anyone know about 87 broncos?

Good luck with that.
Just install an aftermarket and be done with it.

The '87, '88, and '89 all had gauge issue.

that is where i am now
i installed a cheap mechanical gauge and snagged it under the windshield trim with some vacuum hose, simply because i didnt like driving around with an oil leak and no gauge

im iether going to have to get the stocker working or install a proper electrical one

i wonder if there is a way to test the sending unit on the stocker