Engine running when I turn the key off (1 Viewer)

[mshelby]

Last night my truck wouldn't start, checked and the ignition fuse was blown. Replaced it with another 7.5A fuse and it cranked fine, however now when I go to turn it off the engine still runs...I can rev it up but can't put it in D because the key is removed.

Everything else is off, radio, cb, ect. but the engine just still runs until I turn the key to start and it kills it.

Is this a bad ignition?

 

[Tools R Us]

One possible culprit is starter contacts sticking, is the starter running with the motor? If so don't rev the motor, run it only enough to diagnose. Loosen a battery cable, run the motor briefly, listen for the starter running, remove the cable to kill. If this is the problem, there is risk in running the motor, if the starter comes apart, it can cause a direct to battery short, possible fire, so be ready to pull a battery cable.

 

[mshelby]

The starter doesn't run with the engine. I just made a 50+ mile trip this morning and there was no problems other than the stated issue.

The only way I have been able to kill it was pull the battery or turn the key and as soon as the starter clicks let go which I know is not safe.

 

[Tools R Us]

The starter doesn't run with the engine. ...

Good deal, then it's most likely safe to run/test. Sounds like you have a back feed somewhere, most commonly in the EFI/fuel pump, alternator, etc circuits. I don't have much experience with the 3FE, so maybe someone who does will chime in?

Other than the fuse, has anything unusual happened or other recent repairs/mods?

 

[tirewater]

Sounds like an issue with the ignition switch.

Do you have an aftermarket alarm w/ remote start wired in? Or any non stock wiring?

 

[mshelby]

Good deal, then it's most likely safe to run/test. Sounds like you have a back feed somewhere, most commonly in the EFI/fuel pump, alternator, etc circuits. I don't have much experience with the 3FE, so maybe someone who does will chime in?

Other than the fuse, has anything unusual happened or other recent repairs/mods?

I did replace the alternator a little over a month ago but it's been running without incident, other than that just replaced the radiator but that wouldn't cause this.

Sounds like an issue with the ignition switch.

Do you have an aftermarket alarm w/ remote start wired in? Or any non stock wiring?

It looks like the PO had an alarm installed, I have had it since November and haven't had any issues with it and it looks like it was removed cleanly by a professional.

 

[mshelby]

Went and removed the ALT cable/plug and put them back just to make sure that wasn't a problem, cranked the truck and this time when it wouldn't die I pulled the neg battery terminal and it still ran...removed the positive too and same thing so I wound up having to disconnect the alternator while it was running just to stop the truck.

 

[bwr9300]

Fxxx hit your alternator on the back with a hammer a couple times. That's what fixed mine. (if its problems with your alternator, insides not being seated right that is. Obviously if it is your alternator, your situation is different than mine. But, again if it is your alternator might as well try a quick fix.)

 

[mshelby]

Fxxx hit your alternator on the back with a hammer a couple times. That's what fixed mine. (if its problems with your alternator, insides not being seated right that is. Obviously if it is your alternator, your situation is different than mine. But, again if it is your alternator might as well try a quick fix.)

That's your new answer for everything isn't it? lol

"Your woman giving you s***? Hit her on the back with a hammer a couple of times."

 

[Tools R Us]

... I wound up having to disconnect the alternator while it was running just to stop the truck.

The big charge wire or the plug in connector? If the alternator exciter circuit fails it can feed back to ignition, depending on how the circuit is wired, I don't have a diagram fir the 3FE. If it runs normally (other than not charging) with the plug in alternator connector removed, it's a strong indication that the regulator in the alternator is bad.

 

[bwr9300]

That's your new answer for everything isn't it? lol

"Your woman giving you ****? Hit her on the back with a hammer a couple of times."

haha funny you say that.. buddy of mine was just over and I was showing him how I learned (from MUD) to knock the alternator on the back w a hammer... he used to wheel a 91 toyota pickup and telling me how he used to do that to his starter anytime it'd act up for a long time.... so that answers your question... its my answer to anything(person) it works on

 

[mshelby]

The big charge wire or the plug in connector? If the alternator exciter circuit fails it can feed back to ignition, depending on how the circuit is wired, I don't have a diagram fir the 3FE. If it runs normally (other than not charging) with the plug in alternator connector removed, it's a strong indication that the regulator in the alternator is bad.

I pulled the 3 wires and the charge wire, now I have learned that pulling the "charging" fuse will also kill it so I am thinking that may have something to do with the regulator in the alternator.

The problem I have is the PO cut the alternator plug harness and has crimp terminals to connect the wires individually, when I replaced the alt I just marked which went where but they could have been wrong initially.

haha funny you say that.. buddy of mine was just over and I was showing him how I learned (from MUD) to knock the alternator on the back w a hammer... he used to wheel a 91 toyota pickup and telling me how he used to do that to his starter anytime it'd act up for a long time.... so that answers your question... its my answer to anything(person) it works on

I used to beat the starter of my 75 Impala, on cold mornings it wouldn't want to turn over without showing it who's boss first.

 

[landtank]

That's your new answer for everything isn't it? lol

My first thought when he posted it. Kind of like when you discover duct tape!

 

[mshelby]

My first thought when he posted it. Kind of like when you discover duct tape!

If I can't figure out this problem I may just wrap my truck in duct tape and beat it with a hammer.

 

[bwr9300]

went wheeling in lots of mud and water today. as I began to drive home little old battery light showed it's face. I pulled over and started banging on the back of the alternator with that wheel-nut tool (no hammer in rig, at least then). Sure enough, battery light went off and alternator started charging its little heart out again!!

I'm telling you, Matt. Try it. wouldn't surprise me if your rig starts to act normal again!

 

[mshelby]

haha I am going to look at all the logical steps tomorrow (looking for a wiring diagram, double checking all fuses, tracing for shorts) before I break out the hammer but trust me it's in my tool bag and it keeps saying "pick me pick me"

 

[bwr9300]

that made me laugh... its funny, tonight when I've been starting my rig I find myself trying to convince myself its taking too long and a small part of me hopes it won't turn over, so I can get in there and bang the starter with a hammer or whatever metal tool I have access to.

I hope you figure out the problem, man. But hey, at least it's starting huh

 

[TrickyT]

Disconnect the alternator (unplug the connector and disconnect the wire on the stud), then start the engine and see if it still misbehaves. If it does, then the problem is not the alternator.

The other potential cause is a short in your wiring or a defective ignition switch so that 12v is fed to the ignition circuit even when the key is off. You can troubleshoot this with a voltmeter and wiring diagram while the engine is off.

 

[mshelby]

After disconnecting the alt all together it turned off fine so it was either the alt or the wiring. I hooked up just the charging cable and it still turned off fine.

Through the process of elimination I believe the PO mis-wired the 3 additional wires out the back, I changed the order of which wire went where and right now it's working fine.

If anyone has a wiring diagram of those wires I would appreciate posting it, I want to make sure they are all correct and no future issues arise.

Thanks for the idea TrickyT, it slipped my mind to try it without the alt hooked up at all.

So another issue resolved with no hammer or duct tape needed