Dash lights out again

I have been trying for some months now to find the problem of a dash light fuse blowing.In Aus I can only buy 3amp in the length required,(a 4amp is recommended) would 1 amp make a difference? most forums suggest a short some where, but where does one start to look for such a pesky problem? When a new fuse is fitted it usually takes some miles before it blows,I became aware of it only after a clock overhaul, when I plugged everything back together the fuse blew immediatly , suspecting the clock I re-mounted it in the housing using rubber grommets, although the clock is currently dis connected the fuse has gone again!! Ideas please!!      
Brent
Qld Australia
71 Grande 429cjr

Possibly that one amp does make a difference. You can always buy an aftermarket 4 amp fuse and holder and wire it in to bypass the old 3 amp fuse. You may have a short to ground since you removed and replaced the clock. That seemed to be when things went wrong. Back track and re-check everything and make sure nothing was disturbed to cause intemittent shorts or an unwanted ground. Make sure your dash lights are the proper ones for your car. Buy an electrical schematic or find one on-line to help toubleshoot and understand your cars system. In some systems the headlight switch can cause problems. You won't know until you see your schematic.  

Brent1:
I have been trying for some months now to find the problem of a dash light fuse blowing.In Aus I can only buy 3amp in the length required,(a 4amp is recommended) would 1 amp make a difference? most forums suggest a short some where, but where does one start to look for such a pesky problem? When a new fuse is fitted it usually takes some miles before it blows,I became aware of it only after a clock overhaul, when I plugged everything back together the fuse blew immediatly , suspecting the clock I re-mounted it in the housing using rubber grommets, although the clock is currently dis connected the fuse has gone again!! Ideas please!!    

I used to and to a limited extent still do automotive electric repair and it can be very difficult to isolate a short. (I had a car one time that only blew a fuse when it went over railroad tracks.) It really comes down to isolation. They make short-tracing kits that have a flasher element you plug into the fuse and then take an remote ammeter and start running down the wiring and watch it pulse, where it stops is the short.  You could also plug an inline ammeter and energize the circuit, knowing what the amp draw is will help you properly size the fuse.  Other than this it's a matter of physically finding a wire chafe or similar by visual inspection.
jlg  

By chance I was talking to a auto electrician who had some 15mm, 5 amp fuses, one amp more than recommended, after reconnecting the clock & all dash lights, & have driven about 100 miles the circuit has stayed good, I can only conclude the 3 amp was just under rated for the job.  
Brent
Qld Australia
71 Grande 429cjr

Hey Brent1 - I was just about to say that generally you can use a fuse with a slightly higher amp value and it should not cause a problem. I find this works in my old Harmon Kardon sound system where it wanted a 3.5 amp and now all I can seem to find is a 4 or 5 amp.  Have a good winter down there! Some of my inlaws are in Brisband. I spent a great week in Cairns and then another week north of Coolum Beach along the Sunshine Coast a couple summers ago. One of the best vacations ever!  

Hi Scott,
I live right near Coolum, may see you next time?  
Brent
Qld Australia
71 Grande 429cjr

Fairdinkcome mate! Look you up in the future when I get lucky enough to cross the pond!