Ignition cable bypass at the fuse box
04-09-2015, 12:08 AM
#1
Ignition cable bypass at the fuse box
Ok. So Bobo has been starting on and off for the past several months. After a bit of troubleshooting the verdict is that the starter is fine - always starts when I give it power at the yellow w/ blue wire connector next to the battery, but will not start when turning the ignition key. The wire at the key responsible for the starter is the red w/ blue. It does give 12V at the connector at the fuse box. But no power leaves the fuse box going into the yellow w/blue wire. So, I checked all the reasonable fuses mentioned in the manual, all are fine it seems to me. After connecting a wire from the ignition key directly to the yellow w/ blue wire connector behind the fuse box the truck starts fine.
So, my questions are:
1. What could I have missed when checking the fuses or the fuse box itself.
2. I want to bypass the fuse box and connect directly the red w/ blue wire and the yellow w/ blue wire, and put an inline fuse. Any grave consequences that may follow? What amp inline fuse should I put there - maybe 10A?
Thanks for your input!
So, my questions are:
1. What could I have missed when checking the fuses or the fuse box itself.
2. I want to bypass the fuse box and connect directly the red w/ blue wire and the yellow w/ blue wire, and put an inline fuse. Any grave consequences that may follow? What amp inline fuse should I put there - maybe 10A?
Thanks for your input!
04-09-2015, 06:50 AM
#2
Mark
iTrader: (1)
Welcome to the forum...
04-09-2015, 07:47 AM
#3
Moderator (Ret.)
Did you check the relay at the fuse box that is used for the starter (R01 in the owners manual is for the starter solenoid)? In cases where there is a large current draw, a relay is used that is triggered by a switch (in this case, the ignittion switch) to provide the 12V needed for the starter (perhaps to this yellow/blue wire circuit).
Last edited by Mod (Ret.); 04-09-2015 at 07:52 AM.
04-09-2015, 09:35 AM
#4
Yes I did check R01. I swapped out the relays and nothing changed. One of them was quite hot though. 
What you're saying could mean that the ignition switch wire (red w/blue) triggers the relay? Then the signal goes out to the starter on the yellow w/ blue wire?
Is this correct?
What you're saying could mean that the ignition switch wire (red w/blue) triggers the relay? Then the signal goes out to the starter on the yellow w/ blue wire?
Is this correct?
04-09-2015, 11:19 AM
#5
Moderator (Ret.)
Could be...to be absolutely sure, I'd have to check my factory wiring diagram book, but its home.
If you google, you will most likely find, but there are a kajillion pics of F150 diagrams out there.
If you google, you will most likely find, but there are a kajillion pics of F150 diagrams out there.
Last edited by Mod (Ret.); 04-09-2015 at 11:48 AM.
