This has been an incredibly informative thread. I'm glad I left my alternator setup alone.

 

Thanks Andym. I'm glad you at least found it informative.

A year ago, I started a thread in this forum on this EXACT SAME ISSUE (High amp alternator effecting longevity of glow plugs) and only a couple of people (with electrical backgrounds) "got it". Everyone else couldn't seem to get the connection, with the consensus of group think at that time being "What does an alternator have to do with glow plugs... the voltage regulator should take care of everything." What I had then was a failure to communicate as well.

But there is something about Sous... his dogged determination to leave no stone unturned in pursuit of his goal stated clearly in his signature... that inspired me to raise the topic again, a year later. But this time, not in the form of a question or a suggestion, but in the form of a definitive declaration. I still can't produce proof of deleterious results from these facts. I can only present the facts of the concern itself, as demonstrated by the writings and measures that Ford and Beru each undertook in relation to this concern.

Here are some key visuals I posted in the other thread, from a year ago, which I will add to this thread, to keep the information on this topic as complete and as exhaustive as possible.

 

I'd also like to quote one of Larry's posts. His user name is Retired Sparky, which implies he spent his career working his way around an amp and a volt.

Read his quote below, imported from the other thread, carefully, and in the entirety, without skimming:



Larry understood the concern.

 

All this talk of relays and switches seems like overkill and a pita if the tuning can be changed to help protect the plugs...

 

Ok, for some reason I can't quote so the following is what I'm referring too.Originally Posted by Sous
We install a glow plug relay light to let us know when the glow plugs have finisned with their task and then start the truck.

 

John, the light is a 100% positive sign that the GPR is providing power to the glow plugs. When the light goes out, the glow plugs no longer have power supplied to them. People have installed this light in the past in order in order to not tax the battery system by providing power to the starter and glow plugs simultaneously.

I had the thought that if I waited until the glow plugs were not being provided power, based on what the light indicated, that I could start the truck with the glow plugs off. This would not only remove the "afterglow" that was mentioned on the previous page, but would allow me to have a 160 Amp alternator.

This does not appear to be the case though. As I understand it from what Y2KW57 has said. Once the light goes out and the truck has been started, the glow plugs could have power applied to them again, providing up to 2 minutes of afterglow, which would compound the problem even more.

I was hoping that when the glow plugs cycled on and then off, they would be on a timer or something so that they would not be lit again until the next full off, on, start sequence. Again, this is not the case.

I have the OEM 110 Amp alternator sitting in the box that the 160 Amp alternator came in. Instead of working on building up my wood shop this weekend, I might just swap teh OEM alternator back in and eat the $300 it cost me for the fancy one. Maybe I can take it out back and shoot it with my 7.62mm rifle from a distance as target practice.

Then, I will look for a suitable 110 Amp alternator that is reliable so that I don't have to do this all over again.

Can you tell I am annoyed yet? I absolutely hate it when I try to make something better and end up making it worse. At least the alternator is on the top of the engine can can be swapped out in about 30 minutes including a beer break.

I have an email out to Quick Start, but am not holding my breath.

 

It isn't the presence of, nor the illumination of, the LED light that plays a role by itself.

Rather, the role is played by the operator, who relies on said LED, by waiting for this LED to extinguish prior to starting the truck.

The concern there is after the PCM times the GP out, will starting the truck restart the GP Relay timer. IF that were to occur, then the concern about burn out would be present.

IF as long as the truck remained in KOEO, even if indefinitely, until the battery itself ran out of power, and IF the PCM remained in an awoken state, and remembered that it had already turned on the glow plugs once during that power cycle, then the concern would evaporate, and the plan would work.

The issue is, with "inadvertent power" circuits, timers, and relays that vehicle manufacturers build into electrical systems to save us from ourselves, I cannot saw with certainty that after a certain amount of time of KOEO, the timers in the PCM won't reset.

That specific point can be tested though, with the LED light. So the role that the LED light plays is to inform the operator. My advice to Sous was to use the LED light as an educational tool. In this specific instance, hook up the LED light, and see what happens after leaving the truck in KOEO for 150 seconds, or about 20 seconds after the LED light extinguishes, then turn the key to crank and let the truck sit for next minute or two in KOER.

