Key turned off, ignition stays on and keeps running

[teamreno]

Hi,

I have an ‘82 FJ60 with the 2F engine. Everything is stock to my knowledge. I have an issue that recently developed where the vehicle will stay running when the key is turned into the off position. Along with the engine continuing to run, the gauges still have power to them as do the dash lights and accessories. I’m assuming it’s the ignition switch, but I wanted to check and see if anyone else has experienced this problem before.

Thanks!

 

[dogfishlake]

Hi,

I have an ‘82 FJ60 with the 2F engine. Everything is stock to my knowledge. I have an issue that recently developed where the vehicle will stay running when the key is turned into the off position. Along with the engine continuing to run, the gauges still have power to them as do the dash lights and accessories. I’m assuming it’s the ignition switch, but I wanted to check and see if anyone else has experienced this problem before.

Thanks!

That sure sounds like the right guess. Will the truck shut down after wiggling the key/switch? That would be your giveaway. Good luck.

 

[teamreno]

No the truck won’t shut down until I stall it. Even toggling back and forth between off and on wont get it to shut off.

If I stall it out to shut it down with the key in the off position it still has power to all the gauges and accessories. However if I disconnect and reconnect the battery, all gauges and accessories no longer have power. Almost as if it resets.

 

[micruz60]

Sounds like the switch, many cycles on/off will wear them out, try @RAGINGMATT, I believe he sells new ones.

 

[teamreno]

I tested the ignition switch per the FSM guidelines and it checks out ok. I thought it may be the relay but it appears that the relay is good too. And if it was getting stuck, it still wouldn’t explain the continued power to the gauges.

Looking to see if anyone else has any guesses on what it could be or systems to check. I’m stumped currently.

 

[teamreno]

Also what I find interesting is that once I disconnect the battery at the fusable links it appears to reset itself and no longer has the continued power to the gauges and ignition. Could the system be getting power from somewhere else? Looking over the wiring diagram I’m not seeing anything that’s jumping out at me for a source of power to the ignition, gauges, etc

 

[BlackCat]

I’d look into your tumbler as well. Can you pull the key out with it in the run position?

 

[teamreno]

Yes the tumbler is worn. After pulling the ignition switch and inspecting it, it does still actuate ignition switch.

 

[teamreno]

So I pulled the switch apart and the contacts look good. I’m still getting the correct continuity associated with each key position. Even turning the car off and unplugging the switch (breaking all continuity through it) the vehicle stays running and power is still running through the instrument cluster, brake warning light, etc. It must be getting back fed somehow is my only guess. I’ll have to look through the wiring diagram a little deeper.

There is a four prong female plug just forward of the relay panel that isn’t plugged into anything. Anyone know where this goes?

 

[teamreno]

Small update: after looking over the wiring diagram I’ve been trying to isolate the source of the problem. I was able to narrow it down to the circuit with the “Gauges” fuse in line. With the key in the off position I’m still getting 13.8v through the fuse at idle.

With that fuse removed, the vechile functions appropriately in regards to the position of he key in the ignition. It’ll fire up and run (without gauge function obviously) and shut off when the key is put in the off position.

I also saw that power to that fuse may be back fed through the “charge” fuse from the alternator if there is a problem with the diode that is in between them. If this diode wasn’t functioning properly or missing it could send power back through the charge fuse and into the “gauges” circuit and eventually the ignition relay. I put the gauges fuse back and verified that the problem came back. With the key in the off position and vehicle still running, I pulled the “charge” fuse to stop any power from being back fed into that circuit. However, the engine kept on running and the gauges were still fully functional. So I’m fairly certain the diode isn’t the source of the problem.

I replaced the “charge” fuse and pulled the “gauges” fuse and the problem went away again.

Finally put the “gauges” fuse back and now it’s functioning normally again?? The problem seems to have resolved for now.

I have a new ignition switch on order but it’s looking like that’s not likely the source of the problem. And looking at the wiring diagram I cannot for the life of me figure out where else power may be sneaking through to the “gauges” circuit. I also can’t figure out why the problem went away.

For now I’m just going to keep driving it until the problem resurfaces. If anyone had any ideas, im all ears.

 

[g-man]

total guess on my part but if the IG Main relay was bad and current was bleeding across from "w" to "y" wire it could back feed to the "gauge" fuse and then to the ignition. Looking at the schematic "d" gets supplied from the ignition switch so the gauge fuse shouldn't be charged unless the ignition switch is on. B on the other hand is powered from the fusible link so hot always.

 

[teamreno]

Ok yeah I wasn’t sure if it was possible to have bleed over like that but I’ll swap it out with a new one, they’re cheap enough anyways!

 

[g-man]

I'd be curious to know if your ignition relay is getting hot to the touch. Mine has been hot for a long time but still works.

 

[teamreno]

So it’s not really getting hot, but I imagine if I let it run longer it might.

I did find this interesting, however. The other day with the key in the off position and the engine stuck running I pulled the relay to try and get the truck to turn off. With the ignition relay removed, it still continued to run! Maybe there’s a short in the wiring/connector? I’m not going to get a chance to work on it while I’m at work the next couple days, but I’ll investigate more this coming weekend.

 

[g-man]

when you pull the ig main relay see if the "engine" fuse loses power? It should, per the 84 chassis and body fsm schematic. Engine fuse powers the fuel cut solenoid and would kill the truck at low idle. this for a 84 and up 2f. Not sure about an 82.

 

[Randy88FJ62]

Staring at the wiring schematic for 30 mins, if you pull the ignition relay and it's still running then I am thinking the ignition switch is still connecting IG or ST2 position to the coil / distributor. I'm going to guess ignition switch.

In post #5 you said you checked the ignition switch per FSM. Are you 100% sure?

You did this check?

 

[Randy88FJ62]

For kicks I looked at the FJ62 manual for the 3FE motor and found this:

 

[Randy88FJ62]

Not sure if engine 'dieseling' counts as continued running. Anyone confirm or comment?

 

[teamreno]

Yeah I did check continuity for different positions of the ignition and everything came back ok. But I have a new switch coming in the mail so I’ll replace it anyways just to check that off the list of potential culprits.

I don’t believe the engine is dieseling, but I will recheck timing. As I said the problem has gone away for now...but according the the prior owner it has happened before. So I’m sure it’ll come back.

 

[teamreno]

However if it were dieseling, how would that cause the gauges circuit to stay energized?