3.0l 2WD Sport. Taillights and Parking lights out. Dashboard and dimming is down too. Replaced fuse (31 in passenger fuse box). Nothing. Checked voltage and no power reading at all to fuses 26 thru 31 in passenger fuse box. Replaced all three fuses in main fuse box feeding passenger box (F1, F3, F5). Nothing. Replaced headlight switch. NOTHING!


A bad wire maybe??? Help, dudes!

 

Welcome to the forum

It would be a 2004 -2011 Ranger if it has an SJB, but what year?

There is a Parking light relay, it also powers the dimmer/dash lights

 

Sorry. Forgot to mention it’s a 2006. I didn’t find any parking light relay listed in any of the manual’s diagrams. That’s what’s most frustrating. Is it hidden in the cigarette lighter or something? Lol.

 

Yes, it has one, in the SJB

The head light switch is a GROUND switch not 12volt

When you turn Parking lights on the Main switch grounds the Parking light relay,
it closes and sends 12v from fuse 31 to Fuses 1(dash lights) and 2(SJB) and sends 12v to front parking lights(brown wire) and rear parking lights(black/pink stripe wire)

But you say fuse 31 in SJB has no 12v, and it should have full time 12v, its not a key on key off circuit
Until fuse 31 has 12v there would be no parking lights or dash lights, its first in line in the circuit

Fuse 31 gets full time 12v from Fuse 1 in engine fuse box, 40 amp

This 12v is a dark green wire that comes to the SJB on connector C2280A

I would unplug this connector and check for corrosion, then plug it back in


Battery+ -------------fuse 1(engine bay)------------------------------[fuse 31---parking relay](SJB)----------------------parking lights

 

A little corrosion. Dark green wire looks a little overheated maybe. Connection seems proper. New connector needed possibly? I’ll clean her up and plug it back in and see if I get lucky.

 

If you hook battery back up and test the dark green wire it should have 12volts, if not then issue may be in the engine fuse box, Fuse 1 connection

The SJB did have corrosion issues because of its location, antenna gasket can leak and it runs down into that area

 

Ok. So I did get full voltage back for, like, a minute. Didn’t see no parking lights come on though. Checked voltage again and nothing now.

 

Ok I’ll check voltage to green wire...

 

Just a heads up
As voltage goes down AMPs required goes up

So corrosion on a connector lowers the voltage but the device being powered still needs the same Watts so amps increase causing wires to heat up

Say you have a 100watt load at 12v thats 100/12 = 8.3amps
at 9v its 100/9 = 11.1amps

I mention it because you said Green wire looks like it was getting hot, its connected to a 40amp fuse so could get VERY hot, lol
Green wire also powers several other devices/fuses

 

Making sure I got the right green here too. I’m getting voltage to all but that top left connection on the connector. Is that real dark green wire (almost looks blue) I got tagged with a question mark the one I’m after?

 

No, I don't think the one with the ? is the one you are after

Heres is the wiring diagram for SJB
Dark Green is on pin 1

You could pull out Fuse 1 in engine fuse box to confirm
Also fuses 3 and 5 to confirm those wires, that should give you the pin numbering Ford used

Diagrams are great but are not always accurate, especially for wire colors

But the dark green, dark blue and red wires are larger gauge, full time 12v with 40/50amp fuses, so seem to match diagram for C2280A

 

Right. Gotcha now. So, yeah, All three of the larger gauge wires read full voltage. Had previously replaced fuses and checked voltage at main F1, F3, and F5.

Still no reading at 31 though.

 

Oie. Ok. So, call me a newb, but maybe I should have checked this earlier: 31 DOES get power IF the headlights are turned on. I can hear what I assume is a relay clicking on and off when I put fuse 31 in and out of its slot. But no parking lights or dash still. ???????

Bad relay? Can I replace that?

 

On the 2006 Power 1 of 2 diagram I posted that dark green wire feeds 6 fuses including 31 test if any of the others have 12v

You will probably need to pull off the SJB to get to the back side

Read here: 2005 Range Edge Smart Junction Box SJB - Ford Ranger Forum
Unhook battery when you do this

 

Thanks so much for your help, dude! I ended up replacing the SJB (“eBay pick-and-pull). Plugged her in and everything’s back to normal! :D

 

Good Work

Thanks for the follow up and the FIX that worked