Is there an after market relay wiring harness for the A/C Blower switch?

[slipstick]

Basically, the title of this post asks my question. I have just replaced the blower switch in my 69 chevy C-10. I rarely drive the truck and the switch I replaced (as well as, the resistor and high speed relay) has been in service for a relatively short period of time. It seems like a relatively simple wiring modification which would include two relays for low and medium fan speeds could be developed. I have not found this item discussed or for sale as of yet.
The alternative is to just keep replacing switches.
Has anyone considered or applied the idea of incorporating relays in this switching circuit?
Thanks, Leon