'05 intermittent won't crank - start

[axxense]

Thanks for the help. It hasn't cranked for 2 days now.

Tapping the starter didn't help. I wonder exactly how to jump (arc/cross) the starter to see if it is dead. I was also hoping there would be some easy voltmeter check I could do while turning the key to 'start' to see if is the switch - something to keep me from replacing a component at a time only to have murphy toy with me - not discovering the prob - or worse - thinking I have fixed it cuz it cranks its random crank after I swap something out.

I have already spent more time reading the gazillions of posts than what it would take to swap out the engine

I suppose I will replace the ignition switch first and see what happens. That seems the least time and $ consuming of all of the options. I will give an update post after doing that.

I just dread replacing the ignition switch, then the starter, then the battery, then the neutral sensing switch, only to discover it was the last option that fixes it or to discover I still have some whacked out problem.

Thanks again.

[Rene S. Nielsen]

Hi

You could try to set the ignition switc to the normal running position and then hot wire the starter.

Best done from behind the right front wheel.

Get a screwdriver and hotwire the small therminal in the middel to one of the big ones. If you choose the wrong big one nothing will happen.

If you have tried both and still nothing then you have a starter problem.

If it cranks but won't start then the problem is not the starter and posible not the ignition switch.

Hope this helps, and if I'm mistaken please to correct me

Regards
Rene

[axxense]

Hi Rene,

Ok - Long-winded post coming...

Here is what I am deducing from your post...

...I am concluding that the smaller terminal is to the solenoid that pushes the starter in. In turn, the top-most larger terminal is what turns the gear and the bottom-most large terminal is the battery lead (power).

Here is what happened...

(with ignition switch in the 'run' position)

...jumped the smaller terminal to the top-most large terminal and got nothing (kind of figured such, as the bottom-most large terminal is the hot).

Jumped the smaller terminal to the bottom-most large (hot) terminal and got a little blue spark, but, no reaction.

This, now, confirms your post suggestion as being a starter problem.

I then jumped the two larger terminals (the top-most large and bottom-most (hot) large terminals), and the sarter spun (but, wasn't engaged, so, it didn't crank).

Soooooooooooooooooooo, the ultimate conclusion is, when I turn the the ignition switch, which I now believe is fine, all the way to 'start', the solenoid is not engaging, which, in turn, does not then power-up and engage, nor spin, the gear, which renders the no crank situation.

Lo, it appears you have helped me isolate the problem to my starter, and, more specifically, the solenoid.

I will pick up a new starter and install it and let you know how things turn out. Likely I won't have the time to do so until this weekend.

Does this all sound on the mark to you or you other guru-types?

It does bring up a question, however... ...why would power be going to the bottom-most large (hot) terminal when the key is in the 'run' position? I might guess (incorrectly, it appears ) that it would only have power when the key is turned all the way to the 'start' position - power goes to the bottom-most (hot) terminal, the solenoid then pops in, thus powering up and spinning the gear, cranking and starting the engine, the key is then let to return to the 'run' position, removing power from the bottom-most (hot) terminal, thus allowing the solenoid to return, thus removing power from the gear, stopping it from spinning. Does anyone feel like explaining this to me?

THANKS! I'll let you know how the starter replacement goes this weekend and likely bestow more thanks upon you!

[Rene S. Nielsen]

Hmm

If I remember correctly then I have 3 terminals on my starter

1 (big) goes directly to the batery positive.
2 (big) goes to ground (I thought) maybe it's just the other side of the solenoid.
3 (small) goes to ignition.

I jumped the 1 and the 3 in the above text and it started up no problem.

So I replaced the ignition key and that fixed the problem.

Just trying to help without you having to buy to many spare parts.

I would have thought that when the starter started to spin the it would automatically engage so your probably right that it's the starter.


Rene

[HUMTECH]

Get someone to hold the key in the crank position and check the small terminal on the starter with a testlight, if it lights you need a starter. You can also use a jumper wire at the starter relay, remove the relay and jump across terminal 30 and 87 if i remember correctly, this removes the ign switch from the circuit, if the starter cranks then it could be the ign switch.

[axxense]

Rene - you are, at least, pretty much, if not totally, correct - the smaller terminal is the 'start' (ignition) terminal. The bottom-most large terminal is power (hot). The other large terminal goes back in through the side of the cylinder body of the starter.

That still tells me when I jump the hot to the 'start' (smaller, ignition) terminal - I should get crank if all was fine with the starter.

I am, though, a little mystified by the starter gear spinning, but no engagement, when I jump the large hot terminal to the other large terminal. Wouldn't mind a bit if someone clued me in to that one.

I removed the starter relay and jumped 30 and 87, as you said, HUMTECH, and got nothing (well, maybe a teenie spark when I poked the lead in) - no crank, no spin, nada.

I also did something like HUMTECHs test light check... ...using a voltmeter, I clipped the red (+) voltmeter lead on to the smaller start (ignition) terminal. I then clipped the black (-) voltmeter lead on to the starter housing (ground). I then placed the voltmeter on the hood of the truck (so I could see it from the drivers seat - my voltmeter has way long leads) and turned the ignition all the way to start - the voltmeter read voltage (12ish volts).

This told me two things - the starter wasn't engaging and the ignition switch was working. If it read little to nothing, I may have thought an ignition problem - a bad ignition switch or something in the ignition circuit (likely, with a HUMMER, the ignition switch, as explained in other posts).

I think this single test is the easiest and most comprehensive - it will tell you almost definitively - A) You have a starter problem (if the voltmeter reads 12v+/- and the starter doesn't crank), or, B) You have an ignition switch (or something in the circuit) problem (if the voltmeter reads little to nothing). To do it, though, you will need a voltmeter that has about 3' leads (or longer!) or someone else to turn the key for you.

I don't think I can isolate it any further.

Again, I will replace the starter this weekend and post what I believe will be the final post to this thread.

Many, many, thanks to all. I believe I have totally nailed it down to the starter and haven't spent a dime. Sure, my time is worth something, yet, all I missed was some TV and gained a TON of knowledge. Maybe I can now help others, in the future.

[axxense]

You guys are AWESOME!!! Rene, HUMTECH, EVERYONE!!!

Replaced the starter tonight and all is fine - fired right up.

Thank you sooooooooooooooooooooo much. Your help was indispensable. VERY much appreciated!!!