Anyone tell me what terminals are what on a 3 pin T3 fog light switch. I just seem to keep blowing fuses when I turn my lights on.
TIA

This should help you out,

http://www.type2.com/library/identifi/bosterm.htm 

83 = + from fog light relay (grey/yellow)
83a = to fuse S6 and fog lights (White/yellow)
31 = Earth (brown)

Spent the afternoon trying to wire up the light bars on the roof but seem to keep blowing relays as not getting 12V to the lights. Anyone have any suggestions or ideas that might be causing this? I ahve double and triple check my wiring and all seems correct.

The one I had ('89 with twin lights) was a great little truck, but the wiring was a right royal pain, just old and past it.

I had the exact same problem you have, and for me the reason was melted and burned out relay block holders. Where the power wires went into the connectors it had got too hot, then blew fuses and popped relays without fail.
Might be worth checking, and while you're at it, the lighting stalk switch wears with age and current, so check that too.

Thanks modnrod all sorted now. Was the idiot (insert me) wiring it up. Relays all working fine finally traced it to power coming from wrong fuse in fuse block.