Starter bench test...problem solved (1 Viewer)

[Malleus]

Starter bench test:

I've completed the cleaning and solenoid rebuild on Charlie's '95. The starter passes all the tests, except the full load operation test (I didn't connect the ammeter). I can get the solenoid to operate perfectly, and the motor spins, but I can't get it to spin when the solenoid pushes the gear out. What am I doing wrong?

View attachment 2985708

I remember having this problem when I bench tested my 80 series 2.0-kW starter years ago, but I don't remember what the problem was, or how I solved it. I'm pretty sure everything is fine, but I'd like to know that before I bolt it back in.

 

[FMC80]

You’re so helpful for everyone else, wish I can help. I can’t but here’s a bump

 

[Malleus]

Yeah, that thought crossed my mind...

 

[Eyedaho]

Starter bench test:

I've completed the cleaning and solenoid rebuild on Charlie's '95. The starter passes all the tests, except the full load operation test (I didn't connect the ammeter). I can get the solenoid to operate perfectly, and the motor spins, but I can't get it to spin when the solenoid pushes the gear out. What am I doing wrong?

View attachment 2985708

I remember having this problem when I bench tested my 80 series 2.0-kW starter years ago, but I don't remember what the problem was, or how I solved it. I'm pretty sure everything is fine, but I'd like to know that before I bolt it back in.

How are you bench testing? Are you using a known good battery? I had an issue before where I didn't have enough CCA to bench test my starter and it would engage the solenoid but not spin. Testing it on my charged vehicle battery fixed that problem.

 

[Malleus]

How are you bench testing? Are you using a known good battery? I had an issue before where I didn't have enough CCA to bench test my starter and it would engage the solenoid but not spin. Testing it on my charged vehicle battery fixed that problem.

AFAIK, the battery's good. It's fully charged, but I have no way to test the cranking amperage.

 

[Kernal]

Can you take the starter to a parts store and have them put it on their testing machine??

Was it working well before you replaced the contacts? Did you also replace
the plunger (with the correct part number)??

 

[Malleus]

Can you take the starter to a parts store and have them put it on their testing machine??

Was it working well before you replaced the contacts? Did you also replace
the plunger (with the correct part number)??

Yes, I suppose I could; honestly, I hadn't thought to do that.

Yes, it was working. However, after inspection I deteremined that I caught it before it left me stranded. It may have had another year on it, maybe less. All the wear parts were worn past my acceptable limit, except the motor brushes. They looked like they are only half way there.

This was a part of the long list of preventive and corrective maintenance I'm doing while the head's out. Yes, all the parts are correct; I used the rebuild kit from Alternator Starter Parts Wholesale. As I said, the solenoid moves the driven gear in and out, and the starter motor spins, the two just don't happen at the same time.

 

[Kernal]

That's a bit unusual; when the solenoid is energized it magnetically pulls
the plunger down/in and that pushes the pinion shaft in the center of the clutch drive out. So that's where there might be a problem, but it requires you to pull the starter apart again.

Can you pull the pinion gear out with your fingers? Is is difficult to pull out
or easy? Does it rotate in one direction or both when it's pulled out?

Maybe start by having it tested on the test machine at Auto zone, O Reillys, Ad vance, etc, to see if the symptoms are the same as when you do a bench test??

 

[Dave 2000]

Please don't take this wrong as I know you are quite knowledgeable.

Leave the battery positive connected to the starter main terminal and of course the negative to the starter body, then run a cable from there to touch on the solenoid terminal, the solenoid should throw the pinion out and the starter spin, it will give quite a kick as well.

If that is not happening then the contacts are not seated/installed correctly......or and I have seen this before, the plunger does not move within the solenoid because the arm that the pinion is connected to is binding, the solenoid may not be able to overcome this to bring the contacts together, also the push rod on the plunger might be too long pushing the pinion out to it's limit before the contacts meet, this is the most common problem.

I am a little misty on this stuff these days but it will not be the first time a rebuild kit has mixed up parts because there are loads of Land Cruiser starters that share the same parts and may have just one specific part that suits that starter only.

I think I am getting it across.....well in my mind. LOL!

Stay safe

Regards

Dave

 

[Malleus]

That's a bit unusual; when the solenoid is energized it magnetically pulls
the plunger down/in and that pushes the pinion shaft in the center of the clutch drive out. So that's where there might be a problem, but it requires you to pull the starter apart again.

Can you pull the pinion gear out with your fingers? Is is difficult to pull out
or easy? Does it rotate in one direction or both when it's pulled out?

Maybe start by having it tested on the test machine at Auto zone, O Reillys, Ad vance, etc, to see if the symptoms are the same as when you do a bench test??

Yes, the pinion gear comes out by hand, and the clutch does work; it freewheels in one direction and in the other it locks and turns the motor. I'll let you know what the parts store test shows.

another thought just came to mind; my test leads are 18ga wire, and they get hot immediately, even though the test is momentary. I wonder if they aren't capable of carrying enough current to energize the solenoid AND spin the motor at the same time.

