Where is the gp sorensen mr78 relay on the 1991 lumina apv?

Answer 1

I went searching in my APV for this relay because an Autozone clerk sold it to me as a fix for a voltage fluctuation. While driving and monitoring with a ScanTool, the system goes from about 14V to below 12V, and the headlights dim, the power windows can only creep, the cruise dies, and the heat gauge maxes. There seems to be no pattern, or relationship to the open/close loop, radiator fan, coolant temp, even engine speed. The drop comes and goes, maybe every 10 to 20 minutes. After taking apart most of the console and searching under the hood, I found the relay behind the air compressor control panel behind the back seat. I had disconnected the relay years ago because during suspension repair, I had abandoned the load levelers, and the air compressor kept pumping until the relay was disconnected. Today I reconnected it and snipped 2 wires at the actual pump to kill the compressor, and replaced the relay. And yet, the up/down voltage continues. What the heck is going on? The "HATCH AJAR" indicator also went off after years of staying on... but came back on. And where is the sender for this warning light??? Thank goodness the APV is just a boat tow vehicle, and I also own a Prius.