Quote Originally Posted by AvionicsMaster1 View Post
If you've got a PBP2.6 manual I recollect there are hard numbers in it for isolation resistance. I thought the desired value from the old manual was several hundred kohms but I don't see it in the PBP3 manual.

If you look here http://ww1.microchip.com/downloads/e...es/_91017b.pdf it says 1kohm isn't enough. I have found an LED to ground on the PGC or PGD pins, even with current limit resistor, causes problems. I also remember that a capacitor on the MCLR pin caused a problem.

Just FYI, all these recollections may not be relevant to what you're designing. From experience I now use a switch to disconnect the PGC/PGD and depending on use the MCLR pin from the circuit for ICSP. You can get surface mount components that are very tiny.
Could you please point me to the surface mount switches you're referring to?