Ok, after my last post, I checked the Volvo Service Manual Wiring Diagrams for 1989 740's. It shows all of the possible engines for a 1989 740, which include 4 non-turbo and 1 turbo engine. It looks like the only the Turbo model has the fuel injection ballast resistor. This is engine B230FT with LH-...

On my 1989 740T wagon it is located inside the engine compartment on the drivers side fender close to the front of the car very close to the battery. In fact, I discovered this a few years ago when I removed and replaced the battery, and afterwards it ran terribly, very rough idle, engine shaking, a...