If the LED light re-illuminates upon crank, then we will know that it is a bad idea to wait until the entire initial glow plug on cycle is complete. If the LED light never comes on again until the truck is shut off and the next ignition cycle is initiated, then voila... there is one simple (but time consuming on a daily basis) solution. Simply wait until the LED light goes out before cranking. Only you'd have to have a lot of patience.

So the LED light can play a key role in GPR operations... but only in combination with the operator.


Sorry to have caused confusion with my wording, and for not undertaking a simple test myself before postulating on possibilities. I have since tested what Sous proposed doing, as has Bill Kay, and waiting with Key On Engine Off for a full 2 minutes, and while keeping the key on, then starting the truck... will do exactly what Sous wanted. This has not been confirmed with GPCMs, only simple relays.

 

 

I have had the GPR light mod kit n for years and have never seen the light come back on after the original cycle. Maybe it does later on but I have never seen/noticed it. My truck hasn’t ran this week and I’m about to go see if it comes back on. It’s not cold here (50*F)but it’s not 131*F either. I’m at 1030’ above sea level if someone can confirm that the PCM will call for the plugs to re-light.

 

Ok. Just got back. The plugs did not re-light in my situation.

Sous, before you drop a firing pin on a stack of Benjamin’s, install the GPR light mod and see if YOU truly have something to worry about. I live in Ga too and we may not have the right climate to get a re-light signal from the PCM.

 

What's this talk about putting in a Hydra

I am coming over right now to put that bad boy into your truck to bring it alive!

Tim M

 

I'd be delighted. But right now I'm rebuilding your dad's old table saw!


And check you out with a full pull (of green chiclets) with less than a 1,000 posts. You must be doing something right in this community. I'm honored to be a part of your 1,000th post on FTE.

 

Reps sent!

 

Inspired by Bill, I just now ran a similar test and confirmed his findings.

I'm not sure why I didn't run this test before. Could have saved a lot of typing. But I tend to over think and under do, which like a birth mark, cannot easily be erased.

With a high current compatible test light lead clamped to the same relay "powered when on" post that the glow plug supply wires are connected to, and the probe/light part of the relay clamped to the driver's side negative battery post where I could see the light illuminate through the gap under the hood when open, I turned the key on. The light lit up.

And then I waited.

For an eternity.

And waited some more.

The test light FINALLY went out.

I waited a while longer. Then I turned the key to crank.

The light did NOT come back on.

Winner winner chicken dinner.

I shut it down, and cycled the key. Light came back on.

So, this confirms Bill's finding, and validates Sous's original plan, that I had earlier probed with uncertainty. Bill is right. Sous, you have nothing to worry about.

As long as you have the patience to wait.

And wait.

And wait.


But the good news is, you may not need to wire an LED. Just monitor the volt meter on your P3.

On my second test, I monitored voltage the entire wait period. The VPWR remained at 10.8v for most of the wait period, and when the voltage jumped to 11.6, I started the truck. I didn't have the test light hooked up on that test, and I should have. But the voltage rise was a rapid snap, not a ramp up. But I don't know the data bus polling rate of the APCM that I used to monitor voltage in tenths.

If nothing else, this thread identified a not so obvious issue, and found a rather simple solution. The next level of solution still remains to be resolved however. And that would be to reduce the wait time, by introducing a way either curtail or cut off glow plug operation after engine start, or limit the voltage the glow plugs see, to a level less than the internal voltage regulator in the alternator, once the engine is started.

While I'm on a roll here, I need to see about installing that little black box. Someone has been waiting very patiently while I've been away all summer and fall. Time to put thought into action.

 

Actually, what you were hoping for IS the case. As long as the key remains on, and isn't turned off before cranking to start, the glow plug will not recycle, even if the EOT is less than 131F.


I should have tested this before postulating on possibilities.


I also have a GMC truck that has a couple of onboard computer modules that do a full power cycle between the run and crank settings on the ignition. There are distinct and segregated power circuits that are hot in run, but not hot in crank, so when the key is turned to crank, those modules lose power momentarily before the key is relaxed back to run again. I didn't know if our Ford computer was subject to that kind of power scheme, so I posted about the possibility, based on the experience I carried over. In this instance, that experience did not apply.