Burning smell through vents, lost electrical (GEM module?)

[dudemancool1904]

Headed home this afternoon, had the windows up and AC on.
While on the freeway i started smelling a burning rubber or electrical smell. I thought not much of it, figuring it was construction or something.
The smell seemed to pass and after a few minutes i noticed my speedometer was dead. Also not working were the wipers, windows, and chimes.
I'm not the expert but a quick search leads me to the GEM module crapping out.
What's the best course of action? Guessing OEM from ford is NLA? anywhere you can recommend to get one of these?
What's the replacement procedure like? Just pull the radio?

thanks for your help.

 

[C420sailor]

Junkyard

Gotta dig in there and see what burnt up though. It would suck to get another GEM just to realize it’s the harness or something else

 

[J_C]

GEM does seem suspect. Yes pull the radio and it's on the left side. I'd get the part # off it and then look at junkyards or ebay for pulls... hate to think what Ford would want for one of those new, IF they still had any which I highly doubt. Not sure how close the part # needs to be to work, but doubt it needs to be exact. One thing in particular that may differ is the axle ratio of the donor, for purposes of accurate speedometer... or did all the 5.0L AWD 2nd gen have same axle ratio? Then again that closes the door to getting a GEM from a 4L Explorer, but obviously the closer the match the donor vehicle is, the better the odds of being plug-n-play.

Then there's that other option, if you're scrapping the old GEM anyway, could open it and do an autopsy with the chance it is something you can DIY repair with a soldering iron and discrete component swap. In some cases, this could even mean you acquire a replacement GEM then if not programmed for your vehicle, you swap the faulty component OR you swap the NVRAM chip holding the programming (being especially careful not to erase it with an ESD event) from yours to the replacement.

Heh, maybe I'm just making up nonsense, it is more of a exploratory situation and see what you find and can do to remedy the situation, but this kind of thing is easier to do on older electronics because of more through-hole and lower density, larger chips with legible markings on them, and more off the shelf ICs instead of OEM proprietary ICs like you find in more modern vehicles. Just sayin' if the old GEM is toast, won't hurt anything to pop it open and take a look, but then again you won't know if a replacement GEM doesn't solve the problem either, so I'd take a wait and see attitude unless it can be opened non-destructively... which it probably can be.

 

[dudemancool1904]

Pulled the stereo out after dinner tonight. The GEM is definitely toast, it stinks of burnt electrical. Opened it up and some electrical components appear to have leaked their contents out on the PCB. Took a photo of the part number and found a few matching ones online from electronics rebuilders for about $100. I’ll give them a call tomorrow and see who sounds the most legit and then go from there.

 

[J_C]

If leaked out their contents just means that some capacitors vented, that's definitely a DIY level repair and could be fixed a lot cheaper than $100 with some new caps from Digikey, etc major electronics house suppliers... fixed better than new, because cap tech vastly improved thanks to the electronics boom, and because you're not a bean counter trying to save 20 cents on every single component possible over millions of vehicles.

 

[dudemancool1904]

Took a look at the board today, it was one of the round resistors that was burned up. I replaced it with a similar one but no dice. I found lots of burn marks on the PCB, I think the whole thing is beyond my realm of expertise. I found a refurb one that matches my build numbers on eBay for $90 with a warranty. Gonna go that route.

 

[dudemancool1904]

Ok, swapped the gem for a unit that was working, same numbers. Still no functions. What gives?

 

[dudemancool1904]

Never mind! One of the burnt fuses I replaced wasn’t seated properly. After re seating it, works like a charm!