1990 blows a fuse when shifting to reverse

Whenever i shift my 1990 5 speed into reverse it blows a fuse. This fuse operates the shoulder belts wont retract, the temperature gauge drops below cold and worst of all the radiator and condesor fans won't operate until I change the 7.5 amp fuse marked for gauges.

You're either using the wrong fuse or you have a "short" somewhere.

Since it only blows the fuse when you put it in reverse, the short is obviously in the wiring to the reverse lights. A common place for wiring problems in these Camrys is in the loom in the trunk by the driver's side trunk hinge. It rubs constantly from all the opening and closing of the trunk lid. Some wires can have their insulation rubbed off and 2 or more bare wires can touch each other causing the short. Open up the loom there and check for wires with their insulation rubbed off. If you find any, cover them with electricla tape or heat shrink and replace the fuse again and try it. This should solve your problem. If it doesn't identify the color of the reverse lights wiring by looking at them in their sockets and work back towards the front of the car looking for the short.

Good luck.

Mike