Stumped. My 2F won't turn off

[fyton2v]

Well, I've searched and searched. On my '78 FJ40 the engine starts fine, runs fine (sort of), but won't turn off when the ignition moves out of "On" to the Accessory position. When you turn the key to Off, it shuts off, which is nice. When searching on this topic I'm finding info on alternator issues, diodes, and trucks that continue to run when the key is out of the ignition. My truck shuts off fine, just not from the accessory position.

I reinstalled my original harness a few years back, then the truck sat for some time, and now I'm back at it. The harness was/is in pretty good shape. I've checked ground connections and the rest of my electrical system appears to be working fine. Oh wait, my hazard switch wasn't working today, but not sure that's related.

Any tips on where to start troubleshooting? Poking at my electrical system like a monkey hasn't worked thus far.

Thanks...

 

[thebigredrocker]

It has to be something simple.

Here's a link to Coolerman's 78 .pdf http://www.globalsoftware-inc.com/c...ics/FJ40/1978FJ40/1978fj40_wiring_diagram.pdf

 

[65swb45]

If the ignition switch is old, the contacts inside the switch could have worn an arc of metal shavings allowing current to travel.

I just changed out a customer's switch which made a starter click noise from accesory position (even scarier). New switch, no noise.

Hth

Mark

www.marksoffroad.net

 

[edwjmcgrath]

It sounds like a bad switch to me too. If it were me, I'd just order one and put it in before looking into anything else. New switch is cheap and a simple fix and it probably should be replaced anyway after 38 years.

 

[fyton2v]

Thanks all. And the wiring diagram is really useful. I'll try and replace the switch and see if that does the trick.

 

[fyton2v]

Well, replaced the ignition switch with a new OEM unit today and no joy. If it's not the switch, I'm out of ideas. It is likely something pretty simple and I'd appreciate thoughts on where to start looking next. Could cross wiring the ignition coil or starter cause this. Pretty sure I put my wiring back the way I found it, but who knows.

 

[sggoat]

Same issue with a 71 I was helping with. Check the wiring from the ig to the dizzy--the dizzy may have a wire that is "hot" all the time(Doesn't even go through the IG) Try this-start the truck and pull one of the battery cables off(don't care which)--if it stops, this could be the prob.

 

[rkymtnflyfisher]

It has to be getting voltage while it is in ACC that it should not be getting, grab your meter and start working it backwards. There should be 2 distinctive circuits, run and acc.


Disclaimer-I have been drinking and running a grinder all night, I may have metal dust in places it should not be causing me to be full of crap..........

 

[sggoat]

It has to be getting voltage while it is in ACC that it should not be getting, grab your meter and start working it backwards. There should be 2 distinctive circuits, run and acc.


Disclaimer-I have been drinking and running a grinder all night, I may have metal dust in places it should not be causing me to be full of crap..........

You don't have enough metal dust just yet-cause you are right-----

 

[fyton2v]

Going to start tracing and testing voltage today. Hope it's not a short in the harness under the dash. Such a pain to get in there. Tnx.

 

[Captn Conch]

Yes that was my '71 sggoat was referring to, He said first off what did you mess with? I told him I did rewire the hot wire directly from the battery to the battery terminal on my HEI. but I was sure that wasn't it..It was it. So if you redid some harness work follow sggoats directions.

 

[Spike Strip]

Well, replaced the ignition switch with a new OEM unit today and no joy. If it's not the switch, I'm out of ideas. It is likely something pretty simple and I'd appreciate thoughts on where to start looking next. Could cross wiring the ignition coil or starter cause this. Pretty sure I put my wiring back the way I found it, but who knows.

Have to ask the obvious here, but you replaced the electrical switch or the Lock/Tumbler ?

 

[rkymtnflyfisher]

Well, replaced the ignition switch with a new OEM unit today and no joy. If it's not the switch, I'm out of ideas. It is likely something pretty simple and I'd appreciate thoughts on where to start looking next. Could cross wiring the ignition coil or starter cause this. Pretty sure I put my wiring back the way I found it, but who knows.

@Spike Strip , I think he has tackled that one already, look like there is a wire placed in the wrong location somewhere. That would be my guess at least.

 

[Spike Strip]

Many people confuse the ignition electrical switch and the ignition key/lock mechanism when asked if they've checked the ignition switch because they've never had a steering column apart. Happens frequently in the 60-section

Yeah, the OP has prolly got it, but you never know, so just asking to help avoid those moments.

Don't wanna hear nothin' about the 40-section having smarter peeps.

 

[fyton2v]

It replaced the switch, not the lock cylinder. So I have a dumb question. When the ignition is in the acc position should I be seeing about 11+ volts at both the coil and the ignition side of the starter?

 

[fyton2v]

Oh. And the ignition coil/resistor gets pretty warm by just being in the acc position. That doesn't seem normal, but what do I know?

If my guesses are even close to being right (probably not) is there a switch or something between the ignition switch and the starter that could be involved? When I was reassembling a few years back I don't recall anything that could short the ON circuit with the ACC circuit. I've checked the fuse box and it's in good shape too. Found a blown fuse that was keeping the hazards from working. Tnx.

 

[thebigredrocker]

If you don't figure it out, perhaps post some good photo's for the crew here to look at. Coil, starter and alternator might cause someone to chime in.

 

[tlc762]

In the acc position you should not have power to the ignition system- the + side of coil, there should only be power there in the on and start position. It is supplying power to the ignition in the acc position which it why it keeps running... Check your wiring...
HTH
Will

 

[rkymtnflyfisher]

Did you have any luck last night with this?

 

[fyton2v]

OMG no. I scrubbed all the harness and connections that I could actually see and touch without yanking out all the items that bolt-up under the dash, like the heater and pedal bucket, etc. Yesterday, I was also installing a SOR liner for the cap, and that took way longer than I expected.

I don't think I'll have time to really dig into it today. But i'll end up attacking this week and post up what I find, or let everyone know I gave up.

Did you have any luck last night with this?