The other day while at a stop sign in my e99 F450, I went to take off and stalled. I am not sure if the stall was my fault or not; however, it would not start. I turned the key on and the wait to start light did not come on.


The first thing I checked was the mini 30 amp fuse under the dash that controls the GRP and the fuel bowl heater. The fuse was good, and my heater has been unplugged for a while anyway. Recently my SES light came on with codes that said the glow plugs had low voltage for both banks. I have cleaned the wires a couple times and the light goes out but then comes back on after a minute or so.


I figured that maybe if it was a bad wire it finally went bad so I got jumper cables and started to try and jump wires. I moved them around and found that when I hooked one side to the positive battery terminal and the other to the small key hot wire on the glow plug relay, the light would come on and it would start. I left the cables hooked up and drove the couple miles back home.


After messing with it I figured I could run a new wire. I got a fuse tap, and went from the 30 amp mini fuse that controls this system anyway, and ran it up to the post on the GPR for my new keyed hot wire. The WTS light would cycle and it would crank, but no start. After some more messing around I decided to put both the original wire back onto the post with the new wire that I had just put on; after doing this it started right up. I took it for a test drive and a couple times the engine would act like it stalled, only for a split second. When looking down at the dash immediately after the tach would be at normal RPM and the WTS light would be on, as if I shut the key off and tried to start it again.


I suspect it is the original key hot wire that goes to the GPR. It appears that this wire also has a purpose, other then serving as only a keyed hot wire for the GPR. It has about 6 inches off of the GPR, then it goes into the harness. Does anybody have any advice? Has anybody experienced this before? Does anybody know where that wire goes? If somebody could tell me where that wire goes, I will just run a new wire instead of having to dig through that harness... that doesn't look like something I would wish upon my worst enemy.


Thanks in advance!!!

 

For some reason it will not let me edit the thread.


After my test drive I cleaned every wire and terminal to a bright shine from the batterys, to the solenoid on the fender, to the GPR.

 

The GPR should not be related to your stalling issue. The things which come to my mind right away are as follows, especially since you've already unplugged the fuel bowl heater... oil sump level (yes, low level/pressure will shut you down), CPS, and ICP sensor.

You can pull the ICP sensor (DS head, about 1/3 back from the front, valley side), and see if you have oil inside the sensor housing on the head, and if so, could be time to replace it.

You can also swap out the CPS as another check.

 

I swapped out my CPS with one from the dealer, and it is doing the same thing still. I also changed my oil since it was time anyway, so I know it's not low.

 

If yours is like the 2000 f250 then there is a diode in the GPR circuit you can check. small plug in at the bottom right of the picture. In the wiring diagram its left side in the nbr 30 fuse circuit. could be the PCM relay itself

 

I switched the diode with one from my ranger, I wish I had good news.

i think the problem isn't even the truck... I think it's another truck. Every time I talked about getting something better on fuel as a daily driver (bouncing around in an F450 everywhere is expensive) something would break. I bought a ranger a couple months back and I've had nothing but problems!! Friggin trucks are worse then women sometimes...

 

Check fuse 24 or check for power coming into the PCM relay. When you hot wire the GPR you are back powering all the other items that are also attached. See the wiring diagram above and find arrow "E". If I'm reading it right this is where you are supplying power with your jumper. It should be coming from the PCM relay.

 

I wanna say, that wire in the loom goes back to the pin connector atop the d/s valve cover. I had/have same problem but with the orange wire(pcm ground). Ran a white to switch, to activate it

 

I figured that my batteries are past time to replace so I'd get new ones anyway, because bad batteries can make diagnosing hard, or can simply be the problem. New batteries and still the same issues. I also looked at the ICP and it has oil in the connector, I know that means it should be replaced, could that be my issue with the stalling?

 

Is the WTS light still coming on right after the stalling event?

 

Yes it is, I'm not sure why

 

When the PCM is first powered up is when you get the WTS light. It will stay on for a given amount of time based on the temps. I suspect your problem is that you are losing power to the PCM intermittently and it causes the truck to stall. as soon as power comes back it starts running again. Your seeing the WTS light because the PCM is going through it's power up routine.

In your first post the WTS light would not come on indicating no power to the PCM. Then you jumped the glow plug relay but what you did was provide power to the PCM through the back door. Look at the diagram. By putting power on the GPR you powered the IPR, and PCM at pins 71, 97, and 83.

You need to try swapping out the PCM power relay and look for loose or shorted wires going to it.

 

I switched the PCM with a spare that I have, it has the same issues. I also watched my radio after the truck had an episode, the clock did not reset so the problem must be local to the PCM like stated. Are there any fusable links that I can check?

 

I found out a couple days ago it was a fuse!!! Under the hood a 30 amp in the #24 spot. It was barely blown, and I think allowing some current still so it was kinda working and would cut out randomly. I will admit when I checked the fuses the first time I only looked with a flashlight, I didn't pull them; since it was not blown much I didn't notice. I am trying to figure out what caused it to blow now, I started a new thread since this one is not pertinent anymore.