be caused by low voltage being delivered to it. I describe it as a fast-clicking sound.

Jump the large positive cable with the small screw terminal where the red/blue-stripe wire connects (the terminal closest to the front of the vehicle) and verify the sound is coming from there. Numbers 3 & 5 in the drawing.

Jumping those connections simulates turning the key to START (but without the ignition system having power) so be sure it's in Park or Neutral and be sure the brake is set.

If this is where your problem seems to be, I would begin by removing and cleaning all the primary cables... battery <-> solenoid, solenoid <-> starter, battery negative <-> engine block.

Clamp-on, temporary-use terminals/cable ends that some people use allow moisture into the insides of the cables, this creates corrosion and eventually renders the cable useless.

Chinese-made solenoids have a solid history of sometimes being bad right out of the box.

From Franklin2's diagrams:

 

What have you done to verify this? 99% of the time, "solenoid chatter" is because of low battery voltage that will only show up when the solenoid tries to connect the starter to the battery. In other words, the only way to know your battery is good is to load test it. Was this what you did?

 

Grounds grounds grounds and battery cables before you throw other electric parts at it, if it is clicking it getting power, just not enough.

Borrow a different battery and clean and double ck all your connections.

 

Jeff - Thanks for the post, this is something I forgot to write.

Was gonna suggest measuring voltage at the battery while the starter is cranking (or trying to crank).

 

Thanks for all the info.... but still no go. Here is what I did today. Pulled the starter and took it in to a local shop that specializes in starters,alternators etc... they tested the starter and it ran. But needed some work. So it is rebuilt now. I reinstalled it and nothing. I replaced the battery cables and the starter cable.

I have had to work the shifter for a while. I can turn the ignition 2 clicks and have the brake light in the dash light up. This is normal, and if I turn one more click... it should start. But still no go.

I tried jumping from the neg terminal to the soleniod closest to the cab. Nothing.

Battery voltage has been checked. All good. But I may try a different battery as I am running out of ideas.

Would this problem be caused by a poor ignition switch or a neutral switch in the steering column?

 

Was this loaded or unloaded?

By "problem," do you mean relay chatter with the key in START? If so, no, and the problem still lies in the suggestions so far. If you're not getting any click at all with the key in START, then yes - at which point you'd check for voltage at the 'S' terminal with the key in START.

 

Yes a bad safety neutral switch will kill it, it is under the dash on the steering column.

 

If you jumper the solinoid and it does not turn over, you either have a bad ground, bad positive wire to the solinoid, or to the starter, or no load capacity in the battery or a bad starter. You can very very cheaply buy a solinoid bypass switch that clamps on the terminals, and is only closed when you supply pressure. at that point the system will turn over if it can. If not one of the above is your problem. Whether it runs or not, the engine will turn over if you supply 12v to starter, starter if properly grounded and the engine is properly grounded.

Check your ground. Check your battery just because it has 12v does not at all mean it is good.

 

The battery tests good but I have not tried testing the voltage when trying to turn it over. What should the reading be when I do this?

 

I replaced the ground wire and had to attach it to the valve cover.... would this be a bad ground location? The old location was a 3/4" bolt on the block but the new cable was only a 1/2" hole so I had to relocate it. I will try putting the old ground wire back on. Will it hurt to have 2 ground wires on?

 

No voltage maters but not much. They will turn over at 9.5 volts. The ampreage is what maters. A load tester simulates the electrical work of the starter motors resistance, and the work of moving the heavy hunks of metal around.
I hope this makes sense.

 

Your battery when fully charged should show 12.7 volts, full of water, and at normal outside temps.

Here read this and you will never ever wonder if its your battery again.

http://www.pureenergysystems.com/PES...tery_Bible.pdf

 

So the battery could be screwed and I wouldnt know it.... hmm. When I put the jumper cable on both terminals they spark like crazy. So I will have to get another battery. Can I use one of those units thats boosts cars? it acts like a battery doesnt it?