Hi folks I have a 1990 740 wagon with a short at the number 5 fuse shorted it controls Glove compartment light, Clock, Radio, Engine compartment light, Interior Light, Trunk light, Antenna, Door warning, make-up mirror light. It pops the fuse immediately Is this a common problem with this vehicle and if so, where should I start?

 

its not a common problem.

typically to debug that sort of problem, you'll need to follow that circuit around and isolate (disconnect) each leg of it to see where the short is.

however, first, do you have an aftermarket stereo? I've seen a lot of /really/ botched stereo installs, you might just pull the stereo, and check the wiring to it, maybe the 'always on' wire (often yellow on aftermarket stereos, and often green-red on volvo 740s [at least on a 92 740, I don't have a 1990 diagram]) has come undone or is otherwise exposed and is touching the metal chassis or something, shorting it.

I note fuse 5 also goes to the radio antenna, you might check the wiring back there on the side of the trunk (remove the left side floor panel, should be a loop to simply pop it up for access). same thing, green-red on 1992, probably same on 1990

 

[re botched stereos, I've even seen installs where the $#@$#@$ just twisted the wires and used electrical tape, which long ago turned to krispy goo. one I fixed in an old GF"s car used masking tape :-/ a good job uses crimps, or soldered connections with shrink-wrap. also, a good job doesn't cut any original wiring, it uses a vehicle specific harness adapter, so the factory wiring isn't chopped up]