98 K1500 motor swap but no start

Good logic - I’ll pull both the starter and battery and do some testing to make sure the battery is good, not just new, and the starter responds as it should. I’m praying the starter is shot - that seems to be the easiest solution at this point in the process.

Have an excellent Father’s Day! My wife asked what I’d like to do to celebrate it and I didn’t have the heart to say “work on my truck”! She doesn’t yet understand the therapeutic nature of the process - but she indulges me nonetheless! Maybe a little tinkering in between flipping burgers on the grill

DHud said:

Have an excellent Father’s Day! My wife asked what I’d like to do to celebrate it and I didn’t have the heart to say “work on my truck”! She doesn’t yet understand the therapeutic nature of the process - but she indulges me nonetheless! Maybe a little tinkering in between flipping burgers on the grill

Click to expand...

Boy I get it -- your dad is looking down and is proud of your answer. :0)
As dads, we have so many hats to wear, and it's tough wearing them all at the same time.

Enjoy your good fortune. Your fellow GMT400 members are patiently waiting for a status update - no hurries, no worries,
enjoy your family today. Fortunately, the truck won't fix itself, so the problem will still be waiting for
you once Father's Day is over. :0)

Fun stuff!

PS - Although the attached photos of my oldest grandson is stretching the definition of Father's Day
a wee bit, the way I see it my daughters have seen fit to give me a fresh team to further enjoy
the old truck hobby with. I am so busy counting my blessings on this Father's Day.

I had a little time to work on the truck during the little guys’ nap time!

Update:
Pulled the starter and did a bench test myself - got it to engage with no problems using jumper cables and a battery. (Bummer - I was hoping this would be the obvious problem) Reinstalled the starter and tried jumping over the switch in the same way that I bench tested it. (I know, a little redneck, but I’m getting slightly impatient). Jumping it with a screwdriver while the ignition is in the off position (and again with key in run position) resulted in same “Ping - dead” effect. I had my son quickly disconnect and reconnect the battery after everything went dead and that brought the power back on right away. While I was laying under the truck with my redneck screwdriver, I noticed that it sure seemed like the “Ping” sound was coming from the starter.
Can a starter engage with no load and falter like this when put under load? Will a parts store do more extensive testing on a starter to reveal something deeper? I still need to take the battery in to get it load tested…
The saga continues! Thanks guys!

DHud said:

Update:
Pulled the starter and did a bench test myself - got it to engage with no problems using jumper cables and a battery. (Bummer - I was hoping this would be the obvious problem)

Click to expand...

Alright. I like the fact that you are willing to test vs just throwing a new starter at it.

OK, the key to understanding what we're observing is keeping track of the variables.

1) Using the jumper cables instead of your truck's power cables is a variable.
2) Was the battery you used the same exact one in the truck, or just another 12v battery in your shop?

But you were able to get this starter to operate while out of the truck, but not in the truck, on an engine with
the plugs out & can be turned over by hand? Hmmm...

DHud said:

Reinstalled the starter and tried jumping over the switch in the same way that I bench tested it. (I know, a little redneck, but I’m getting slightly impatient). Jumping it with a screwdriver while the ignition is in the off position (and again with key in run position) resulted in same “Ping - dead” effect. I had my son quickly disconnect and reconnect the battery after everything went dead and that brought the power back on right away.

Click to expand...

You know, I absolutely believe you when you share these observations, but the problem I'm having is that
*I* currently can't explain this behavior using just the wiring circuitry documented in the Factory Service Manual?

Q: At this point I'm wondering if there is some remnant of an aftermarket anti-theft device still connected to
your truck? Adding an anti-theft device to these trucks was a pretty popular thing to do back in the day?
(I've been trying to reason through how the headlights are being shut off after an attempted cranking, and not
being able to explain to my satisfaction how these symptoms are occurring?)

DHud said:

While I was laying under the truck with my redneck screwdriver, I noticed that it sure seemed like the “Ping” sound was coming from the starter.
Can a starter engage with no load and falter like this when put under load? Will a parts store do more extensive testing on a starter to reveal something deeper? I still need to take the battery in to get it load tested…
The saga continues! Thanks guys!

Click to expand...

