Help..plz!
Laughing Gas
Joined: Apr 2013
Posts: 1,049
Likes: 65
Ah! I get it. You ran it off the starter cable lug. Very clever and there's no question about it getting plenty of power! I may have to do mine that way.
I had a stater solenoid fail in such a way that the bypass wire remained hot. I came back to my truck with a dead battery and burnt wiring. Seems a prior owner had replaced the 20 gauge fusible link with something heavier. If I wired it like you describe that couldn't happen.
All I know is ford used a fusible link and not a fuse on the bypass because of its slow burn properties (otherwise why not a fuse?). Makes me wonder if the initial 12 volt jolt helps wake the pump up and get it moving?
All in good fun and thanks for the learning! Here's a simple schematic showing the relative location of the resistor wire and other electric fuel system components in my single tank 86 E350. Can't vouch for the color coding.
I had a stater solenoid fail in such a way that the bypass wire remained hot. I came back to my truck with a dead battery and burnt wiring. Seems a prior owner had replaced the 20 gauge fusible link with something heavier. If I wired it like you describe that couldn't happen.
All I know is ford used a fusible link and not a fuse on the bypass because of its slow burn properties (otherwise why not a fuse?). Makes me wonder if the initial 12 volt jolt helps wake the pump up and get it moving?
All in good fun and thanks for the learning! Here's a simple schematic showing the relative location of the resistor wire and other electric fuel system components in my single tank 86 E350. Can't vouch for the color coding.
pedant
Joined: Jan 2008
Posts: 23,576
Likes: 40
From: EXTREME southwest CT
Brnfree, there is no diode in your diagram and power from the fuel pump relay will try to run the starter motor.
Since the starter's current draw is so high it will melt the fuselink.
The resistor wire is going to get pretty hot too.
Since the starter's current draw is so high it will melt the fuselink.
The resistor wire is going to get pretty hot too.
Lead Driver
Joined: Nov 2013
Posts: 7,178
Likes: 1,174
I'm confused. Are you talking about the wiring diagram shown in post #16? I'm not seeing the path you've described that will try to run the starter motor. A cursory review looks good to me, but I haven't dug in too deeply.
Awaiting enlightenment...
pedant
Joined: Jan 2008
Posts: 23,576
Likes: 40
From: EXTREME southwest CT
If you shift the bypass wire to the starter cable lug, power will flow from the shutoff relay following the path of least resistance through the starter motor to ground.
The 20Ga. fuse link is then going to melt because it is FAR too small to carry the current the starter motor wants, and as long as there is oil pressure the relay will remain closed.
Lead Driver
Joined: Nov 2013
Posts: 7,178
Likes: 1,174
Okay, but not as the wiring diagram is currently drawn, right? I must have missed the comment about moving the bypass wire to a different lug.
As Emily Latilla would have said, "Nevermind..."
pedant
Joined: Jan 2008
Posts: 23,576
Likes: 40
From: EXTREME southwest CT
Sorry for any confusion.
Really I should have quoted his post and snipped all but what I was addressing.
That's a pita on my phone, as you lose the thread -and any context- on mobile, so I just responded inline to the post above.
Really I should have quoted his post and snipped all but what I was addressing.
That's a pita on my phone, as you lose the thread -and any context- on mobile, so I just responded inline to the post above.
Thread
Thread Starter
Forum
Replies
Last Post
Lngbeard
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
15
Apr 29, 2016 11:24 AM
LARIAT 85
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
1
May 25, 2007 10:49 AM
