1998 Dodge Caravan Fuel Gauge drops in reverse

To answer your question, NO. I'm looking at a wiring diagram of your vehicle. The fuel level sending unit(in the tank) has it's own ground and sends a signal to the body control module via the dark blue wire. The body control module, in turn, tells the guage what to do. It sounds like there may be a bad connection somewhere. When you put the van in reverse, the engine will 'rock' in one direction and when you put it in drive, it will 'rock' the opposite direction. Some movement is normal. The motor mounts allow a little movement. I'm wondering if, when you put it in reverse, the engine moves enough in the right direction to interrupt the signal, either from the tank to the BCM or from the BCM to the instrument panel. Try the 'wiggle test'. Turn the key ON and have a partner sit in the van and watch the fuel guage while you wiggle wires under the hood. Try the larger wiring looms first. Just shake them around pretty good and see if the guage acts up. If it does, you'll be able to pinpoint where the problem is. If it doesn't, start the engine and have someone put it in reverse while you watch under the hood. Look closely at what all is moving when it goes into reverse. Does it stay incorrect as long as it's in reverse or is it just momentary? Try this and repost. We'll investigate further if we need to...