Now that we know that your starter has demonstrated the capability to operate, I'd like to stop
here and explain getting a starter to spin is actually a discrete 2-step process. (Normally I don't
drag folks through this, but since it sounds like your starter is getting stuck inbetween these
2 steps I'd like to discuss this further.)

OK, having the electrical wiring diagram that we used earlier to analyze the starter relay may be
helpful.

Step #1: We turn the key to start, and power is fed from a 40A fuse, through the starter relay,
and to the starter solenoid. Thanks to all the windings in the solenoid acting as an electromagnet when
current is applied, the center plunger inside the solenoid is pulled towards the power cables we've
connected to the starter. (ie: Towards the front of the truck.)

At the end of it's travel is a high current connector...and when that connector hits the contacts,
the big current from the 2 gauge positive cable is going to be coupled directly to the
starter *motor*. Spinning will immediately commence.**

Meanwhile, thanks to a pivot, this plunger hurtling towards the power cables is going to throw the
starter's pinion gear in the opposite direction towards the flywheel. Study this photo and see if you can
visualize all this movement:


(credit: '67-'72 chevytrucks.com -- How our starters work)

Now here is an important detail. We need to fully mesh the starter pinion
with the flywheel/flexplate's ring gear before it starts spinning, or else
we are going to chew up the teeth in short order. So what this design
does is first throw the non-spinning starter gear hard and fast into a fully
meshed position with the flywheel, and up to this point ALL of the work has
been accomplished by the smaller purple wire. This is key.

Step #2: Now when you got the starter to operate, what happened is once the
starter solenoid plunger got everything fully extended, the "heavy duty"
contacts are firmly connected. And since those jumper cables gave you
the full current when you tested it on your bench, the starter started
spinning. (Instead of Ping > quiet, we get Ping > Spinning)

THIS is where we're coming up short in your truck. The Ping is the sound
of the solenoid throw, but the lack of rotation from the starter *motor* is
the deafening silence afterwards.

I don't know if your truck's battery has the inability to deliver the
necessary current, or your battery is OK, but either the high current
ground or power cable has excessive internal resistance. (Due to corrosion,
or broken individual wires, or some combination of the 2?)

NOTE: If you 'starve' the starter solenoid for current due to a marginal path,
as a troubleshooter I could make the argument that the lack of current doesn't
allow the starter solenoid to fully extend all these moving bits against the return
spring? And since the "heavy duty" contacts are never closed, the starter motor
never gets the power needed for spinning. But thanks to your latest 'in truck'
troubleshooting via the screwdriver method...and this didn't change the behavior,
so the problem is not the wiring from the starter relay? (!)

****

But this same trick worked on the bench! Thanks to your troubleshooting
efforts, I think we're on the cusp of figuring this out.

1) Your starter worked on your bench. If did NOT work either before or
after in the truck.

2) Using the jumper cables that worked on the bench, can you temporarily substitute
these into your truck? One jumper cable supplying the ground to the block,
the other cable supplying the 12v to the starter motor instead of the 2 gauge cable?

Let's say that the jumper cables get the starter to work in the truck. One at a time,
disconnect the positive jumper and see if it still works? If it doesn't, Voila! it's a
bad starter power cable. If it still works, then disconnect the negative jumper cable
and retest.

****

And what if the jumper cables don't change the behavior? Then if you used a different
battery on the bench check, we have narrowed it down to something goofy in the
truck's battery. And now it's time to take this battery somewhere for a definitive
load test.

****

I apologize for the length of this reply, but this is the level we have to think when
your starter works on the bench, but it won't work on the truck. Assuming that
you have a good battery, + good positive & negative 2 gauge cables, and a
good starter, then your minimalist screwdriver test *has to work*, whether in
the truck or on the bench. (!)

It's just a matter of figuring out which variable is the one that's the root cause of your "Ping, no crank" scenario.

I am looking forward to your next update. Hope this helped explain why bench good, truck bad.

Happy hunting --

**(Optional viewing)

This YouTube video gives a good demo of what all this physical movement looks like
thanks to them cutting viewports into a working starter. If you skip to the ~19:55 spot
in the video you can get right to the good stuff: (Starter Operation Demo)

That's good stuff, @Road Trip - thanks for the deep dive into the starter mechanics. I appreciate understanding how things work bcs it helps to troubleshoot problems.

