Sometimes my ignition switch works and sometimes it don't. This is the second one I have put in. All of the electrical system is new. What eles would cause this, it's driving my crazy. Could there be a wiring problem. I have checked wires and everything checks good. Thank god for remote starters. Any help would be great!!

Scott B.
1979 F100
302 Auto

 

Bad switch? Neutral safety switch? ground? Could be a lot of things. Just have to keep searching, I guess. (Hopefully somebody knows more about this than I do!LOL)

 

Define "doesn't work." Do you mean you turn it to start and nothing happens, or what? Like previously mentioned, there are many things but you need to describe what's actually going on more so we can pinpoint it. "Doesn't work" could mean anything from the key not turning to different circuits not getting power.

 

have you added a ground to the back side of the silinoid? this stopped the issues on a few of mine.

 

If you have to ground your solenoid to get the truck to start then you have other issues as well. The solenoid grounds through the fenderwell which bolts to the cab and the cab grounds to the block through a ground strap. If you have to ground your solenoid separately then that ground strap is out. That means your voltage regulator and pretty much entire electrical system (headlights, etc) is grounding off that one wire now.

My point is, on a properly wired truck you shouldn't have to ground the solenoid casing separately because the sheetmetal is supposed to already be grounded and if it isn't, you're masking the real problem. I know that it solves the issue, but you at least need to make sure that ground wire is a pretty decent size because more than the solenoid is grounding through it now.

 

in a perfect world it would be working.....since its not this is how i would fix it. if we all had the money to go out and buy a new wireing harness that would be nice, but untill that day for me this is how i would fix it.

 

A ground strap is just a short length of braided wire that bolts between the engine block and the firewall. It's not part of the wiring harness. I only brought it up because without a ground strap, you're running more current through that solenoid ground than you might be aware of, so I'm pointing it out to help you avoid problems.

 

i see......

 

My truck does have the ground strap you are talking about. I figured the soleniod is grounded to the inner fender by the 2 bolts that hold it on. What I mean that doesn't work is that it has quit working now. My wiring is original but I replaced all electrical parts under the hood. The truck set for a while so I did this to not have any problems. You can turn the key over and everything works even the buzzer. But when you go to start the truck you get nothing. Sometimes it starts the truck and when it does it might start 10 or 15 times with No problem. And then it quits starting the truck all at once. Thats when I leave the key on and start it with the remote starter. This switch in it now is the original one. I bought another one and it did the same thing except it would start the truck alot more. So since I had the same problem I put my original switch back in. When it don't start you can hear somthing in the distributer or somewhere around it making a faint clicking noise. It could be something eles but it's in that area. I haven't checked the neutral safety switch yet nor anything under the dash except the switch itself. Does the switch have a ground on it somewhere that I'm missing. And is the neutral safety switch under the dash also. This is my first 70's model truck that I have had so I'm still learning where things are at. I mainly have had 48-52 model trucks which are 6 volt and alot less wires to deal with. I bought a good shop manual but I wanted to get your guys opinion's first, since you guys deal with them. Thanks for all the advice and I will start checking other things.

Scott B.
1979 F100
302 Auto

 

The "click" is probably the idle stop solenoid energizing, if it's a one-time click. That means your hot-in-run circuit is getting power. It's probably either the starter solenoid or the neutral safety switch. Next time it won't start, open the hood and remove the wire that's on the 'S' terminal of the starter solenoid. Carefully use a flatblade screwdriver to short the battery terminal of the solenoid to the S post and see if the engine cranks over. I'm pretty sure the neutral safety switch is on the side of the transmission itself but hopefully someone else can verify. On my '79 it is (C6 auto trans). Cars often have them on the column.

 

Neutral safety switch is on the top of the steering column about half way down and is activated by a little prong that is attached to the shift tube. It is made when the lever is in neutral or park

 

Depending on the year the neutal sfety switch will either be on the colunm or on the transmission. Somebody like Number Dummy would know. Yours may not be where it sould be for the year if the drivetrain isn't original. My 79 has the switch on the tranny. I did swap the tranny in but the plug in for the wiring was already in the engine compartment.

 

[rant on}
There's a couple ways to do this. :)

1) Fart around and change out parts until you stumble across the problem by
accident or the problem clears up by itself only to return some other time
and whenever it friggin feels like it. :) This is the most common method! :)
If you like following the crowd, this method is for you. ;)

2) Get a meter and chase down the trouble like you mean business. Or get
a friend that has a meter and knows how to use it (learn from him how it's
done) as he finds your problem cheap and easy as anything. Ain't got a
friend with a meter? Buy a meter and we'll teach you how to use it from
here. :)

Take your pick. ;)
Anybody got anything to add to the two methods listed by any chance?

Makes no difference to me which way you go, it's not my broke-down pickup
or my money being spent on new parts as some weird form of gambling.

So maybe I should just shut the @#$% up? :)

Alvin in AZ
ps- a cheap analog beats the crap out of even an expensive digital meter
for chasing electrical trouble, but either will work ...YMMV
{rant off}

 

Huh! you learn something every day! I've had a bunch of these and every one had the switch on the column (column shift autos). Just goes to show what a good resource this board is.

 

change your solenoid out same thing happened to me
i did not have a remote starter so
i started it by leaving the key on and start it by using
a screwdriver on the solenoid