When i turn on the fan (Heater/cooler) i have to slap the dash hard and the fan comes on. With the fan running, i push the air con button and either the fan will cut out straight away, or the air con will run for a few minutes and then cut out. I can hear the relay cutting in and out when this happens. I have to hit the dash hard again for it to come back on. Most times i just crack the shits and turn it all off.. I replaced the resistor in the plentum about 18 months ago & relays. It seemed to work more often then. I assume that its a bad connection in the wiring loom of the dash. Any ideas where to look
With all the hot days here in Central Vic its getting pretty unbearable.

Help..