VMM suddenly stopped working

66_Fairlane_289

Registered User
Anybody know why the VMM in my 90 sc would randomly stop functioning? Up until about a couple days ago it worked perfectly fine and then the display just stopped turning on when I first started the car but turned on after a few minutes, now it doesnt turn on at all.
 
... a/c clutch engages when it has Freon in the system.

That confirms the fuse/power is ok. If it was a problem w/the inputs, the VMM should still at least light up.

I'd want to pull it and be sure it's rear connector is still socketed. If it is, I'd guess the unit either needs it's connector/socket checked for corrosion and cleaned, or suffered a board failure. Swapping in a spare would be the fastest way to check, but that means having another one on hand, of course.

If you pull it, be sure to do it evenly - the plastic tangs on the sides break very easily so be very careful. Use a small screwdriver in the small slots on the sides on the front. It's also easy to mar the plastic on the unit and the opening so use care there too. it's held in by two metal tension clamps, one on each side, then slides out far enough so you can pull, the connector - it's release is on the top. As with many connections on our SCs now that they're older, it might just be an issue of removing the connector, checking for corrosion on it and the socket, then reconnecting.

If you have an EVTM, you could also probe the connector to at least confirm hot is making it that far. If you want to make that check and don't have an EVTM, speak up.

Good luck.
 
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