FYI: When you test the temp, oil pressure and fuel tank sending units, the first test you do is to remove the wire and ground it. If the gauge pegs out, that tells you the wire is good. However, if the gauges are pegging out while they're hooked up to the gauges, then that means somewhere the wires that aren't supposed to be grounded,
are.
You definitely have a short, though if all your gauges are doing that, it's probably not with the individual wires, more than likely it's up at the instrument panel. I'm sitting here trying to think of what they all have in common that would cause that, and the only thing that comes to mind is the instrument panel voltage regulator. I'm not an expert on these, so I'm just shooting from the hip here, but I'm wondering if your IPVR is bad.
![Hmmm :hmm:](./images/smilies/icon_hm.gif)