OK, before I forget:

1986 F350 460, 4bbl, C6, Dual Tanks, etc. Well maintained, all the bits and pieces work...I keep it in good running order.

Now, on to the issue:

I got in the truck today after a quick run to the store and when I turned the key...nothing. Not even a click! However, I had power to all the accessories and lights, so It was not a battery problem. I fiddled around under the hood and did not see anything loose or out of the ordinary...just no starter when turning the key over.

OK, no worries...use the screwdriver trick to get her started up and deal with it later. She started right up (starter turned over just fine and at a good RPM). Got back in, waited for her to warm up, and off we went....for about 1/2 mile when she died again.

OK, pull over to the side of the road and twiddle some more. Nothing. Get back in, and notice a fuse laying on the carpet under the pedals. Hmm...only one slot open, so I put the fuse back in (and pushed on all the rest for good measure) and give it a spin....nothing (no starter, nothing). Even the screwdriver trick is not working. While the fuses are not labeled per-se on the truck, it appears to be the dash light fuse (no instruments when it's pulled out).

Get out the test light...power to everything, but no power to the energizer wire on the starter relay. Coil has power, there is spark when cranking, and the dizzy is turning.

OK...tow home. Figure it out later.

So, I get home and start to thinking....no starter when turning the key, ran for a while but nothing after a bit, have spark and cranking....so it must be fuel (if you have crank, spark, and fuel, it *must* turn over).

Now....what would keep the starter from engaging when there is battery, and also kill the fuel pumps??? (I'm assuming that's what happened, and I was running off of fuel in the bowl for that 1/2 mile or so). I checked all the fuses both in the cab and under the hood and all is golden. Maybe the emergency shutoff thing? I haven't checked that.

Anyways...I'm going to get some sleep and think about it some more. If any of you have anything to add that it may be, please let me know. I really want to get my truck back and running soon.

Thanks everyone!

Dan Martin
1986 F350, Crewcab Dually, 460, C6

 

Fuel Pumps has a bad way of leaving you stranded, fuel cuttoff switch means just that. Ignition curcuit goes through the electrical Ignition Switch, it also makes the starter turn over.....fuel and fire makes the engine run.

 

There is a relay under the hood on the passenger side of the truck near the battery. When you turn on the ignition do you here it go “click” and energize?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>

 

Cole,

No click...no power coming from the key to the starter relay either.

Dan

 

Locknkey,

Thanks for the info, but I'm not sure I understand your reply. Does the emergency cutoff switch also cut power from the key to the starter?

I don't have my schematic here with me today, or I would look it up myself...but I would imagine that it very well could.

Dan

 

If you are making a short at the starter soleniod and it is not working then it can be only 2 things, a bad ground connection to the block or starter ot bad terminal and or connection at the battery. Nothing in the ignition system comes into play here. If you can not get the starter to engage that by the good old screw driver trick then it has to be that. If you look you will see that there is a pos from the battery to the starter soleniod and then from the other side of the soleniod to the battery, Check those connection FIRST. Also check the Neg battery connection to chassis ground. You do not need to look at all that other stuff as that only applies to ignition and not firing up the starter if you are manually engaging the starter by direct connectiont at the soleniod. If the connections are good then replace the soleniod and you may also want to look at the fuseable link for any hot spots. If there is a problem there it will act very intermittent and then die. It really does a number on the ECC and resistance will change as it gets hotter.

 

You might also look at the neutral safety switch or if it's a manual tranny the clutch switch.

If it's an automatic try holding up on the shift lever while turning the key, sometimes after years of use and bushing wear it does not make contact with the neutral safety switch in the park position.

 

First things first, He was running and it died on the road....he said at the time it cranked useing the key, now he also said that all fuses are good, both under the hood and in the fuse box. I suspect that the problem is in his Electrical Ignition switch mounted on the steering column....after thinking about this, it seems logital to check it with a multimeter to see if he's getting the 12v from the starter curcuit from the ignition switch (the electrical one, not the key switch cylinder), then trace out the curcuit from there to see where the problem is...but I would guess its the electrical ignition switch.

 

All,

Thanks for the great input. I think the Neutral Safety Switch is a great idea that I didn't think of!

Let me re-state some of the points of the issue above:

1) Key never worked...used the screwdriver-over-the-starter-relay trick to get it started.
2) Stalled on the road about 1/2 mile away. Probably starved for fuel as there was fire and starter turned over.
3) No power to the energizer wire to the starter relay, but relay worked fine if energized manually.
4) Probably no fuel in the carb bowl, but there was fuel in the visible filter I have next to the coil (but no visible flow now that I think about it).
5) I'm still puzzled about the fuse falling out of the block and on to the floor. It was the fuse that controlled the dash lights and power. I find it too much of a cooincidence that I'm having electrical issues now with the key/safety switch/shutoff switch/fuel relay to ignore that detail. I think something somewhere else has fried...

Again, thanks for the constructive input! I'll keep you posted as I find out more details.

Dan

 

Check your ignition box. Generally when they go bad you will get crank but no fire. But with the sudden onset of multiple electrical problems you might have fried your brains. Yours and the trucks.

T. Roberts
UFD Local 1147

 

91f250460

I've confirmed I have fire, so the box is fine. My issue is no starter (power to the engergizer wire from the key) and no fuel pumps. Aside from that everything works great!

I thought about the neutral safety switch, and that would explain why the starter won't engage, but not the fuel pumps. I really think it's the emergency cutoff switch (inertia switch). If only I can find it on the truck....

Dan

 

Found the inertia switch on the firewall/tunnel inside on the passenger side. The switch is in the correct postion, so that's a bust.

I think tomorrow will be spent with the electical schematic and a test light to track down the problem. *sigh*

Dan

 

mistakenID wins! It was the Neutral safety switch. The Pink/Blue wire (starter relay energizer) had power going into the switch, but none coming out no matter the position of the switch. About a $30 part from NAPA, and about 20 minutes to replace (climbing under the truck to do so, but no big deal when following the directions).

I replaced the ignition switch as well (it was only $14, and I had the steering column apart to get to it to do the testing anyways). Cheap insurance, as they do wear out over time.

Anyways, thanks for the help everyone!

Dan