I plan to get the battery load tested tomorrow. I have done as much inspecting as I can on the Power Lead from the battery to the starter to see if there is anything compromised in it but it looks good as far as I can tell... I may go ahead and just replace it anyway bcs it's a pretty cheap way to eliminate one potential aspect of the problem.

When I bench tested the starter, I was using the same battery that is in the truck.

I like the plan of trying to replicate the bench test with the jumper cables while the starter is mounted in the truck. Not sure if the space will allow for me to get the jumper cable onto the post of the solenoid without touching anything else, but I'm up for the challenge - and a spark or 2. I will try this as soon as I have the time and let you know the results.

I reached out the guy I bought the truck from and he didn't know of any anti-theft system on the truck.... I had wondered the same thing as well.

Not gonna lie - I'm loosing steam to get this figured out... and feeling quite discouraged and inept by the dead ends. Glad for this community and the help found here. Without it, I would be at whits end (even more than I already am)! I'll keep you posted on what I discover about the battery. Thanks for your steadfast help

@Caman96 , I have a question for you too: I repainted the bracket that holds the wire harness on the back side of the engine - the ground bolt attaches through this bracket (see image and the red arrow I added to show what I mean). Would painting this surface compromise the ground or is the grounding handled by the stud that is threaded into the header even if the bracket is painted?

I think it’s fine and like you said the bolts are threaded into the head.

DHud said:

That's good stuff, @Road Trip - thanks for the deep dive into the starter mechanics. I appreciate understanding how things work bcs it helps to troubleshoot problems.

Click to expand...

Dhud,

We used to learn that stuff because back in the day we used to replace either the starter solenoid or the starter motor, but not both.
Obviously times have changed, and we no longer make $3.50/hr. :0) But in your case, if the starter only gets halfway through
the sequence & quits, we need to know which of the 2 electrical circuits to blame, or possibly a mechanical interference issue, and dig deeper there.

DHud said:

I plan to get the battery load tested tomorrow. I have done as much inspecting as I can on the Power Lead from the battery to the starter to see if there is anything compromised in it but it looks good as far as I can tell... I may go ahead and just replace it anyway bcs it's a pretty cheap way to eliminate one potential aspect of the problem.

When I bench tested the starter, I was using the same battery that is in the truck.

Click to expand...

That's encouraging news about using the same battery! As a matter of fact, you being able
to get the starter to operate correctly on the bench using the same battery is valuable troubleshooting info.

Using the same battery and starter/starter solenoid assembly, the only 2 variables
between the bench test and bolted into your truck are:

* Different electrical cables in use.
* The starter was throwing the bendix into free air instead of meshing with the flexplate ring gear.

You know, these post engine swap troubleshooting sessions can try the patience of even the most seasoned
mechanic, for you are trying to get a collection of parts from 2 different vehicles to play together nice in one, so there are so many
more possibilities for stuff not to add up correctly. It's a way different scenario than when Old Faithful has the starter fail, and
that's the only thing that gets changed in the engine bay. Q: Does this make sense?

****

So we're in this pretty deep, but the fact that you now have a working battery > cabling > starter combo on the bench is a big win.
So let's use this combo to help troubleshoot your truck.

Since we're still in troubleshooting mode, we still have 2 possible scenarios:

1) Electrical: Ideally, you would install the battery > same test cables > starter back into your truck. And it still works!

Now you need to figure out which of the truck's power cables is not working as well as the test bench cables,
and fix that. (And when you find the problem, please take pictures of the failing spot and post those here for
others to learn from.)

2) Mechanical: Given that you have actually cranked this engine over with this starter previously (to build oil pressure) ...the
following is a very low probability scenario, but just in case the starter still won't turn over even while installed &
using the jumper cables? What if there is some sort of tolerance stack up or misalignment where the starter bendix
jams up on the flexplate ring gear. And when this too-little travel occurs, the big power contacts are never made, and
the motor never gets the power to spin? Here's a close up photo showing the physical relationship between the starter pinion gear
and the flexplate's ring gear:


(credit: chevyhardcore.com starter article)

DHud said:

Can a starter engage with no load and falter like this when put under load? Will a parts store do more extensive testing on a starter to reveal something deeper?

Click to expand...

