1993 f150 380k I had an issue last year (I only drive around 3k a year)for my blower motor only works on low speed i replaced the fan switch in the cab boom problem fixed great 😁 1 year later the problem is black not so great 🙄 so I think I have another problem I looked at the old part last year and looked like it got hot and melted a bit idk where to start to keep this from being an issue

 

Welcome to FTE
FYI you posted this in the 240 / 300 six motor area so dont know how much help you may get?
Up higher on the main area there is a 87 - 97 truck area and if you post the question there you should get more answers.
There is also a heating / cooling area you might look for an answer and post the question there but I dont know how many look in that area?

Now if you found the switch got hot could be from 2 things the way I see it.
Bad connection at the plug that will add resistance at that point and heat up or high AMP draw.
I would look the plug over really good to see if it is showing signs it has also gotten hot and replace it. Maybe replacer it any way just to be sure it is good.

High amp draw would be a blower motor issue. Could check how many amps it is drawing and see if it is with in spec.
Now dont go thinking high amp is a bad motor just yet but it could be?
Dirty coils, heat & AC, can slow / stop air flow so the motor has to work harder so I would make sure they were clean as a start.
There is a blower motor resister that works with the fan switch to control the speeds I wonder if that could be bad? I have had a non-Ford SUV melt the resister 4 times and the plug 2 times since 02 when it was new.

I would replace the switch and its plug, the resister pack and clean the coils and recheck the amps on the blower motor and if still high replace the motor.
Dave ----

 

I have noticed alot of the heat is around the plug I will replace switch and see if I can find a new plug for it. The blower motor isn't new but was replaced in 2019 due to no fan speed at all, ill be sure to check regardless to further diagnose the issue.

 

If the motor was pulling high amps and heated the plug then it may not clamp the connection tight enough.
Look at the 2G ALT they call the fire starter. There is so much load through the plug it heats up and get weaker to the point it melts the plugs and catches on fire, then the harness, plastic covering, etc., truck!
That is why I said replace the plug to the switch as it may not clamp tight any more and just keep getting weaker over time with eating up.
Also about checking the coils if dirty. A fan that can not push air has to work harder and put more strain on the system from motor back to the switch.
Dave ----