Starter keeps cranking

Put a GM starter on. Also replaced the starter switch (under steering colunm) to the tune of 161 dollars. Same problem. Don’t know what else to do. Help!

might take a bit more diagnosing then, I haven't heard of this happening before except since about 04+ gm added a feature to keep the starter going for a couple seconds after you release the key to be sure it fully starts (under specific conditions) such as when it is very cold out and cold start. I would speculate maybe something is giving erroneous information like a temp sensor or iat, etc.
no check engine light for anything?

black1970 said:

No, when you release the key the starter keeps turning until the engine starts or you turn the key to the off position.

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can you clarify this? cause if I'm reading it right you turn the key to request cranking, the engine itself doesn't start ****** but the start keeps trying until you turn the key to off.

mine isn't the same so don't know forsure, others will have to answer but isn't that how the Gen 4 engine works? it's basically a starter button but turning the key. Gen 3 being the last of the key to crank directly? I think I read that somewhere years ago in a ls swap article

I'm just wondering if you have other issues causing engine not to fire up. so the bcm that runs the start up keeps cranking away. if so usually they stop after a bit to keep form over heating the starter. something like 30 sec or so?

You will need a scanner to read what RPM the engine is reading during the Starting Process...
If the ecm doesn't think the rpm's are high enough to go from crank to run, it may be
keeping the starter engaged.
I don't know the exact spec, but usually it around 400 rpm crank speed.
Maybe your crank sensor is being "lazy"

Foggy said:

Maybe your crank sensor is being "lazy"

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I’ve been telling my wife this for years.

I know this post is real old, but I'm having the exact same problem and can't figure it out. OP, if you see this please post your solution. I wish everyone would follow up with the solutions, that would make these forums even more helpful.

big_g1 said:

I know this post is real old, but I'm having the exact same problem and can't figure it out. OP, if you see this please post your solution. I wish everyone would follow up with the solutions, that would make these forums even more helpful.

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is there a starter relay on these trucks? might be hanging up?
the other thing you might try if you can even get to it, is run a test lead from the starter trigger wire up to a test light, so you can watch what the body control module is doing. if the light goes out and the starter is still dragging, you know it's mechanical. if the light stays lit, you will know it's electrical and then trouble shoot from there?

big_g1 said:

I know this post is real old, but I'm having the exact same problem and can't figure it out. OP, if you see this please post your solution. I wish everyone would follow up with the solutions, that would make these forums even more helpful.

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Lol it's not that old at least you didn't resurect a 15 year old thread.
as noted already try swapping the starter relay for beginers

big_g1 said:

I know this post is real old, but I'm having the exact same problem and can't figure it out. OP, if you see this please post your solution. I wish everyone would follow up with the solutions, that would make these forums even more helpful.

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The OP hasn't been on here since July last year.

It would help for us to know what you're driving. Put it -- year, make, model -- in your signature so it's always there.