blowing speedo fuses

my friend has a 1994 astrovan, it keeps blowing the fuse for the speedo and a couple of other gauges, when it does this it will not shift properly we installed a new battery on the advice of a mechanic and had a canadian tire mechanic check it out for three hours but it still blows this fuse any ideas or helpful hints would be appriciated. :shakehead

my friend has a 1994 astrovan, it keeps blowing the fuse for the speedo and a couple of other gauges, when it does this it will not shift properly we installed a new battery on the advice of a mechanic and had a canadian tire mechanic check it out for three hours but it still blows this fuse any ideas or helpful hints would be appriciated. :shakehead
sounds like a short somewhere

I've used lamps in place of fuses at times. Probably a lower current lamp (like a marker light) will work here. The lamp limits the current so nothing burns up. Wire a lamp into a blowen fuse, and plug it in. It should pass enough current to let the guages work, and the lamp will be dim. If it's a short circuit, the lamp will at full brightness, or nearly full. Now start looking. When you find a fault, the lamp will dim. If it's intermittent, the lamp might light up when hitting a bump, letting you know a loose / bare wire is hiitting something. Good luck.