wig wag relay diagram

i just used the diagram for negative in positive out without isolation.. and it worked for like 2 minutes until the rheostat melted down.. so i tried again.. worked ...rheostat melted down... same with the 3rd time and suggestions?

Which diagram? What rheostat?

https://www.the12volt.com/relays/relaydiagram58.html this diagram.... and it was a rheostat, from a pump system at my work, pretty heavy duty 3 wire... i ll see if it has a model number on it...but like i said it worked for like 2 minutes you could adjust flash rate, but every time the relay clicked on a spark came out the rheostat untill it just melted down....is there a specific rheostat that would work better or last longer?

Just use a light bulb rated for the flasher - ie, ~55W etc. (Which will develop a bit less heat too.) Personally I think it's a stupid way to go - better to use a flasher that does NOT depend on a load (eg - for LEDs etc, or a 555 timer or any multivibrator).