yeah i did that, i wasn't sure if the SJB cuts power to the bulb after it sense an issue in the circuit. wonder if a grounding issue caused the solder to go bad...
No, it just measures current flowing through the circuit and triggers to display the warming message if the current is lower than expected by comparing a voltage drop across a resistor for each bulb monitored. It does not have the capability of cutting power by design, would only lose power output from an internal fault (as long as it has power input and the MFS or headlight, etc, triggering it).
No, a grounding issue could easily cause the bulb not to light, and could cause the circuit to display the message, but could not cause the solder to go bad.
yes - testing the VT-OG wire showed no power out.(rear socket or kick panel) the SJB is only a few years old as i blew one up before by accident. and it was 550 ish to replace. wish i asked for that back...
Absolutely, ALWAYS ask for high priced modules back. It is a common repair scam to claim one has failed then they sneakily repair the real fault instead and never tell you about that.
ever open the SJB? seem to remember its under the driver dash but there is also another little box control unit thing there. cant image its more than 20 minutes to replace with a new one and about $250 for the new sjb. but id feel unconformable trying to program it with forscan...
so if i go the solder route how do you open these "sealed units" it looks like its just a few clips, maybe heat gun if theres adhesive?
One step at a time. AFAIK it is behind the radio, next to the glove box. You should access it anyway to make sure that power is coming out on the pin going to the VT-OG wire, AT the SJB to be sure there is no fault at that point. After that point a wiring fault could cause it so you want to find the first point in the circuit that power fails.
It should be fairly simple to remove and examine it to determine if it has more than clips or fasteners holding it together. In the past Ford has not used adhesives that needed a heat gun, but with each passing model year, it wouldn't surprise me, but for now I would assume it is just plastic tabs or fasteners. If plastic tabs, remember they are old and will be less prone to crack apart if in a warm environment.
I do see plastic friction-lock type tabs on the perimeter of the SJB you pictured. Odds are you just need a small flat blade screwdriver, some finesse, and for it not to be cold during prying. It could help to have a spare credit card or whatever to wedge in as you work your away around the seam popping it open.
I like to point a hair dryer at old plastics to soften them first, but being an interior part, even if there are clips holding it together that break, duct tape or whatever would be fine to hold it back together after an examination. It's not like it needs to be sealed in an interior cabin location.
If it's just a bad solder joint there is no need to buy a new one. That is easily repairable as good or better than new. AFAIK, you cannot program it with Forscan which is only used to toggle established values in existing programming. I could be wrong, never tried that. Regardless if you pulled one from an equivalent vehicle at a junkyard it probably wouldn't need programmed.
There's no way I'd pay hundreds just to resolve a bulb out issue. Even the text display of the error condition should be possible to hack away with the existing module. If it's like the last generation bulb out monitor circuit, it just required severing a signal line on the PCB with an x-acto knife.