Relays Blowing

I have had 2 relays blow in the last 2 weeks . Headlights , Horn and my hazzard lights blew a fuse . They have all blown during wet weather , could this be the reason ??

Do the relays still click? Is so then the load on them might be too high and fry the contacts, or very bad location (getting sprayed with water), check for any gounded or rubbing wires in the circuit, I have found sections where the sheathing was simply missing, exposing and inch or so of bare wire. If they don't even click anymore the electromagnet is fried, the only time I have seen that happen is when the voltage gets too high, make sure your alternator is not driving the voltage too far past 14V.

As for the hazards, I believe the turn Signals us the same fuse, if you don't fry the fuse just using the turn signals then it is likely nothing is grounded. The fuse may have just been replaced with one that was too small, ( Check to make sure of the required rating, putting in too heavy duty of a fuse just means that it is no longer the weak point and will fry somewhere else.) High voltage could cause this too.

I have a Centech harness and a 1 wire 3g alternator . My voltmeter reads 14 volts most of the time but never over .
The headlights relays are in a bad location . They sit in between the core support and grill . I need to make some sort of cover. The horn however sits under the dash so I dont know . I does get wet from a leaking windshield inside the cab .

Most relays are not sealed. So moisture could very easily be the cause.
Try and make sure the terminals are facing down. That way the body acts as an umbrella. And get the relay out from between the core support and the grill. That is not a good place.