Chevrolet Repair: I have a chev c30 1977. I..., chev c30, clutch plate

Question
I have a chev c30 1977. I had a problem with the brakes leaking, and thought that was the reason for the screaching sound.  I had brakes fixed and after about half hour of driving there is a on off screeching noise.  The engine itself runs perfectly even when noise is screeching. It does not do it when idleing. The only thing that i can feel with this is when i put my foot down hard on the brake, I can feel a grind.  I use this as a horse truck. But i do not, push it hard and have it mechanically looked at reguarly, It never heats, it never uses oil, and it has never broken down, but this noise is intermitant, and has been hard to find.  WOuld be good to be able to have somewhere to start.  Clutch plate?  the noise reminds me of something spinning under pressure, like a small motor (maybe starter) spinning.  I had a second hand starter motor put in and this noise started not long after.

thanks
Katrina

Answer
Hello Katrina.
Did you know that your heater blower motor runs all the time when the ignition switch is on in that truck?
It may be worn out, and rubbing if you are slowing down.
Go under the hood, and find the wire that connects to it, and unplug it. See if that is the noise.
Should be over in front of the passengers area, on the firewall.


Van