Starter problem

[CavScout]

The GT has developed a problem with the starter. Done this with the OEM, an Autozone reman, and Powermaster 9200 starter.

The bendix will kick out, clunks against the flexplate and doesn't turn to engage.

Swapped 2yr old Optima battery (held charge at 12.6v, ukn craking amps) for the AGM Duralast, positive battery cable swapped for new, grounding point on block for starter and negative battery cable have been sanded clean. Checked bendix gap for need of a shim, didn't…but tried one anyway.

The starters (plural) still do the same thing. Kicks out, hit the flexplate and that's it. What am I missing?

 

[Don W.]

Re: Starter problem

Going only by what you've said. If by "kicks out" you mean it tries to engage and just won't turn the motor over then check to see if you can turn the motor by hand. You can also try to make sure the starter runs on the bench but after three different I doubt it's that.

Does everything else electrical work? Have someone help and watch what the headlights do when you engage the starter. Find a clamp-on amp meter and check the amperage draw of the starter.

 

[CavScout]

Re: Starter problem

I've had no other electrical problems thus far. The motor can turn by hand, I moved the flexplate to check bendix clearance with a flathead screwdriver.

I've even pulled out and apart the GM installed security/ door lock system to watch the relay in it operate. Which it does.

However, the ammeter check I haven't done. I don't have a fieldpiece multimeter. Just a Klien probe style and it's only rated to to 10A. So I'm at a loss doing that. I just don't understand why it'll slide out, tap the flexplate and stop.

 

[mattw]

Re: Starter problem

Do you have an external solenoid wired in? I've seen them cause some weird issues...

 

[0966Sy]

Check voltage at the solenoid while cranking, I bet you have an excessive voltage drop.

 

[Don W.]

Re: Starter problem

Check voltage at the solenoid while cranking, I bet you have an excessive voltage drop.

Actually this will work quite well also. (Instead of the amp meter.) One probe on on engine ground. And when you touch the starter make sure you touch the actual post itself. This will be a "true" reading of what the starter is getting.

Which brings another thought. The engine, with starter attached, has lost its ground. Check resistance between block and actual neg post. It should be -0-. I know you said you've cleaned etc but check to be sure.

 

[CavScout]

Re: Starter problem

Do you have an external solenoid wired in?

No, I don't. Full disclosure: GM Put the old Code Alarm system in this truck and used a Rear Defog dash switch for the ground side of the purple wire relay in the alarm box. That relay works, and the solenoid on the starter works.

Don, I'll try both tests this afternoon when I return from der werkplatz. Thanks for the help guys!

 

[T-Bone]

Re: Starter problem

Leia simply misses home. Send me a PM if you wanna sell her back to me. Cheers.

 

[CavScout]

Re: Starter problem

…you wanna sell her back to me.

Hush that mess. She's just not feeling well.

Though voltage/ amparage drop was something I thought of, ground resistance was not. Continuity was. That's why I sanded all the grounding areas/ wires and swapped the positive battery cable. The OEM ground wire is still on it.

 

[Don W.]

Re: Starter problem

Voltage is the amount of "push" the electricity has, Amperage is the amount of "flow" and ohms is the resistance to flow. Every connection and length of wire has resistance. Might be small but it's there. More resistance and you have less amperage at a given voltage. So with no load you can put 12v in one end of a tiny wire and still have 12v on the other end. Start adding load and everything changes.

What seems odd to me, if I understand correctly, is the starter engages correctly and just doesn't turn the motor. No "click-click" no nothing. Motor just doesn't turn over. If correct we're missing a clue somewhere. Keep testing. You should be able to get an inexpensive clamp-on amp meter from Harbor Freight. Readout won't be exact but close enough to see what's happening. Or borrow one.

It will take a helper but also make sure that the solenoid term on the starter is getting bat voltage, or very close to it, with key in the start position. Just one more thing to check.

 

[Ty1642]

Re: Starter problem

I wonder if you are having the "purple wire" issue. All the switches and contacts in the solenoid circuit eventually start limiting how much current can flow to the solenoid as they age/get dirty. My truck just started doing this - it would "click" but nothing else. The purple wire does need to flow enough current to close the solenoid solidly. The standard fix I did was to use the wire to the solenoid to close a relay instead. That relay then supplies power from the 12V source on the firewall to the solenoid. That circuit has less resistance so it can supply more current to the solenoid.

