Electrical issues... or something more?

[scutulatus]

Hello there. I have an '87 SE that I'm having some trouble with and wanted to see if anyone on here would know better about what's going on.

 

I went to start it one evening and noticed the oil pressure gauge was reading at 0. It sat there for a couple seconds, then climbed all the way to 120 and past it. The fuel gauge was also past the full mark, battery voltage was where it usually is, and the temp was still warming up. I've had the gauges fluctuate before and the truck seemed like it was running normally so I drove it to where I was going, about ten minutes away, thinking they might settle down. Well by the time I get to my destination, the temperature gauge is also reading past the far right mark, and the truck is still running fine, but now I'm worried because I don't want it to actually be overheating. I looked it over once I parked and couldn't find anything odd, but I sat there and wanted to see if the temp gauge would cool down, and it did so pretty quickly. I decided to drive it home and tried running the heater to see if it might make the temp go down, but no change. Fuel, oil pressure, and temp all still reading past max and battery voltage still normal. I checked the oil and coolant; the oil was changed recently and looked a little dirty but normal, full, and the coolant was also full and bright green. I pulled the dash cluster out thinking maybe I might find something but everything looks clean and tight. After poking around on the common problems thread, it seems like someone went the three-pin regulator and solder the wires onto that route before me to replace a previous faulty voltage regulator. I'm not sure where to go next. Wiring is not my forte and I'm new to these trucks, please have mercy on me. 

[Mr_Reverse]

It does sound like a bad regulator on the cluster. 

Tests you can do is turn the key on, engine off and see what the gauges do. If they max out again, unplug the sender for the temp gauge and see if it drops. Do the same for the oil pressure. If they drop, odds are pretty good the regulator has failed.