Ignition switch bad?

[mountainman]

I went out to start the 74 FJ40,turned the key,and it started right up. As soon as I let go of the key,it shuts off.I was driving it earlier,and it was fine. If I hold the key in the start postion,it stays running. Sound like a bad switch? Thanks.

 

[Bret]

Check your fuses?

 

[mountainman]

Yep,just went out and checked. That's what it was!! Forgot all about that. Thanks for the help!!

 

[Pin_Head]

Fuses? The igniiton coil and starter are some of the few circuits that are not fused. Is your wiring non stock? Usually it means a bad switch or a bad ballast resistor.

 

[mountainman]

I have a 79 dist. with the ignitor system. I checked the fuse block and found the one for the ignition (7th one down) was blown. I replaced it,and it fired right up.
I thought it was the switch,with the way it was acting.

 

[Pin_Head]

There is an "engine" fuse, but this is for engine accessories, like the voltage regulator and emission computer. The ignition is not fused at least up through 1981. Replacing the fuse is probably coincidental with it working again, unless someone wired your ignition through this fuse, which is not stock (or desirable).

 

[mountainman]

There has been a lot of rewiring by the looks of things under the hood.I better check things out so this doesn't become a problem. Thanks Pin_Head!!!

 

[Bret]

When mine did that I replaced the fuse and it's worked since. If you want to make sure take the fuse back out and see if the symptom returns. According to Haynes the coil gets power from the IG wire leaving the switch before the "engine" fuse, but I don't know if that is correct or not. If it actually gets it power after the fuse when you switch to start then you could feed power back the line for the emission box. If you have a meter you can check it easy enough. Hope it keeps working...

 

[mountainman]

I just went out and pulled the fuse,and it wouldn't start. Same as before. You keep the key in the start position,it stays running.When it came back to the on position,it shut off. Put the fuse back in,and started right up. I'll put a meter on it tomorrow. Thanks again.

 

[Pin_Head]

It just means that someone rewired it by hooking the ignition coil to the engine fuse. This may run OK, but there are already a bunch of theings running off the engine fuse, so maybe addition the coil overworks it so the fuse blows. Toyota evidently thought that it was better and safer not to fuse the ignition so that the engine won't shut off if there is a small short.

 

[bkfj40]

doesn't the idle solenoid power go through the fused circuit? I'm thinking it does and that is why it shuts off once you have the key in the "run" position....

bk

 

[mountainman]

It just means that someone rewired it by hooking the ignition coil to the engine fuse. This may run OK, but there are already a bunch of theings running off the engine fuse, so maybe addition the coil overworks it so the fuse blows. Toyota evidently thought that it was better and safer not to fuse the ignition so that the engine won't shut off if there is a small short.

I'm gonna put the meter on it tomorrow,and see what going on.

 

[mountainman]

doesn't the idle solenoid power go through the fused circuit? I'm thinking it does and that is why it shuts off once you have the key in the "run" position....

bk

You're right. I didn't hear the 'click' when I turned the key on. With the new fuse,it was back.

 

[okie]

I went out to start the 74 FJ40,turned the key,and it started right up. As soon as I let go of the key,it shuts off.I was driving it earlier,and it was fine. If I hold the key in the start postion,it stays running. Sound like a bad switch? Thanks.

hey u wanna know something even weirder?

my truck works so when you turn the key and get nothing but the starter clicking and let go of the key there is a 10 second pause and then she starts up on her own! lol