has anybody heard of a reason a truck won't shut off that doesn't deal with the ignition switch.... I am struggling with why my switch works in all positions except off.... i have had the truck running with the switch off of the column, in my hand, and moving the slider to every position available and in between with absolutely no sign of wanting to stop running....... my shop manual has a diagram of the switch for testing continuity, but I'd like to compare my wiring harness to something... some of the slots on my harness have no wires.... I could go out and compare to the 84 F-150..... what do you guys think

 

sounds like u have a problem with carbon tracking . so what is happing is that there is a line of carbon running along the track causing the truck to have power even tho u shut it off . ford did have a problem with the swich going bad with this problem . id just change it out they are faily cheap to

 

it is new switch.... I'm wondering which circuiting route gets de-energized to actually stop the ignition circuit and make the truck stop running and also de-energized all power from the battery... wire to ignition module?... battery to coil link?... I read somewhere where the ballast resistor being bad might contribute... I totally convinced that my new switch is working except for the off position... the old switch did have some play where you had to rotate back a little after start to get the instrument gauges and radio to work..... this new switch has very distinct detents for each of the key positions...... but off ain't off.... I'm thinking about installing a lever that pops off my coil wire so I least I can turn it off from inside the truck.... thanks again

 

Hummm sounds like to me like the switch (not ign sw) iThe rod s in the wrong detent on the switch.

 

The '84 switch might be different, but it should be close enough. Get a Haynes manual and use the wiring diagrams in the back to diagnose the problem.

Do you have a tilt column?

 

non-tilt column...... did some wire chasing this weekend... everything seems to agree with my shop manual on where to be hooked.... the truck has an ammeter.... the ammeter does not work.... I haven't got behind the dash yet to see if its hooked and dead or not hooked up and by-passed.... the wiring diagrams indicate power running through the ignition switch with the ammeter set-up.... could the wiring to the ammeter be suspect.... I was performing a charging system test per the manual and was setting my RPM... I dropped the ground probe, it touched the truck and out went my ignition module.... truck shut right down....now thats one way to turn it off...... kinda expensive tho

 

Some people on this BBS have sworn that they had non-tilt columns, only to discover later that it actually tilted, so I just want to be SURE: is the hole where your blinker lever goes a straight up-and-down slot, or is it sort of triangular with a point to the front (dash)?

It still sounds to me like the ignition switch isn't really hitting the OFF position. Do the radio & ventilation fan shut off? Do the fuel & temp gauges die?

A fault in the ammeter circuit wouldn't power the ignition or anything else - it runs straight to the instrument cluster, so it's "on" all the time. It just shows the voltage across a shunt (calibrated resistance), so it can't cause this unless there's some SERIOUS shorting going on inside the wiring harness. If you get desperate and want to be SURE, cut the Y/LG and R/O wires near the battery along the R inner fender in a way that will allow you to reconnect them later.

 

oh yes... the loop to the ammeter..... I do have the haynes manual wiring diagrams... 654 Y/LG has a splice on 37 Y... I believe the 37 Y 's are both power connections to the battery... traveling along 37 Y past the splice there is a symbol -< <- labeled C-610... is this some sort of diode to prevent backflow of power... I guess I'm thinking since the ignition switch harness has connections to both starting and charging circuits, somewhere downstream of the ignition harness power isnt getting completely cut-off.... by the way, straight turn signal slot, non-tilt, I read the threads on people discovering tilt and it made me go look...... besides I've had the thing apart too many times now...

I should mention, previously I had the truck running with the connected, brand new ignition switch in my hand... I moved the switch slider manually with a screwdriver in all positions and no where did it want to shut off... once I thought I heard a electrical grounding noise, but cant be sure.... one thing I did was sand the inside fender at the regulator.... the previous owner put a thick coat of bedliner type paint on the inside fenderwalls.... it defintely wasn't getting grounded....bought new regulator for kicks and no change...

the gauges/radio/fan all work in run and acc and all go off in off and lock....... the old switch was tuchy, you had to rotate it back a fuzz after starting to get everything to power up.... the new switch cured that at least...

 

found this in the forum archives........ this is what I am thinking is happening........





slikness
Posting Guru


Registered: Jan 2000
Location: Durham
Posts: 1085
View User's Gallery RE: truck wont stop
I believe some of the early '80s Fords had a diode in the altenator circuit. If the diode burns or short out, it will continue to allow current to flow through the ignition system allowing the engine to run with the key off. Check your altenator circuitry.

'82 F150 2WD w/351W (orig 300 I6)
Slik



__________________
Slik
300-I6 to 351W

 

No, there's no diode outside the alternator, and a bad one inside would only drain the battery and burn up the alternator. The indicator circuit runs thru the bulb in the cluster, which provides enough resistance NOT to power the ignition or anything else.

With the engine running, but the ignition switch off, try unplugging the switch. If it dies, the switch is probably the problem. If it keeps running, the switch is definitely not. Then test the Wh/LB and R/LB wires at the ignition module for 12V. The one that has power is the problem circuit.

 

thanks... never thought to just unplug it.... just when you think you are working with a little common sense.... I'm a tad electrically challenged, though.... thanks for your advice, I know what you are describing and will check it out and report back...

I did notice that the wires white and red out of the ignition module switch poistions at the plug connector... in other words red goes to white and white goes to red.... although my 84 has the same condition

 

The color switch on the iginition module is correct. That threw me the first time I saw it also.

I would guess that you have feedback from some electrical circuit that is energizing the coil. With the engine off, turn the switch from off to on then off, and check to see if you have voltage on the + terminal on the coil. If you do, start pulling fuses to see where it is coming from.

If pulling the fuses doesn't work then disconnect the small wire on the starter solenoid and see if that circuit is the problem.

 

turns out my stop light circuit is somehow keeping my coil positive wire hot.... I unplugged the ignition wire harness while the truck was running and it still kept running...

I checked for voltage at the + coil terminal with the key in off position.... I had voltage... from there I started pulling fuses and checking voltage... got to the second fuse and voltage stopped....

some good old boys wired up the rear lights after sticking on a wood stake bed.... I suspect they tapped somewhere they shouldn't have... but for now.... pull the fuse, I can shut it off with the key.... put the fuse in while running and I have brake lights...... woo hoo, life is half good.....