Blower motor weirdness

[ddarnell]

Now that the temps have dropped into the 20s here in the great Pacific Northwest, the blower motor in my 76 W200 starts acting up. As soon as I start the engine it will run (with the switch on of course) for about 2 minutes and then shut off. It will NOT start running again until I turn the motor off and restart it. Doesn't seem to matter how long the motor is off before restarting, and will not run more than a couple of minutes. Almost as if it had a reset button, if you know what I mean. ????
David

[yogibare143]

I had a switch cause the same problem once. Best thing to do is install relays between switch and resistor. Blower motors tend to pull more current as they get older and switch can't handle it.

Can also cause fuse block to melt. Make sure your fuse panel is ok

[The Other Ross]

Make sure it is well grounded to the cab and the cab to the frame.Lack of ground raises resistance and melts the already weak switch and fuse block.

[Andyp]

switch

sometimes those switches are funky. I had the same issue in an '85, replaced it $12, and never had any other problems.
Andyp

[DODGEBOYS]

yup switch heating up and shutting down

[ddarnell]

It appears the problem is originating in the fusebox. Some heating up and cooling down going on in there. Haven't had a chance to yard it out and look at it though. Thanks for everyone's help!
David