Diagnosing failing ignition coil vs starter solenoid - click when turning key, cranks after multiple attempts

[CSX55]

My '99 Tahoe has been getting increasingly more hit or miss when it comes to starting. Turn key, single click, but within a few more turns/clicks, it'll turn over as normal. Battery is in good shape, all terminals are tight.

Today, it got to the point where it took probably 30+ attempts to finally crank - still getting just a single click upon each attempt. Trying to determine if I should be looking at the starter or the ignition coil; any advice on how to compare the failure modes? I've read conflicting reports on whether a bad ignition coil will produce the click. Hoping it's a starter given that it's comparatively simple to R&R.

Thank you!

 

[SUBURBAN5]

Is the starter original?

 

[Erik the Awful]

From your description, the most likely culprit is a bad connection. Did you put a battery brush in the battery terminals to ensure they're clean? Is there any crud growing back into the wires? Is your engine grounded well? How do you know the battery is good? Did you use a battery tester that puts a load on it?

Not trying to cast doubt on your abilities, just asking the simple questions first. It's possible your starter solenoid's contacts aren't contacting reliably, but it's usually a battery cable issue.

 

[HotWheelsBurban]

The battery cables on these trucks are notorious for getting corrosion down inside the insulation where you can't see it. I've had this happen on my Burb in early last year. Like Erik said, the starter solenoid could be bad, but check your cables and grounds.
If you can get the starter off, do you have a way to get to a parts store that can check it by running it on their tester? Sometimes a bad starter has to be checked several times, so that it's warmed up good, to verify that it has a problem that may only present when the unit is hot.

 

[stutaeng]

I think when my starter went out it just didn't do anything. I was at work and when my wife showed up to pick me up I remembered the old trick of wacking it with a hammer.

I had my wife continuously engage the ignition switch while I tapped the starter with a wrench and she started right up. When I got home I headed to the local parts store for a remanufactured replacement.

On the same truck but much longer time ago a little after I had bought it, my ICM died and the truck stalled, leaving me stranded. Luckily I was a few blocks from home and Dad pulled me home with his truck. I was so green then that I didn't even know how to do basic things such as checking for spark. My mechanic quickly figured it out though.

 

[Erin]

I think when my starter went out it just didn't do anything. I was at work and when my wife showed up to pick me up I remembered the old trick of wacking it with a hammer.

Same here. I bought a battery first, thinking that was the problem. My dad suggested starter, which I hadn’t even considered. So, I ended up with a new battery & starter.

 

[PlayingWithTBI]

Sounds like a dead spot in the starter to me too.

 

[stutaeng]

Yeah, definitely look at the starter. I went back to re-read your post and realized that the ICM would not be the problem in your case. ICM is responsible for sending signal to the coil to produce spark. What you describe is that truck fails to turn over, right?

Get yourself a test light and go underneath and check for ground, 12V+ and the signal. Ground and 12V+ should always be present on those big cables. The signal wire goes to the solenoid. Have a helper cycle the ignition while you check for power. You can use long test leads and locate the test light on your dash if you are working solo. That would conclude if it's the starter or some other thing like a relay or ignition switch.

 

[GoToGuy]

Test ignition control module, good battery, good cables power and grounds. At starter ensure full voltage to solenoid control wire. Solenoid engages than next would be motor. Breaking down winding s loss of field voltage?

 

[454cid]

Test ignition control module...

His ICM, good or bad, is not preventing his engine from cranking.

OP, that sounds like the starter, or the starter solenoid. If it's the solenoid, I suggest just getting the whole starter. It's possible it could also be the trigger wire, but I've never experienced that.

When mine went, it would always start right up at home. Then when I was elsewhere it would be dead, and I'd have to hit the key many times. When it was getting to the end, hitting the starter while turning the key would get it going... unfortunetly that's a two person job. When I tried taking my soliniod off the starter I started snapping the little bolts, so I just got a new starter. Later, I found the contacts in the solenoid were completely worn out.