 

[Don W.]

Re: Starter problem

I wonder if you are having the "purple wire" issue. All the switches and contacts in the solenoid circuit eventually start limiting how much current can flow to the solenoid as they age/get dirty. My truck just started doing this - it would "click" but nothing else. The purple wire does need to flow enough current to close the solenoid solidly. The standard fix I did was to use the wire to the solenoid to close a relay instead. That relay then supplies power from the 12V source on the firewall to the solenoid. That circuit has less resistance so it can supply more current to the solenoid.

You could be right and you ARE correct in your comment about holding the relay in fully. That mod has been done many times here. Do a search and you'll see all kinds of versions. The usual symptom is the starter will kick in then as soon as "run" load is placed on the system voltage drops a little and the solenoid kicks back out. The infamous "purple wire, click-click" issue. He seems to say the starter kicks in and stays there. That would at least indicate the solenoid and purple wire are functioning correctly. But to be sure I suggested he check that. (The last line in my post.) It will interesting to hear what this turns out to be.

 

[CavScout]

Re: Starter problem

I have already replaced a section of the purple wire, over 2 years ago. Way back at the 1st indication of this problem happening. The insulation was loose from the internal wire so I repaired/ replaced it with high temp wire, used new corrugated loom, then covered the section that passes under the exhaust manifold with heat reflective sleeving.

 

[Ty1642]

Re: Starter problem

There is a post from DaveP somewhere on here that talks about the extra switches and extra wire lengths in a SyTy starter circuit compared to a regular S10. Changing the length of wire to the starter helps a bit, but all those other switches can still be getting worse. Maybe a quick test would be to connect a wire to the solenoid terminal on the starter, and touch the other end to the positive battery terminal.

My truck would just click once and then nothing. I wonder if the click was the gear extending like yours.

 

[Slyclone]

Re: Starter problem

Here's a good old pic from my truck.

Glad I found the eff'ing thing. Power wire worn down severely, made contact grounding out a small explosion occurred.

Truck would act up.

This wound was hiding so it wasn't something I found right away. If you look you can see my flywheel so it was towards the back.... Some where to look? I thought it was my purple wire but it wasn't. It was the bigger main power wire carrying more of a load.

 

[Don W.]

Re: Starter problem

Ya, I don't know if Typhoons are any different but the Syclone cable arrangement is very poor.

 

[CavScout]

Re: Starter problem

I've already replaced the positive cable. Removed/ inspected/ reinstalled the negative.

This is on a SGT. Positive cable drops from the battery, goes to the front of the block, then directly to the starter. The only extra switch is the deadman that GM installed. It's for the security systems relay, ground side for that relay and carries no current for the purple wire.

 

[T-Bone]

Re: Starter problem

Hush that mess. She's just not feeling well.

Heehee. Glad you are still alive and kicking, my friend. Perhaps we will meet up next year. The SGT and the red prototype Sy are 2 I wish I never let go but both you guys pamper each one respectively and for that, I am very pleased. Hope you help her back to good health soon.

 

[0966Sy]

Starter problem

I have already replaced a section of the purple wire, over 2 years ago. Way back at the 1st indication of this problem happening. The insulation was loose from the internal wire so I repaired/ replaced it with high temp wire, used new corrugated loom, then covered the section that passes under the exhaust manifold with heat reflective sleeving.

How did you repair the purple wire the first time? Check voltage to the solenoid and battery supply voltage while cranking. Butt connectors will tend to come loose, break wires and corrode which could cause a voltage drop on the purple wire that would cause the solenoid not to fully engage the bendix into the flywheel teeth

 

[Don W.]

Re: Starter problem

I've already replaced the positive cable. Removed/ inspected/ reinstalled the negative.

This is on a SGT. Positive cable drops from the battery, goes to the front of the block, then directly to the starter. The only extra switch is the deadman that GM installed. It's for the security systems relay, ground side for that relay and carries no current for the purple wire.

This is a bit confusing. What exactly, is "switched" by this relay? Or, even better how is the relay activated?