I’m having some starting issues on my 77 f150 4x4. It’s a 460 auto truck. I have swapped out the starter, battery cables and solenoid. I’m really leaning towards the ignition wiring itself and I would like to bypass the key switch temporarily to eliminate or pin point what is actually going on. A previous owner hacked the hell out of the wiring under the dash. I do plan to rewire in the future but for now I would like to just turn the key to ignition on and press a push button switch and see if that fixes it.

what wold be the best way to go about this?

 

Just get a wiring diagram and, go over the starting circuit wiring to see if it's hacked first and fix it. These things don't have complicated wiring systems. I can't remember 100%, but I think they run reduced voltage to the coil, through a high resistance wire, when it's running and only give it a full 12V at start up. If you run 12V constantly through a bypass switch you can cook the coil. Might be the switch on the column also.

 

Why add a hackjob on top of a hackjob?

Do the job right once and thank yourself later. Clean up the wiring mess with the aid of a factory wiring diagram first and then see what you're working with.

 

About the same amount of time invested in this conversion, you could very well fix the issue and have it operating as designed. The reliability of the factory system will probably be greater than one of “aftermarket” design. Not knocking your abilities, but probably take a similar amount of time to fix it right.

 

So you're having starting issues, but what exactly is it doing? Curious if it's just something simple in spite of the PO hacked wiring.

Is it cranking but not firing? Is it not cranking at all? Does it click when you turn the key to START, or do you get nothing? Does the starter spin slowly, or quickly?

Just some areas of curiosity. I've connected a push-button switch on a Bronco and it was strange, but strangely modern-cool too. However, after about 25 starts the very expensive push button stopped working, so that experiment went totally out the window.

Good luck.

Paul

 

Well the reason I’m just wanting to push button and not fix it correctly is I’m planning to ditch the entire body. When I do that I will put a new wiring harness in the truck. I just want to get thru the winter with it. It’s not a truck I’m daily driving. I don’t want to put anymore money into the current set up.

The starter is dragging and sometimes doesn’t fully engage. It could also be the flywheel but I really think it’s not getting the right voltage.

 

I suspected the neutral safety switch as well. When I went to fix it is when I noticed the hack job. The safety switch wasn’t even hooked up. That’s when I noticed every wire going to the column has been cut and taped. It’s just a bad situation all together.

 

Then I would start with the under-hood stuff first. And because it's an entirely separate "harness" and would be worked on by itself anyway, it's a good idea to upgrade it now and you can continue to use it no matter what other work is done to the truck.
Body off, body on, new chassis harness and components or old, the starter cable and battery cables could be renewed and upgraded now, to see if that fixes your low voltage issue.

The ignition switch to NSS wire and NSS to starter relay/solenoid wire won't have any effect on your starter not spinning fast or engaging consistently. Usually anyway... Sometimes the relays get old and don't pass all the voltage through to the starter, but usually they just fail to click altogether.
If that's what you meant by dragging, then that's the job of the battery, battery cables, starter relay and starter cable. So unless you're going to be relocating the battery and/or fender mounted relay to new locations later, you can spend a few bucks now for new cables. And unless you're going to be swapping in a different engine family, a new starter might be called for anyway if the old one is causing the trouble.
In fact, I would start with the cables only anyway, and leave the relay if it's working for now. Reason is that so many of the new ones are crap and start having their own problems quickly. Really messes with diagnosis.

A new set of 2 gauge cables, including a ground cable with additional10ga ground wire for the body, and you're good to go for a few decades.

That's what I would do anyway, before messing about with a new ignition switch/starter switch setup. Even if it does not fix your issue, it is usually a necessary upgrade for any project and only costs a little bit of money and almost no time.

Good luck!

Paul

 

For what it's worth, I fried the tiny battery/starter cables on my truck back when I first got the truck due to a no-start issue I had. Once I figured out what was causing the truck not to start (broken wire on the magnetic pickup) I was getting very slow cranking due to the battery cables. They were actually heating up and melting with each cranking attempt regardless of how long I cranked the engine. Anyway, I installed some very large 2/0 cables and my starter cranked faster than it ever did prior to me melting the original cables. I haven't had a starter related issue since then and that was at least 3 years ago if not longer.

 

I'm a big fan of "overkill is just enough" when it comes to battery and starter cables. Those 2/0's sound like just the sweet spot for your setup.

That's why I usually recommend 2ga now as a basic upgrade. Sure, the old 6ga did their job when new, and sure the later 4ga cables are sufficient for most needs. But hey, since the next size up is easy to find and only a couple of bucks more... Overkill it!
I use 1/0 on my trucks (one size smaller than Doosenberry's), but it's not necessary for most who don't build their own or have a local supplier that can make them custom. Off-the-shelf 2ga is great stuff.

Paul

 

Here you go, no key... toggle switch and push button simple.

 

thank you this is what I was looking for. I’m going to just push button the start side under the hood and see if that’s where the issue is. If that fixes it then great. If not then I will pull it out and reconnect the factory wiring.

I did replace the battery cables last weekend along with a new solenoid. As far as the starter goes, I had the starter on another 460 earlier this summer and it cranked the engine just fine. Actually sounded like it was supposed to. Quiet engagement and sun the motor easily. So I know the starter itself is good.

thank you all for the help on this I really appreciate it.
I know it’s stupid to do a hack job like this but it’s all going to be scrapped in the future. I’m not even sure if I will keep the 460 or do a late model swap in the future.

 

Found a shorter way to go...

"As for the push button start switch. If you don't want to repair the wiring to use the key switch, one wire from the push button needs to go to a constant 12 volt hot and the other wire needs to go to the small "S" terminal on the starter solenoid."