Speedtoys

Every ground point in the car, and the rings on every cable to every ground point (A few are a bitch, passes on those..but are obtainable with the pod out)
And the various power distribution points, and the terminal rings on those, including the connections to the CE Panel?

Just helping to cross these off the list.

I post these things, and it's not until someone else asks the same, then you have a response much of the time.

just going down the path of helping us understand the entire picture with the go-to items that must be done.

merchauser

certain I have not hit every ground, but I have gone thru a majority, for sure. biggest mistake was ignoring the battery ground.

Jason89s4

Two .pdfs in post #13 with ground points.
I'm not kidding that I have one on the wall in the bay next to the 928.
It's that important. It has my checkmarks and notes with dates. (I've added ground "dots" to it as well.)
Jason

merchauser

does heat, either engine heat and/or ambient heat play any part in poor ground behavior?

this AM, temps were in the low 70's and I did everything I could to induce my stalling situation to no avail. what is the relationship between heat and voltage issues?
my volt gauge did not budge from midway of 12 and 14, which is my default, as I added load items, one at a time. when I have my stalling, each accessory added drops voltage.

docmirror

Heat relatively speaking plays a minimal role in conductance. If we were talking about -35 to 265F, then it might be an issue, but 20-30F change shouldn't affect the circuits enough to cause wild changes in how it works. More than likely, you have an intermittent connection somewhere that fixes itself and then will degrade, and then fix, and degrade. They are very hard to find. Everyone has advised you on the ground checking, and you've done most of that, so you may have resolved it and didn't know which one was the culprit.

Finish up the ground cleaning and keep driving, see if that solved it. If not, we'll dig in some more.

Jason89s4

Did you do anything to the car since your last post?

Yes, heat can play a role in the performance and efficient operation of all things electrical. Temperature change may not affect the quality of your ground per se, but it will affect the efficiency of the electrical component that is relying upon that ground being good. So, in an indirect way, heat or cold may magnify or mask you poor grounds.

(One of the most common heat/electric issues on cars of all makes is called "heat soak." If you drive your car around on a hot day and then park it, the trapped heat under the hood, no moving air, no moving coolant, will actually cause engine temperatures to rise for a while (several minutes) as your engine becomes a heat sink. A common example is drive around, park and come back out ten minutes later and it won't start. But if you wait thirty minutes it will. This is from the starter solenoid becoming "heat soaked" and it won't work. This mostly likely will happen to a "weak" solenoid or more commonly a hot starter and solenoid that is "begging" for more amperage to help it out and not getting it....why? because the the cables are not tight and clean and corrosion free! I literally just fixed a 2009 Ford Fusion this past weekend with this issue. Cleaned the battery posts and cables--fixed it promptly. Owner was convinced (by others) he needed a new starter. Charged him for a new can of cleaner and bottle of Gatorade. Similar example: heat shields on starters are very common if you install headers close to the starter to prevent heat soak starter failure.)

-Jason

Speedtoys

Shocking...and absolutely normal. If only there were threads about alternators and draw.

But you have a poor component or a leaking hose once hot..or something else...

Not related to your alternator.

merchauser

when my car is NOT in what I will call "stall mode", my volt gauge barely moves to the left as I add accessories. when I do see each accessory dropping voltage,
I know I am in the red zone, and car will stall coming to a stop.. intermittent issue for sure, and agreed, not alternator related

visually my battery ground strap looks good, but i wonder about this knurled piece I use to secure the strap to chassis. the contact area is only
the area of the nut. could this be my issue? maybe should get a fender washer and a star washer?

Speedtoys

The contact area is to the copper plug in the chassis UNDER the strap. The nut and washer just holds it tight.

merchauser

alrighty then....moving along

should those contact areas be it with 80 grit and roughed up?

GregBBRD

GT engines require additional idle speed to not stall with the alternator at full output.

I fixed three GT's, last year, that had S4 chips in the brain. All three stalled, when hot and under load. All three had "rebuilt" brains with the incorrect chips in them.

The first one took a bunch of time to figure out...I checked the chip part number, in frustration, a day after starting the diagnosis. By the time I fixed the third one, I had gotten smarter and checked the chip part number, first. Much cheaper repair, than the first one.

BTW....you guys are aware that I build a custom Bosch high output alternator, so you don't have to drive around with the battery draining, right?

SeanR

There is one "rebuilder" who does this all the damn time, and the reason I wont' use them. Hell, there might be two of them in the game now, which is why I will only use JDS for those and swap the chips. Keep my rebuilt unit on hand, order another and swap the chips.

GregBBRD

I figured that was what was happening.

Speedtoys

Do the same as you did with all of your other ground points you cleaned up, AND each of the terminal rings..you did those too, right?

FredR

The obvious question - what speed does your GT idle at?

You spent a long time chasing an idle issue as I recall.