EDIT: well, on second thought, that doesn't makes sense. I just checked the conductor sizes on the engine harness. Both the ground and positive conductors are the same size as my test leads.

 

[Malleus]

Please don't take this wrong as I know you are quite knowledgeable.

Leave the battery positive connected to the starter main terminal and of course the negative to the starter body, then run a cable from there to touch on the solenoid terminal, the solenoid should throw the pinion out and the starter spin, it will give quite a kick as well.

If that is not happening then the contacts are not seated/installed correctly......or and I have seen this before, the plunger does not move within the solenoid because the arm that the pinion is connected to is binding, the solenoid may not be able to overcome this to bring the contacts together, also the push rod on the plunger might be too long pushing the pinion out to it's limit before the contacts meet, this is the most common problem.

I am a little misty on this stuff these days but it will not be the first time a rebuild kit has mixed up parts because there are loads of Land Cruiser starters that share the same parts and may have just one specific part that suits that starter only.

I think I am getting it across.....well in my mind. LOL!

Stay safe

Regards

Dave

@Dave 2000 thanks for the comments; at this point I'm at a loss to identify the problem and can use all the ideas that come.

I'll break it down and check the solenoid contact positions once again. FWIW, this type of starter doesn't have the pivot arm, some do but this type uses an inline connection to the driven gear from the solenoid plunger. This is from the Denso starter manual (the Landcrsuier starters are the reduction type on the left):

 

[BILT4ME]

@Dave 2000 thanks for the comments; at this point I'm at a loss to identify the problem and can use all the ideas that come.

I'll break it down and check the solenoid contact positions once again. FWIW, this type of starter doesn't have the pivot arm, some do but this type uses an inline connection to the driven gear from the solenoid plunger. This is from the Denso starter manual (the Landcrsuier starters are the reduction type on the left):
View attachment 2993383

I assume you followed the FSM for the test, right?

 

[Dave 2000]

If the leads are getting hot then you have a short in the solenoid or across the contacts in the starter.

Regards

Dave

 

[Malleus]

I assume you followed the FSM for the test, right?

View attachment 2993393

Yeah, it's in post #1

 

[Malleus]

If the leads are getting hot then you have a short in the solenoid or across the contacts in the starter.

Regards

Dave

That's the answer I was looking for. Thanks Dave.

 

[Kernal]

The parts store bench test print out (test results) would be interesting to see
if they give you one. IME some stores can print out the results, some only display them on a screen (but you can take a photo of that screen).

FWIW.

 

[blkprj80]

@Malleus If you're trying to perform the no load performance test you attached with an 18 gauge test lead wire, that's why it isn't working. The last test says to look for 90 to 100 Amps. For that, you'd need jumper cables. 18 Ga can carry maybe 10 amps.

This (from you):
"another thought just came to mind; my test leads are 18ga wire, and they get hot immediately, even though the test is momentary. I wonder if they aren't capable of carrying enough current to energize the solenoid AND spin the motor at the same time."

Apologies if I misunderstood what you meant.

 

[flintknapper]

@Malleus If you're trying to perform the no load performance test you attached with an 18 gauge test lead wire, that's why it isn't working. The last test says to look for 90 to 100 Amps. For that, you'd need jumper cables. 18 Ga can carry maybe 10 amps.

This (from you):
"another thought just came to mind; my test leads are 18ga wire, and they get hot immediately, even though the test is momentary. I wonder if they aren't capable of carrying enough current to energize the solenoid AND spin the motor at the same time."

Apologies if I misunderstood what you meant.

I always use either jumper cables or the leads of my battery charger to supply power to the starter and a 12 ga. jumper wire to the solenoid to bench test. Should work fine for everyone.

 

[Kernal]

Would be interesting to know if the problem was just the guage of the wire.

 

[Malleus]

Would be interesting to know if the problem was just the guage of the wire.

So to be clear, the insulated 18ga jumper wires I'm using do not heat up when they are connected to the starter in the "installed" configuration, that is, ground wire on the starter frame, hot lead to both the solenoid and ignition connections. In this configuration, the solenoid is energized and the driven gear will extend, but not spin.

In the momentary (3 second) motor test configuration, ground to starter frame and hot lead to motor lead, the motor spins and the insulation gets so hot I can't hold it. @blkprj80 is on to something in that the current carrying capacity of my jumper wires is far below 90 amps, so I'm going to go out on a limb and say the full load is near there, even if the starter doesn't pass the function test. FWIW, the internal wiring from motor to solenoid is much larger than my jumpers; something like 6ga or 8ga, IIRC.

Advance Auto's starter tester gave the same results as my bench test; the solenoid energizes and extends the gear, but the motor will not spin.

At this point, I think I'm looking for an open circuit between the motor and solenoid. I'll pull it apart later tonight and check, although I would have thought the first two continuity checks were supposed to find that, if it existed.