Note the bevels cut into the leading edges of the starter's pinion teeth. These are designed to align the gears as
they are forced together so that they will mesh without fail. If the starter is aligned correctly when it's bolted up,
the starter pinion teeth aren't all chewed up, the flexplate isn't cracked, the ring gear isn't chewed up or suffers
from excessive runout...then this high-speed meshing should occur reliably for thousands of starting cycles.

So with this in mind, here's a few more questions for you:

* You swapped out a 350,000 mile engine for a less worn 100,000 mile motor. Is the flexplate (assuming automatic) from
the original motor or did you use the flexplate from the replacement motor?
* Which starter did you use? Have this starter & flexplate worked together before, or is this a new pairing?
* When you were cranking the engine over to generate the initial oil pressure, how did the starter sound? Is it bolted
directly to the block, or were there shims in place?

NOTE: All these questions are me simply trying to figure out if there is any reason why the starter bendix isn't being
allowed to throw the pinion gear all the way home and simultaneously get the big power connections to close and
allow the starter motor to rotate. And since this starter has already turned over this motor previously my assumption
is that all of the mechanical clearances involved are OK.

But anyone reading this who has had a high mileage starter with a weak solenoid that would click instead of start, and after a couple
of whacks with a mallet the starter could be persuaded to work a little longer. They would tell you that it's possible to have a weak/flaky
starter that was fixed with a new unit. And to answer your question about the store's bench testing vs what you just did, the answer is
mostly no. They also just have the starter drive the pinion gear into thin air.

Once in awhile you will meet someone who will measure the amps drawn by the starter during testing, but that's pretty rare these
days.

DHud said:

I like the idea of trying to replicate the bench test while the starter is mounted in the truck. Not sure if the space will allow for me to get the jumper cable onto the post of the solenoid without touching anything else, but I'm up for the challenge - and a spark or 2.

I reached out the guy I bought the truck from and he didn't know of any anti-theft system on the truck.... I had wondered the same thing as well.

Click to expand...

I appreciate your can-do attitude. Sometimes the only silver lining to a situation like this is that you end up learning a
lot more about how stuff works than you expected to at the outset. :0)

DHud said:

Not gonna lie - I'm loosing steam to get this figured out... and feeling quite discouraged and inept by the dead ends. Glad for this community and the help found here. Without it, I would be at whits end (even more than I already am)! I'll keep you posted on what I discover about the battery. Thanks for your steadfast help

Click to expand...

Not a problem. If I cross paths with someone who's trying hard to keep one of these old gems on the road
I have a lot more in common with them than the person who just washes their hands of it & trades it in on a newer
vehicle. I know that this has been a long process to go through, but I just hate to tell others to throw parts at a
problem before the troubleshooting is completed.

To recap, if the test bench setup is installed and it now works, then you need to look closer at the truck's high power
positive and ground cables for excessive resistance anywhere in the circuit.

And if the test bench setup still doesn't work now that the starter is installed, then the issue may be a mechanical
gear meshing issue that isn't allowing full travel to occur.

Fingers crossed that the setup now works with the jumper cables temporarily substituted in place. (And this is what
I'm expecting since this starter has successfully cranked over this engine before.)

Best of luck --

Road Trip said:

Q: Does this make sense?

Click to expand...

Makes total sense - I’m impressed at how well you explain complex things - you should be a shop teacher!

Road Trip said:

* You swapped out a 350,000 mile engine for a less worn 100,000 mile motor. Is the flexplate (assuming automatic) from
the original motor or did you use the flexplate from the replacement motor?
* Which starter did you use? Have this starter & flexplate worked together before, or is this a new pairing?
* When you were cranking the engine over to generate the initial oil pressure, how did the starter sound? Is it bolted
directly to the block, or were there shims in place?

Click to expand...

*Flexplate is from new motor - automatic
*Starter is original from the old motor, new pairing with this engine
*Starter sounded normal/strong/no hesitation - no shims installed with original motor

Road Trip said:

I just hate to tell others to throw parts at a
problem before the troubleshooting is completed.

Click to expand...

I appreciate that. We are on a tight budget with a big family - one of the reasons we run old cars (and the fact that I prefer them : ) There are probably some who are reading this exchange who are thinking, just replace all the stuff with new and move on. I’m getting there myself, but I really want to know the specific reason this isn’t working so I’m better equipped in the future.

I’ll get back to you when I have the chance to try the test set up in the truck.

X2…this forum is lucky to have @Road Trip