Alright guys Im at wits end trying to diagnose a NO start issue.

77 F150 400, 2wd, auto

Ive been working on a major tuneup, I went through and replaced the carburetor, changed all fuel filters, tune-up including oil change, tranny change, plugs, wires, cap and rotor. Plus I changed out most of the Emissions parts, EGR valve, PVS, air check valve, and new thermostat, coolant. I may have forgot something that I did, but as you can tell I went through it all to get her roadworthy and reliable.

I was done in the AM and it fired up, I adjusted the carbs appropriately and it sounded excellent, no hesitation, no shimmy, no problem.
I shut it off went to work and came home and it wouldnt start.

All that happens is the power comes on, dash, headlights, no sound, no clicking, no attempt to fire.

Im thinking either starter relay? starter solenoid? OR starter.

Im going to go through and check all connections and clean them up this morning, that could be an issue too, maybe a connection came disconnected or possible a bad ground connection.

This has happened about 4-5 times in the past 2 months randomly.

What do you guys think?

Anyone else have a similar issue?

Any help is greatly appreciated, last thing I want is to be in the boonies fishing and get stuck with no cell service...

 

Both terms refer to the same thing.

Remove the wire from the 'S' post of the solenoid (RED with BLUE stripe), and measure the voltage it delivers while a friend holds the key in START. Report your results.

 

I had this happen to me one time, ended up being a ground strap from the Engine to the chassis. If there is no click at all then you are not getting power to the solenoid for whatever reason.

 

FMC, I followed your instruction and it recorded a 0.0-0.01.

Here's where Im confused, I pulled off the wire, did the test with key being held in start position, got the above results.

I put the wire back on, and was just testing the other connections for the hell of it, all I got was the 12.4V coming off the positive battery terminal.

I touched the tester to the S post with wire on, and other to ground while it was in start position and it started to crank, so I had it turned off immediately. I went into the cab, turned the key and fired right up.

Gotta be the relay right? maybe its failing or do those just go out when they need to be replaced?

What do you guys think?

I'm starting to think paranormal, the story is the truck was bought from the original owner who died in or near it. OR it could just be a relay, hope its the relay.

 

you touched your meter to ground on the solenoid, or on the body? I know I used to (still do) use a pair of needle nose pliers to touch the s-post and the out-going(?) post on the solenoid with the key on, if it turned over, solenoid is junk. Probably not recommended to do that anymore.

 

The signal leading to the 'S' post of the solenoid comes from the ignition switch through the neutral safety switch. If you have no power here when you otherwise would expect it, then the ignition switch and/or neutral safety switch is bad, or the neutral safety switch is misaligned. The latter is more common; alternatively, sometimes the shift lever has enough slop that the transmission appears to be in PARK when it's really in REVERSE.

The first part of your reply indicates you're not getting a trigger to the solenoid, which doesn't say anything about whether the solenoid needs to be replaced. It's not quite clear to me based on your description what exact steps lead to the truck cranking when you touched the meter lead to the solenoid - but if the 'S' post was shorted to the battery in any way, that can make the solenoid engage.

Maybe it's just a typo in your post, but your description is incorrect. Touching the 'S' post to the battery side of the solenoid is indeed a common way to troubleshoot the solenoid, but if it turns over this way, the solenoid is actually good. Touching the 'S' post of the solenoid to the starter side of the solenoid (assuming the 'S' post is otherwise disconnected) won't do anything (not sure what you meant by "out-going" post, so I've described both).

 

Whoops, thanks for the correction. I do better with these things right in front of me.

 

this was the problem. it looks like its in Park, no visible slop, but just giving that little extra push when putting it in park solved the issue. now I know I wont get stuck somewhere with it being a starter or relay issue.

I think the reason why it started while testing is because my daughter grabbed the shifter and problem pushed it further into park. makes sense now.

Problem solved. Thanks FMC400.

 

Those NSS tend to get sloppy overtime, just one other reason why I hate slush boxes and advocate for a third pedal.

 

Awesome, glad to hear you got it worked out.