Well, I got tired of the GPR being undependable so I bought a Stancor and installed it in between snow storms. I have a LED installed, (great little mod) and now I'm not seeing the LED light up when I turn on the key. The WTS light comes on and cycles but no LED. I've noticed that the LED will come on after the truck starts and then shuts off after 30-50 seconds. I also have a push button as a back up on the GPR, but I can't get it to light up the LED either. I have been plugging in the block heater at night, but didn't last night as a test. I thought maybe I had a bad LED. Well, my truck would not start this morning. I had to jump the hot side of the Stancor over to the GP wiring. Has anybody had a Stancor go bad? I bought this one brand new!!!

 

i had the very same problem with 2 586-902 .. i then ran a thread here asking about the 586-903 and was laughed at and told it was not worth it... https://www.ford-trucks.com/forums/8...586-903-a.html

do what you want but i asked on PSN and was told to do it.matter of fact..many over there had to do it......the 903 has been in my truck for over a year now with no problems.. i run 1000 amp batts...when GPR is turned on they get a 14A shock then slowly drops bellow 12A.....not sure if that has anything to with it..

 

Make sure the black lead of the LED is going to ground.

 

LED's are very over voltage sensitive. So unless you have a cap to shunt the power away, you'll kill the LED.
It comes on after the truck starts due to the power useage on the system as well and the fact that the alternator is running then.

They are just so finicky on their power source, thats the best advice i can give you. You probably are loosing to much power someplace or you over voltaged it. I would bet the second one.
An LED will still work after being over voltaged, but just not as bright, and will require more power to get less light.

 

if it was a problem with the LED its self..then why wont the truck start unless he crosses the 2 lugs??

 

It's not a cap, it's a series current limit resistor.

 

Just reviewed the thread you linked to, Ron. My ScanGauge reports about 11 volts when the glow plugs are activated, even after starting the truck. When the relay releases, it jumps a volt or two. Don't know if that helps or not. But that right there is why I didn't do the LED mod. I can see on my gauge when they're on and when they shut off easily.

And something is clearly up with the OP's system. Are you 100% sure the relay is wired up correctly?

 

I'm still at a loss as to why the "stock" GPR was functioning and the Stancor won't under normal circumstances? Does the Stancor require a certain voltage to activate it? (I'm not an electrical genius by any means and the dumbest questions are the ones not asked.) I'm considering putting the stock GPR back on the truck.

 

mine will hit 13-14 Amps when key is truned on then it drops down bellow 12Amp..i have a gauge too..it reads the same as my hand held meter..i havent had a problem since i put on the 903 and neither do the handfull of guy's on PSN....

 

Again, are you 100% sure the relay is wired up correctly?

 

Amps or volts, Ron??? I'm not sure what you're telling us here...

 

Lift the wires on the small terminals so that no potentials are sent to the PCM. Then put battery on one terminal and ground on the other. If it is good you should here it operate. Polarity doesn't matter. If it does operate then check the two large terminals. There should always be battery on the hot side large terminal (the one with the boot on it) and if operated it should be passing battery to the other large terminal and onto the GPs. If it doesn't operarate or pass the battery then of couse the relay is bad.

If that passes turn key on. The small red wire should have battery and the other ground. If not there is a problem with the wirng to the PCM.

 

I just put the stock GPR back on, no problems and it works just fine. I double checked the wiring before I pulled the Stancor off, it was wired correctly. I guess I will stick with the stock GPR until it dies and worry about it then.

 

Im sorry i meant Volts... when i first hit the key the GPR will see 13-14 Volt then drop down to around 11V for the 30 seconds the GP's are being charged..at that point the WTS dash light goes out and i fire her up...now that she has started and is now running.. my alt puts out about 13.75V...for the next 90 seconds the GPR is still running the glow plug's..for that 90 seconds its seeing 13.75V... when the GPR shuts off..the live side of the GPR will still always see 13.75V as long as the alt is putting out..

 

The LED requires nothing other than an inline fuse to protect it. If it is wired to the glow plug side of the GPR it will work just fine as long as the GPR is working fine. You cannot over power it wired up that way.