After changing headlight bulbs and light related fuses on my Ranger and still no luck turning headlight bulbs on I took truck to mechanic (not Ford mechanic). Though I have still have high beans and all other lights (signal, small lights, break lights, etc/ ) my mechanic said the reason my headlights won't come on is the "Smart Junction Box" is corroded and needs to be replaced.

That's the good news. The bad news is my mechanic say to replace (after ordering part/junction box through Ford) will cost $500. That's total cost. I should of asked what cost of the junction box (alone) is but forgot to. And then it gets worse. Mechanic said he contacted Ford and was told right now they don't stock smart junction boxes for my truck and have no idea when they will. When I tried to pin a time line down, mechanic said he really has no idea when Ford would ship junction part. He mentioned another Ford order he put in that took nine months to receive part.

So I'm thinking of going directly to Ford and find out how much junction box cost, and then install charge and then how long to wait for part. Anyone else have this crazy issue with their Ford Truck? $500 is insane for a head light issue and I've already spent $40 on new bulbs and $64 on truck inspection with first mechanic. I guess I could call a few junk yards in area but feel I'm taking a risk, since replacement part could go bad and have no warranty.

 

This (corrosion in the SJB) is a known issue on 2004+ Rangers, although I haven't heard much about it happening on the newer models like yours.

Since your truck is over ten years old now, it's not likely that Ford will be remaking this part. They are likely relying on leftovers from the factory and new old stock on dealer shelves. You will have to do some serious digging to try and source one on a dealer shelf somewhere or take a risk and pick one up from the salvage yard.

You may still get lucky going the Ford route, but just don't get your hopes up because they do have a timeline for when they discontinue certain parts for vehicles.

 

Fordzilla - thanks for reply and I do think you spelled out my (unfortunate) problem correctly. Though I have not yet contacted Ford directly (through a dealership repair shop) I am irritated that Ford no longer stock smart junction boxes. My mechanic said Ford claims SJB are on back order and there is no ETA. Mechanic said when he called Ford he got something back about "intergalactic back order". What the heck is that? I see SJB on Ebay which might be a better way to go than visiting a junk yard, but again it seems a crap shoot with no warranty and then wondering if replacement box will match up properly and the how long will it last.

Oddly I did find out that you can legally drive with high beams on (which my Ranger still has) but wonder how many near by drivers I might upset with bright lights on. Always thought Ranger were trucks you can work on but this problem is really out of my repair range.

 

One of our former members who I know on a personal level had a corrosion issue with his SJB on his 2004 Ranger. He did not replace the SJB, he simply neutralized/cleaned the corrosion and that fixed the issue. It depends on how bad the corrosion is, but you may not NEED a new SJB, just somebody willing to clean/neutralize the corrosion.

 

Whoa - never thought of that but worth looking into. The mechanic just showed me a picture on his cell phone of "supposed corrosion", and to be honest it was hard telling what I was looking at. Mechanic said the following - "water must of gotten into junction box and corroded things. When I pulled panel apart and pulled one of the connectors out I noticed blue crust all in one of the connectors". Well I should of asked mechanic why he didn't clean off crusted connector and then reinsert it.

I'm a little confused between a ranger fuse box and then so called smart smart junction box. When I asked mechanic where the SJB was located he pointed to fuse box cover on passenger side flooring. Well that where my ranger fuses box is. So just saying when I pulled off outer plastic cover off fuse box everything inside looked dry and undamaged to me. I found a few minor cobwebs and that's all. Certainly didn't see any water damage on various fuses. Now I'm aware the engine area has a fuse box possibly called junction/relay box but (again) mechanic said the problem was internal on passenger side floor area - pointing at fuse box. Also I don't believe the engine fuse box/junction box ties directly in with ranger headlights.

Now I don't want to lose my other lights that work (especially signal lights and break lights along with high beams) but I'll certainly explore the cleaning up option. Wonder if some small cotton swabs and special cleaning agent that won't harm connectors might be worth a go?

 

It's definitely worth a shot. For what it's worth, both the SJB and the BJB (Battery Junction Box Underhood) have fuses for the headlight system. The Battery Junction Box under the hood is not prone to corrosion like the Smart Junction Box is.

 

Where is the SJB located? Pic? I may just take a look and inspect mine.

Thanks Gents!

 

Passenger side kick panel. You need to remove the kick panel, and then unplug the connectors. Usually, the corrosion is between the connectors and the junction box.

 

Thanks! I will add this to my checklist!

 

If you don't see anything, you can also remove the SJB and flip it around to see if there is any corrosion or water damage on the circuit board. Some say that even a slightly leaky windshield can provide enough moisture to corrode the SJB.

 

I’m curious. What led you to replace the headlight bulbs in the first place ? Was it the same issue of high beam working but not low beams ?