Relay melted

[DJLapri]

I recently took a 400 mile trip hauling 6500 lbs of camper with my 5.3L truck.* Never thought to check out my dry cell during vacation.* Last night I checked it out for water level etc and noticed it wasn’t operating.* I have 2 fuses in the system,* 1 located between the on/off switch and relay (powered from windshieldwiper fuse), and the other inline between relay and battery.* The 30amp fuse located in the switch line fried.* I replaced it and the system still wasn’t working.* The 2nd 30amp fuse was ok, continued to check things out, disconnected the Relay and noticed that the inlet side was partially melted. **There is my problem.*
The relay is located along the outside wall of the engine area tucked alongside the battery. Why would the relay melt?

[DJLapri]

PWM set at 15

[giga pipe]

what was the current capacity of the relay?

I bought a 50A relay from AutoZone.

[nst6563]

If all else fails, I have seen relays run in parallel. I've never done it, and I don't think I'd recommend it..but it could be a bit of redundancy in the case you had of it melting.

[BioFarmer93]

-The relay is located along the outside wall of the engine area tucked alongside the battery. Why would the relay melt?

Probably not a continuous duty rated relay, or perhaps defective.