76 bronco DESTROYING starter solenoids!!! HELP!

[DirtDonk]

Yep, I bet he could fix just about anything then.

Mark, that's a great recommendation! Not a bad price either, if what you're getting is the same thing as they put on the hospital generators.
Or do they replace them on a set schedule so they never get old anyway? Or just leave them until they fail? Seems like scheduled replacements would be the practice.

Paul

 

[ntsqd]

My wife is more or less in charge of one of those clinical emergency generators (along with everything else for the clinic). They start it once a month and check for correct operation. Any poor performance is immediately reported and addressed by the vendor.

 

[Steve83]

...the wire strand between the main contact and the "I" post?

No such thing. If there was, the I terminal would always be +12V. On this one, you can see that I is connected by a flexible strap to the Copper washer:


(phone app link)

On others I've opened, I is an independent small contact that the washer also touches when it comes up.

The only "tiny" wire is from S to the relay's coil, which is then welded to the mounting tab for grounding.

 

[blubuckaroo]

Again, here is a good time to consider one of the smaller gear reduction starters. With that starter, that solenoid doesn't see any starter current at all. Even the cheapest solenoid should last forever. You can even get by with a smaller battery.

 

[ntsqd]

When we did the Ford starter solenoid trick on chevies we always wired them so that full starter current went thru the Ford solenoid. We jumpered the chevy solenoid 'S' terminal to it's B+ terminal & moved the 'I' wire up to the Ford solenoid. Some claim that it's the wrong way to do this, but that is really not any different from how the Ford starter works and it worked just fine like that on many years on many cars.

 

[DirtDonk]

It's not exactly "wrong" in a wiring sense ntsqd. And it's probably fine for GM products of the day. But it's indeed a problem on Broncos, and for probably more than half of the Broncos that get wired that way, they experience starter run-on after the key is released.

Sure, it works, but if run-on happens even once that's one time too many.
So if you wire one that way and it works, great. But if not, then it's definitely time to put it over to the recommended way.

Paul

 

[DirtDonk]

No such thing. If there was, the I terminal would always be +12V. On this one, you can see that I is connected by a flexible strap to the Copper washer.

On others I've opened, I is an independent small contact that the washer also touches when it comes up.

Thanks. I worded it wrong, and also remembered which side it was on incorrectly. But by "main contact" I was referring to an area that the main plunger contact hits when the relay is energized. Not at some point that is always hot.
But yes too, I remembered the small wire as on the I post, but as you pointed out it's on the S post.

The only "tiny" wire is from S to the relay's coil, which is then welded to the mounting tab for grounding.

Gotcha. All I remembered was that there was this tiny single-strand conductor under the cover. Still kind of surprised at that, but it apparently works.
I wonder if the better quality ones use at least a larger gauge conductor, or if it's the same slender thread that I've seen.

Thanks

Paul

 

[Steve83]

That's the electromagnetic coil wire. A thick wire has less resistance, and takes up more space. Meaning it will generate more heat than magnetic field. The finer wire has more resistance (draws less current), and can be wrapped more times in the same space, creating a stronger field to pull the plunger/contact up.

 

[ntsqd]

It's not exactly "wrong" in a wiring sense ntsqd. And it's probably fine for GM products of the day. But it's indeed a problem on Broncos, and for probably more than half of the Broncos that get wired that way, they experience starter run-on after the key is released.

Sure, it works, but if run-on happens even once that's one time too many.
So if you wire one that way and it works, great. But if not, then it's definitely time to put it over to the recommended way.

Paul

I am guessing that the distinction is not Ford vs. GM starter, but rather gear redux vs. direct drive starter armature. With a gear redux I can see where the armature speed could be high enough to cause the starter to work as a poor generator, but one that could generate enough power to keep the solenoid engaged. Interesting.

In that case I wouldn't bother with a starter solenoid at all. Use a std "sugar cube" relay to drive the starter solenoid's 'S' terminal.