Starter backfeeding off lights

[OS1R15]

I bought a 1999 ranger a couple months ago, and I have been fixing it since. The previous owner did some janky splices at some point and before selling it to me took off a lightbar but never mentioned what it was spliced into.

If the lights are on in any position (excluding high beams), the ignition is in the run position , and i press in the clutch the starter kicks on even while the engine is running. The dimmer switch does not affect the dash lights at all ,and both the light and dimmer switches have been replaced with spares off a parts truck but hasn't changed anything.

I have looked inside the dash behind the radio bezel, passenger side, and driver side and found no splices atleast as far as i can tell.

Pulling the fuse to the dash lights in the fuse box inside the engine bay makes the issue go away but then I can't see my gauges at night. (previous owner did this to hide this issue before selling it to me) Pulling the fuse to the immobilizer also make it go away but that completely kills the starter and has to be done while running.

Im completely stumped at this point and dont know what to do since I drive at night very often for my current job. Any ideas or help would be greatly appreciated.

 

[franklin2]

You looked around a little bit at the lighting circuit and did not find anything. Next I would look at the starter circuit. it goes less places so it may be easier to find the problem, it does not spread all over the dash like the dash lights circuit does.

So what happens when you pull fuse #24, 7.5 amp fuse? Of course it will not crank, but does it still crank when you press the clutch pedal with the lights on? 7.5 amp fuse is located in the cab fuse box.

 

[franklin2]

Here is where "B" goes in your case with a manual transmission

 

[pjtoledo]

@franklin2
he stated no issue if headlamps were on high.
pull up the headlamp circuit, hibeams have a separate power source in the multi-function switch.
they also take a different route thru the central junction box.

 

[bobbywalter]

for now i would disconnect the trigger at the relay and run it with a separate button if you dont figure it out. driving at night is more important for me than further janking it up with another button. especially if i am getting paid.

 

[OS1R15]

You looked around a little bit at the lighting circuit and did not find anything. Next I would look at the starter circuit. it goes less places so it may be easier to find the problem, it does not spread all over the dash like the dash lights circuit does.

So what happens when you pull fuse #24, 7.5 amp fuse? Of course it will not crank, but does it still crank when you press the clutch pedal with the lights on? 7.5 amp fuse is located in the cab fuse box.

View attachment 131841

Starter doesn't kick on at all with fuse #24 unplugged

 

[franklin2]

Starter doesn't kick on at all with fuse #24 unplugged

Let me make sure of this. With fuse 24 unplugged, if you turn the lights on, key in run, and push on the clutch pedal, the starter does not kick on in error like it did before? But it will kick on in error with fuse 24 plugged back in place?

 

[OS1R15]

Let me make sure of this. With fuse 24 unplugged, if you turn the lights on, key in run, and push on the clutch pedal, the starter does not kick on in error like it did before? But it will kick on in error with fuse 24 plugged back in place?

Yes, with fuse 24 unplugged the issue stops and the stater will not kick on. With it plugged in it will kick on in error. I have also gone up the starter circuit. I found no splices. The relay and clutch pedal position sensor aren't damaged.

 

[pjtoledo]

disclaimer, this is a 2000 manual. hope it's the same for 1999
when fuse 24 is removed is there still power on one side of it while in RUN?
what happens when fuse 28 is pulled?

 

[franklin2]

Yes, with fuse 24 unplugged the issue stops and the stater will not kick on. With it plugged in it will kick on in error. I have also gone up the starter circuit. I found no splices. The relay and clutch pedal position sensor aren't damaged.

This is a tough one. The only thing I can think of in common with the lights and the starter relay is the grounding on the front sheetmetal of the truck. The only thing I can think of to try is take a piece of wire, crimp a ring terminal on it, and put that under one of the starter relay mounting bolts. Then run this over to the battery negative terminal and hook it there. Then see if the problem goes away.