23R-E in 1988 Toyota 4wd pickup
Starter failed intermittently worse & worse.
Fixed several problems, (new battery, bad low current connections etc.) got the solenoid to click.
Replaced solenoid contacts. Seemed really straight forward.
Before reinstalling I hooked starter/solenoid up with jumper cables and used a small wire to activate solenoid. NO CLICK
I reinstalled the old contacts. No Click
I disassembled the whole thing and could not find anything wrong.
All wire connections have reasonable resistances and no shorts to ground.
Swapped back to the new contacts. It's now in my lap.
When I apply 12V to the control coil I get a nice little spark that seems about like the 12 amps I expected.
I can feel the plunger try to pull in firmly and see it move.
But, it does not pull hard enough to extend the pinion gear nor to close the main contact. Nor to compress the skinny little compression spring. Still No Click
I'm stumped. Any Ideas? I hate to spring for a new starter but I may have to even though it is against my religion.

 

You need a good ground when you're bench testing (even harder when lap testing).

Even the though the solenoid wire carries a lot less current than the main power wire, it's still a fair amount. If your wire is too small it can't drive the solenoid.

This is really a job for your multimeter. Do you have continuity to ground through the solenoid lead? With your small wire, do you still get at least 6 volts or so to ground at the solenoid connection?

 

Like Scope says ^^^
I measured current to energize the starter solenoid to be approx 24 amps.
On the truck, ground is through the very thick cable to engine block.
Also, the starter relay on the 1988 was wired wrong AT THE FACTORY. $15, 30 minutes to fix it.

Starter Relay on 1988 22R-E WIRED WRONG FROM THE FACTORY. Search "ClickNoCrank"

 

I'm using a jumper cable capable of starting a V8 directly from a battery (on a working vehicle) to the starter case and to the big solenoid connector.
And a test jumper about the same diameter as the control wire in the engine, with alligator clips, that has been reliable for years, directly from the battery to the small connector on the solenoid.
No fooling around with the little relay that sometimes goes bad. I took it and everything else confusing the issue out of the circuit for the test. Just using the starter & battery.

What is the resistance of the solenoid coil supposed to be? I'm getting about 0.3 Ohm.
Why does it seem to be grounded through the starter motor? (this is the internal starter wiring that would be hard to and stupid to change)
What is the resistance of the starter motor supposed to be? I'm getting about 1.1 Ohm. The brushes and everything else look good.
Yes, I have continuity.

 

You seem to be doing all the right things. Those resistances seem right. starter motor winding is thick wire, so 1 or so ohm is correct.
Starter solenoid not pulling plunger in nor closing contact, while using god cables, either means weak battery or bad starter solenoid.



In my 9 years as forum member have only seen one starter relay go bad - LOL​​
People pick on that poor thing because they do not know any better. The starter relay may sometimes go bad. The wiring I describe above that is documented in FSM is ALWAYS bad.

 

Hooking the solenoid up with the cover off I can feel it pull firmly but not strongly enough to move the gear into its engaged position.
Gear does not feel jammed. I can push it out easily but firmly with one thumb.
The solenoid coil will pull the plunger out of my fingers unless I get a good grip on the slick chromed 1/2" diameter section.
Both the old and new plungers.
I'm tempted to see how it works without the 2" long 1/8" diameter spring in the middle of it.
I can't see what it would hurt for a test.
OK so I tried it without the little spring. Same results. No Click. No Movement.
Voltage on small jumper wire terminal while connected was 11.06V
The only thing I can think of now is to bite the bullet and install the thing and see if that works.


Should work, Right?

 

With that setup, off the truck, solenoid should clunk, contacr should close, actuator should move the gear and motor should turn.

 

Yup. That's what I thought. It's not rocket science.
That's why I'm so bamboozled.