Have a short somewhere, losing power to FSS

[yARIC008]

I will buy a nice test lead with a beeper and light, i just bought a fox and hound yesterday to maybe help me trace out the wires too. On the tranny, one thing i did work on recently was the heat shield on the passenger side. It was cracked and making a loud vibration noise. I built a new one to replace it. I played with those wires behind the shield last night but found nothing.

I will try disconnecting alternator tonight. I dont see how braking coorelates to this though.

I have a question, what controls the fuel heater? I repaired a leak on that a couple months ago. I believe the fuel heater is on that circuit. I dont know whatvturns it on and off though.

 

[Wellused]

Actually,with a bad ground path(possible) when the brake lights are on that circuit could be searching for the path of least resistance..prob that low glow on the o/d light as well.Prob finding a grnd path thru pcm and brake light switch.I havent fooled with fuel heater yet so cant help on that one

 

[OLDBULL8]

Why do you cancel this on your post. ( Ford 1992 E-350, 6,900 lbs. ) ?

Maybe these two diagrams will help, not much difference thru the years.

 

[Ruger_556]

Actually,with a bad ground path(possible) when the brake lights are on that circuit could be searching for the path of least resistance..prob that low glow on the o/d light as well.Prob finding a grnd path thru pcm and brake light switch.I havent fooled with fuel heater yet so cant help on that one

PCM? Trans controller maybe...

 

[skeeter72]

I'm having a similar situation here's my thread. http://www.oilburners.net/forums/showthread.php?t=65997.
In there you will find a couple different wiring diagrams. Basically I found it helpful to have the side by side because each are a little different. The o/d light barley glowing means your PCM/EEC is not getting enough power. Thus causing the limp mode. Good luck.


Sent from my iPhone using Tapatalk

 

[pfarmer]

Bought an 04 6.0 one ton from a guy and it had the same kinds of issues you are having. He took it back and forth to the Ford House for 2 years. They'd soak him, send him home then it would start up again. He tried to trade it, they offered him 5K for it. That pissed him off and he stuck it in his barn and left it there. offered to buy it, gave him 8K for it, took it home, and found the problem in 10 minutes. The main battery cable was damaged. It was in a really inconspicuous place and no one had found it. Put all new battery cables in it and it's good to go. I know you've looked at everything you can think of, but you might check the cables from one end to the other. Couldn't hurt, you've done everything else.

 

[yARIC008]

Why do you cancel this on your post. ( Ford 1992 E-350, 6,900 lbs. ) ?

Maybe these two diagrams will help, not much difference thru the years.

Umm.. not sure why signature wasn't there. If you're talking about the html link in the signature, it's a long story. Hope to get it back one day.

The diagrams are very useful, I will be saving these.

I think I MAYYYY have found the problem tonight, and these diagrams tend to lend credence to the solution. When I had been working on the fuel heater previouisly I apparently never hooked it back up and accidentally left the connector just dangling back behind the fuel filter. I reached back and grabbed the connector, it was ****** dangling back there on lots of stuff... When I grabbed it and touched it to metal it sparked a bit. When i held it against metal it blew my number 7,30 amp fuse in short order. The fuse that has been the culprit. So anyway, not needing the heater I taped that off. I was thinking the fuel heater was only on when it was cold but according to your diagram it's always on when the switch is on. I was somewhat ruling this out based on the fact that it wouldn't be on when the engine was hot, but it apparently is not off when engine is hot.