FJ40 won't start, except when it does

[Rob]

Need some help from some of you knowledgeable folks. Sometimes the FJ40 starts; sometimes it doesn't.

Last week, I ran to Safeway a half-mile from the house in the FJ40. Came out and it wouldn't start. Turned key; nothing. Wife brought jumper cables. It started, and I was able to get it home. (I'm guessing now that the jump didn't actually matter.)

A few days later, I went out and cranked it up with no problems. Shut it down, tried again. Nothing. Later, it started up again.

Today, I went out and got nothing again. Hit the battery with a mutimeter. Reading was 12.54. Tried to jump it with the FJ Cruiser. Still nothing. Checked out every connection under the hood that I recognized and fiddled with wires. Tried it one more time. Cranked right up.

When it won't start, I noticed the beep that tells me my seatbelt is off works, but the horn, fan and wipers don't work.

The questions are:
1) What the heck is going on?
2) How do I isolate what the heck is going on?
3) If can isolate what the heck is going, can I fix it myself?

Thanks in advance for any advice, help, brainstorming or even commiseration.

[Jim]

Sounds like me Sunday night at 11:30PM leaving my brother's house - hit the key and "click" but no starter spin. Headlights on - click - no headlight dim. Pull out a heavy chunk of metal and tap the starter solenoid a couple times - bingo!

Could your starter solenoid not be engaging to activate the starter? Is it 'easy to whack' next time it should happen?

[Tom]

Did you check the negative cable where it attaches to the frame and starter for corrosion? I'm no expert but I'm thinking bad ground.

[Brad]

Possible bad grounds or ignition switch.

[4Runninfun]

I would check your main ground coming off the battery. Then what I would do is when it won't crank over have your wife hold the key over and smack the starter your solenoid may be sticking. I would start here and let us know what you come up with.

[Rob]

Excellent advice. I'll try both of those things.

[Patrolman]

I agree with everyone. One thing not mentioned, even if the cables have a good ground connection, the could be corroded on the inside.

Keep in mind even a nearly dead battery will read 12v, but won't put out enough amps to crank the engine. Imagine 8 AAA batteries, they will read 12v when in series, but there is no way they would turn the engine.

[Chris]

Rob previously posted:

[Rob]

Patrolman previously posted:

[Rob]

Chris previously posted:

[Brad]

As they are generally cheap insurance, always better to replace.

[Jim]

Should it happen again - have jumper cables ready (no need for a second battery). Use the jumper cables to "jump" your battery negative terminal to bare/block ground. Does the issue remain? Jumping battery positive to the next "large" termination of the positive cable is an option too.

Essentially, with jumper cables you're "temporarily replacing" the questionable wiring with known good wiring.

[Patrolman]

That is a good idea! Never thought of that.

[Rob]

Good idea, Jim. I have cables in the back of the 40. Thanks.

[Jackie]

I would think that.........

........Oh wait... you asked for "knowledgeable folks" advise.

never mind! Hope you get it figured out!

[Hypoid]

Rob previously posted:

[Rob]

I do have the diagram. If it isn't the ground, I'll check that next.

[Robert B]

minus the other things not working my truck did the exact same thing with the some times starts fine sometimes nothing happens when the starter was bad........it took autozone 3 times to test to find it was bad because if u held it just right before testing it would run fine but it u held it another way then it was dead as a doornail..........probably same idea if i would have hit it with a hammer .......wiring could explain why ur other items also didnt work some times but i am not sure how it was routed in your truck but if you can afford a new starter and its cheap like mine was i i would try that just cause

[Robert B]

or as mike did say 2 posts above this something in the column could be wrong or broken

[Hypoid]

I have experienced similar problems from the switch; they do wear out.