1992 Volvo 940 Car Stereo Installation Diagram Whether your an expert Volvo 940 mobile electronics installer, Volvo 940 fanatic, or a novice Volvo 940 enthusiast with a 1992 Volvo 940, a car stereo wiring diagram can save yourself a lot of time. Automotive wiring in a 1992 Volvo 940 vehicles are becoming increasing more difficult to identify due to the installation of more advanced factory oem electronics. 1992 Volvo 940 OE Wiring Harnesses & Stereo Adapters Volvo 940 1992, Aftermarket Radio Wiring Harness by Metra®, with OEM Plug and Amplifier Bypass. For aftermarket stereo. Metra preassembled wiring harnesses can make your car stereo installation seamless, or at least a lot simpler.