Solving gauge mysteries

[mibars]

I'm in a middle of what I though will be a quick gauge bulb change that ended up being dashboard disassembled, checking gauges, cleaning and troubleshooting. All thanks to those odd (for me) bulbs that look like regular W5W or W3W, but are integrated into plastic sockets that need to be pulled from behind. Couple of questions that I have:

-How to remove speedometer from gauge cluster? I have electric speedo that connects to flexible circuit board, but I can't figure out how I suppose to unclip it from that board wothout ripping it
-Anyone had a problem with a trip meter not resetting? Mine doesn't react to the button
-Is it normal that I have a provison for a seatbelt warning, including a bulb, but looks like I doesn't have that feature? Not that I miss it
-I have only a battery warning, but there are two more provisions for idiot lights, what are they for? No bulbs and no cutouts in a screen so I have no clue.
-Is there a way to adjust speedometer? I have bigger wheels so my 55 mph is actually around 62 mph.

Things that I've already discovered:
-If your voltmeter reads too low you can add a resistor between "+" and that unused pin, parallel to the ceramic resistor. Mine needed if I recall correct 1000 ohm to make it point to "8" at 8 V, "13" at 13V and "18" at... 17V. I can live with that instead of 10 - 11 V when it's charging 13.5 V
-There is 0.2 V less on a voltmeter pins than on a battery, which skews volt reading a bit
-I didn't know that 700R4 came also with electric speedo


Oh and some engineer needs a proper slap for making those bulb sockets NOT ACCEPT regular W5W/W3W even if you rip the bulb off from that plastic. "Replace whole assy" my...

 

[Bennyt]

I can only help with one of your questions.

I have a problem with my trip meter on my '90 and I called a local speedo shop. He said it just needs to be removed and cleaned 99% of the time. I can't remember how much he wanted but I was going to bring the speedo to him and let him clean/ adjust/ lube whatever he does to the speedo and trip. I think it was only $75 or something.

Something else odd about my truck is that it has a mechanical speedo and it appears to be that way from the factory when '90 is supposed to be electronic. I know people say that it must have been swapped out but I have a hard time believing that they could butcher every other mod/ repair on the truck but somehow did a perfect job swapping in a mechanical speedo cluster.

 

[gmbellew]

you have to spin the trip knob, not push it, to reset the trip meter.

you can adjust your DRAC module for your tire size to correct the speedo. the DRAC is bolted to the dash metal under the radio. https://harristuning.com/Tbi/vssb-drac-calibration/

I think there is a clip or something to push in to remove the speedo. I've never done it. the electric is different than mechanical. electric was only 90-91 burbs and blazers. try hitting up the reference library and finding the GM manual that covers the cluster.

 

[mibars]

Pressing and spinning at same time did work! Thanks. I will look into that speed setting thing. By the way it's interesting how the speedo moves to a different resting spot when lying flat, it goes back to 0 when vertical